Merge #14555: Move util files to directory

2068f089c8b7b90eb4557d3f67ea0f0ed2059a23 scripted-diff: Move util files to separate directory. (Jim Posen)

Pull request description:

  As discussed [here](https://github.com/bitcoin/bitcoin/pull/14074#issuecomment-429090584), this establishes a `util/` directory to introduce more organizational structure and have a clear place for new util files. It's really not scary to review, it's just one big scripted diff.

Tree-SHA512: 39cf15480d7d35e987b6088d52a857a2d5b1802e36c6b815eb42718d80cd95e669757af9bcc7c04426cd8523662cb1050b8da1e2377d3730672820ed298b894b

9 files changed, 2796 insertions, 0 deletions

diff --git a/src/util/memory.h b/src/util/memory.h
new file mode 100644
index 0000000000..15ecf8f80d
--- /dev/null
+++ b/src/util/memory.h
@@ -0,0 +1,19 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_MEMORY_H
+#define BITCOIN_UTIL_MEMORY_H
+
+#include <memory>
+#include <utility>
+
+//! Substitute for C++14 std::make_unique.
+template <typename T, typename... Args>
+std::unique_ptr<T> MakeUnique(Args&&... args)
+{
+    return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
+}
+
+#endif
diff --git a/src/util/moneystr.cpp b/src/util/moneystr.cpp
new file mode 100644
index 0000000000..4c4de7b729
--- /dev/null
+++ b/src/util/moneystr.cpp
@@ -0,0 +1,77 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <util/moneystr.h>
+
+#include <primitives/transaction.h>
+#include <tinyformat.h>
+#include <util/strencodings.h>
+
+std::string FormatMoney(const CAmount& n)
+{
+    // Note: not using straight sprintf here because we do NOT want
+    // localized number formatting.
+    int64_t n_abs = (n > 0 ? n : -n);
+    int64_t quotient = n_abs/COIN;
+    int64_t remainder = n_abs%COIN;
+    std::string str = strprintf("%d.%08d", quotient, remainder);
+
+    // Right-trim excess zeros before the decimal point:
+    int nTrim = 0;
+    for (int i = str.size()-1; (str[i] == '0' && isdigit(str[i-2])); --i)
+        ++nTrim;
+    if (nTrim)
+        str.erase(str.size()-nTrim, nTrim);
+
+    if (n < 0)
+        str.insert((unsigned int)0, 1, '-');
+    return str;
+}
+
+
+bool ParseMoney(const std::string& str, CAmount& nRet)
+{
+    return ParseMoney(str.c_str(), nRet);
+}
+
+bool ParseMoney(const char* pszIn, CAmount& nRet)
+{
+    std::string strWhole;
+    int64_t nUnits = 0;
+    const char* p = pszIn;
+    while (IsSpace(*p))
+        p++;
+    for (; *p; p++)
+    {
+        if (*p == '.')
+        {
+            p++;
+            int64_t nMult = COIN / 10;
+            while (isdigit(*p) && (nMult > 0))
+            {
+                nUnits += nMult * (*p++ - '0');
+                nMult /= 10;
+            }
+            break;
+        }
+        if (IsSpace(*p))
+            break;
+        if (!isdigit(*p))
+            return false;
+        strWhole.insert(strWhole.end(), *p);
+    }
+    for (; *p; p++)
+        if (!IsSpace(*p))
+            return false;
+    if (strWhole.size() > 10) // guard against 63 bit overflow
+        return false;
+    if (nUnits < 0 || nUnits > COIN)
+        return false;
+    int64_t nWhole = atoi64(strWhole);
+    CAmount nValue = nWhole*COIN + nUnits;
+
+    nRet = nValue;
+    return true;
+}
diff --git a/src/util/moneystr.h b/src/util/moneystr.h
new file mode 100644
index 0000000000..9133f46d5d
--- /dev/null
+++ b/src/util/moneystr.h
@@ -0,0 +1,24 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+/**
+ * Money parsing/formatting utilities.
+ */
+#ifndef BITCOIN_UTIL_MONEYSTR_H
+#define BITCOIN_UTIL_MONEYSTR_H
+
+#include <stdint.h>
+#include <string>
+
+#include <amount.h>
+
+/* Do not use these functions to represent or parse monetary amounts to or from
+ * JSON but use AmountFromValue and ValueFromAmount for that.
+ */
+std::string FormatMoney(const CAmount& n);
+bool ParseMoney(const std::string& str, CAmount& nRet);
+bool ParseMoney(const char* pszIn, CAmount& nRet);
+
+#endif // BITCOIN_UTIL_MONEYSTR_H
diff --git a/src/util/strencodings.cpp b/src/util/strencodings.cpp
new file mode 100644
index 0000000000..5b8520030b
--- /dev/null
+++ b/src/util/strencodings.cpp
@@ -0,0 +1,599 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <util/strencodings.h>
+
+#include <tinyformat.h>
+
+#include <algorithm>
+#include <cstdlib>
+#include <cstring>
+#include <errno.h>
+#include <limits>
+
+static const std::string CHARS_ALPHA_NUM = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+
+static const std::string SAFE_CHARS[] =
+{
+    CHARS_ALPHA_NUM + " .,;-_/:?@()", // SAFE_CHARS_DEFAULT
+    CHARS_ALPHA_NUM + " .,;-_?@", // SAFE_CHARS_UA_COMMENT
+    CHARS_ALPHA_NUM + ".-_", // SAFE_CHARS_FILENAME
+};
+
+std::string SanitizeString(const std::string& str, int rule)
+{
+    std::string strResult;
+    for (std::string::size_type i = 0; i < str.size(); i++)
+    {
+        if (SAFE_CHARS[rule].find(str[i]) != std::string::npos)
+            strResult.push_back(str[i]);
+    }
+    return strResult;
+}
+
+const signed char p_util_hexdigit[256] =
+{ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  0,1,2,3,4,5,6,7,8,9,-1,-1,-1,-1,-1,-1,
+  -1,0xa,0xb,0xc,0xd,0xe,0xf,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,0xa,0xb,0xc,0xd,0xe,0xf,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+  -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, };
+
+signed char HexDigit(char c)
+{
+    return p_util_hexdigit[(unsigned char)c];
+}
+
+bool IsHex(const std::string& str)
+{
+    for(std::string::const_iterator it(str.begin()); it != str.end(); ++it)
+    {
+        if (HexDigit(*it) < 0)
+            return false;
+    }
+    return (str.size() > 0) && (str.size()%2 == 0);
+}
+
+bool IsHexNumber(const std::string& str)
+{
+    size_t starting_location = 0;
+    if (str.size() > 2 && *str.begin() == '0' && *(str.begin()+1) == 'x') {
+        starting_location = 2;
+    }
+    for (const char c : str.substr(starting_location)) {
+        if (HexDigit(c) < 0) return false;
+    }
+    // Return false for empty string or "0x".
+    return (str.size() > starting_location);
+}
+
+std::vector<unsigned char> ParseHex(const char* psz)
+{
+    // convert hex dump to vector
+    std::vector<unsigned char> vch;
+    while (true)
+    {
+        while (IsSpace(*psz))
+            psz++;
+        signed char c = HexDigit(*psz++);
+        if (c == (signed char)-1)
+            break;
+        unsigned char n = (c << 4);
+        c = HexDigit(*psz++);
+        if (c == (signed char)-1)
+            break;
+        n |= c;
+        vch.push_back(n);
+    }
+    return vch;
+}
+
+std::vector<unsigned char> ParseHex(const std::string& str)
+{
+    return ParseHex(str.c_str());
+}
+
+void SplitHostPort(std::string in, int &portOut, std::string &hostOut) {
+    size_t colon = in.find_last_of(':');
+    // if a : is found, and it either follows a [...], or no other : is in the string, treat it as port separator
+    bool fHaveColon = colon != in.npos;
+    bool fBracketed = fHaveColon && (in[0]=='[' && in[colon-1]==']'); // if there is a colon, and in[0]=='[', colon is not 0, so in[colon-1] is safe
+    bool fMultiColon = fHaveColon && (in.find_last_of(':',colon-1) != in.npos);
+    if (fHaveColon && (colon==0 || fBracketed || !fMultiColon)) {
+        int32_t n;
+        if (ParseInt32(in.substr(colon + 1), &n) && n > 0 && n < 0x10000) {
+            in = in.substr(0, colon);
+            portOut = n;
+        }
+    }
+    if (in.size()>0 && in[0] == '[' && in[in.size()-1] == ']')
+        hostOut = in.substr(1, in.size()-2);
+    else
+        hostOut = in;
+}
+
+std::string EncodeBase64(const unsigned char* pch, size_t len)
+{
+    static const char *pbase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+    std::string str;
+    str.reserve(((len + 2) / 3) * 4);
+    ConvertBits<8, 6, true>([&](int v) { str += pbase64[v]; }, pch, pch + len);
+    while (str.size() % 4) str += '=';
+    return str;
+}
+
+std::string EncodeBase64(const std::string& str)
+{
+    return EncodeBase64((const unsigned char*)str.c_str(), str.size());
+}
+
+std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid)
+{
+    static const int decode64_table[256] =
+    {
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1,
+        -1, -1, -1, -1, -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
+        15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28,
+        29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,
+        49, 50, 51, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
+    };
+
+    const char* e = p;
+    std::vector<uint8_t> val;
+    val.reserve(strlen(p));
+    while (*p != 0) {
+        int x = decode64_table[(unsigned char)*p];
+        if (x == -1) break;
+        val.push_back(x);
+        ++p;
+    }
+
+    std::vector<unsigned char> ret;
+    ret.reserve((val.size() * 3) / 4);
+    bool valid = ConvertBits<6, 8, false>([&](unsigned char c) { ret.push_back(c); }, val.begin(), val.end());
+
+    const char* q = p;
+    while (valid && *p != 0) {
+        if (*p != '=') {
+            valid = false;
+            break;
+        }
+        ++p;
+    }
+    valid = valid && (p - e) % 4 == 0 && p - q < 4;
+    if (pfInvalid) *pfInvalid = !valid;
+
+    return ret;
+}
+
+std::string DecodeBase64(const std::string& str)
+{
+    std::vector<unsigned char> vchRet = DecodeBase64(str.c_str());
+    return std::string((const char*)vchRet.data(), vchRet.size());
+}
+
+std::string EncodeBase32(const unsigned char* pch, size_t len)
+{
+    static const char *pbase32 = "abcdefghijklmnopqrstuvwxyz234567";
+
+    std::string str;
+    str.reserve(((len + 4) / 5) * 8);
+    ConvertBits<8, 5, true>([&](int v) { str += pbase32[v]; }, pch, pch + len);
+    while (str.size() % 8) str += '=';
+    return str;
+}
+
+std::string EncodeBase32(const std::string& str)
+{
+    return EncodeBase32((const unsigned char*)str.c_str(), str.size());
+}
+
+std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid)
+{
+    static const int decode32_table[256] =
+    {
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
+        15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1,  0,  1,  2,
+         3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
+        23, 24, 25, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
+    };
+
+    const char* e = p;
+    std::vector<uint8_t> val;
+    val.reserve(strlen(p));
+    while (*p != 0) {
+        int x = decode32_table[(unsigned char)*p];
+        if (x == -1) break;
+        val.push_back(x);
+        ++p;
+    }
+
+    std::vector<unsigned char> ret;
+    ret.reserve((val.size() * 5) / 8);
+    bool valid = ConvertBits<5, 8, false>([&](unsigned char c) { ret.push_back(c); }, val.begin(), val.end());
+
+    const char* q = p;
+    while (valid && *p != 0) {
+        if (*p != '=') {
+            valid = false;
+            break;
+        }
+        ++p;
+    }
+    valid = valid && (p - e) % 8 == 0 && p - q < 8;
+    if (pfInvalid) *pfInvalid = !valid;
+
+    return ret;
+}
+
+std::string DecodeBase32(const std::string& str)
+{
+    std::vector<unsigned char> vchRet = DecodeBase32(str.c_str());
+    return std::string((const char*)vchRet.data(), vchRet.size());
+}
+
+static bool ParsePrechecks(const std::string& str)
+{
+    if (str.empty()) // No empty string allowed
+        return false;
+    if (str.size() >= 1 && (IsSpace(str[0]) || IsSpace(str[str.size()-1]))) // No padding allowed
+        return false;
+    if (str.size() != strlen(str.c_str())) // No embedded NUL characters allowed
+        return false;
+    return true;
+}
+
+bool ParseInt32(const std::string& str, int32_t *out)
+{
+    if (!ParsePrechecks(str))
+        return false;
+    char *endp = nullptr;
+    errno = 0; // strtol will not set errno if valid
+    long int n = strtol(str.c_str(), &endp, 10);
+    if(out) *out = (int32_t)n;
+    // Note that strtol returns a *long int*, so even if strtol doesn't report an over/underflow
+    // we still have to check that the returned value is within the range of an *int32_t*. On 64-bit
+    // platforms the size of these types may be different.
+    return endp && *endp == 0 && !errno &&
+        n >= std::numeric_limits<int32_t>::min() &&
+        n <= std::numeric_limits<int32_t>::max();
+}
+
+bool ParseInt64(const std::string& str, int64_t *out)
+{
+    if (!ParsePrechecks(str))
+        return false;
+    char *endp = nullptr;
+    errno = 0; // strtoll will not set errno if valid
+    long long int n = strtoll(str.c_str(), &endp, 10);
+    if(out) *out = (int64_t)n;
+    // Note that strtoll returns a *long long int*, so even if strtol doesn't report an over/underflow
+    // we still have to check that the returned value is within the range of an *int64_t*.
+    return endp && *endp == 0 && !errno &&
+        n >= std::numeric_limits<int64_t>::min() &&
+        n <= std::numeric_limits<int64_t>::max();
+}
+
+bool ParseUInt32(const std::string& str, uint32_t *out)
+{
+    if (!ParsePrechecks(str))
+        return false;
+    if (str.size() >= 1 && str[0] == '-') // Reject negative values, unfortunately strtoul accepts these by default if they fit in the range
+        return false;
+    char *endp = nullptr;
+    errno = 0; // strtoul will not set errno if valid
+    unsigned long int n = strtoul(str.c_str(), &endp, 10);
+    if(out) *out = (uint32_t)n;
+    // Note that strtoul returns a *unsigned long int*, so even if it doesn't report an over/underflow
+    // we still have to check that the returned value is within the range of an *uint32_t*. On 64-bit
+    // platforms the size of these types may be different.
+    return endp && *endp == 0 && !errno &&
+        n <= std::numeric_limits<uint32_t>::max();
+}
+
+bool ParseUInt64(const std::string& str, uint64_t *out)
+{
+    if (!ParsePrechecks(str))
+        return false;
+    if (str.size() >= 1 && str[0] == '-') // Reject negative values, unfortunately strtoull accepts these by default if they fit in the range
+        return false;
+    char *endp = nullptr;
+    errno = 0; // strtoull will not set errno if valid
+    unsigned long long int n = strtoull(str.c_str(), &endp, 10);
+    if(out) *out = (uint64_t)n;
+    // Note that strtoull returns a *unsigned long long int*, so even if it doesn't report an over/underflow
+    // we still have to check that the returned value is within the range of an *uint64_t*.
+    return endp && *endp == 0 && !errno &&
+        n <= std::numeric_limits<uint64_t>::max();
+}
+
+
+bool ParseDouble(const std::string& str, double *out)
+{
+    if (!ParsePrechecks(str))
+        return false;
+    if (str.size() >= 2 && str[0] == '0' && str[1] == 'x') // No hexadecimal floats allowed
+        return false;
+    std::istringstream text(str);
+    text.imbue(std::locale::classic());
+    double result;
+    text >> result;
+    if(out) *out = result;
+    return text.eof() && !text.fail();
+}
+
+std::string FormatParagraph(const std::string& in, size_t width, size_t indent)
+{
+    std::stringstream out;
+    size_t ptr = 0;
+    size_t indented = 0;
+    while (ptr < in.size())
+    {
+        size_t lineend = in.find_first_of('\n', ptr);
+        if (lineend == std::string::npos) {
+            lineend = in.size();
+        }
+        const size_t linelen = lineend - ptr;
+        const size_t rem_width = width - indented;
+        if (linelen <= rem_width) {
+            out << in.substr(ptr, linelen + 1);
+            ptr = lineend + 1;
+            indented = 0;
+        } else {
+            size_t finalspace = in.find_last_of(" \n", ptr + rem_width);
+            if (finalspace == std::string::npos || finalspace < ptr) {
+                // No place to break; just include the entire word and move on
+                finalspace = in.find_first_of("\n ", ptr);
+                if (finalspace == std::string::npos) {
+                    // End of the string, just add it and break
+                    out << in.substr(ptr);
+                    break;
+                }
+            }
+            out << in.substr(ptr, finalspace - ptr) << "\n";
+            if (in[finalspace] == '\n') {
+                indented = 0;
+            } else if (indent) {
+                out << std::string(indent, ' ');
+                indented = indent;
+            }
+            ptr = finalspace + 1;
+        }
+    }
+    return out.str();
+}
+
+std::string i64tostr(int64_t n)
+{
+    return strprintf("%d", n);
+}
+
+std::string itostr(int n)
+{
+    return strprintf("%d", n);
+}
+
+int64_t atoi64(const char* psz)
+{
+#ifdef _MSC_VER
+    return _atoi64(psz);
+#else
+    return strtoll(psz, nullptr, 10);
+#endif
+}
+
+int64_t atoi64(const std::string& str)
+{
+#ifdef _MSC_VER
+    return _atoi64(str.c_str());
+#else
+    return strtoll(str.c_str(), nullptr, 10);
+#endif
+}
+
+int atoi(const std::string& str)
+{
+    return atoi(str.c_str());
+}
+
+/** Upper bound for mantissa.
+ * 10^18-1 is the largest arbitrary decimal that will fit in a signed 64-bit integer.
+ * Larger integers cannot consist of arbitrary combinations of 0-9:
+ *
+ *   999999999999999999  1^18-1
+ *  9223372036854775807  (1<<63)-1  (max int64_t)
+ *  9999999999999999999  1^19-1     (would overflow)
+ */
+static const int64_t UPPER_BOUND = 1000000000000000000LL - 1LL;
+
+/** Helper function for ParseFixedPoint */
+static inline bool ProcessMantissaDigit(char ch, int64_t &mantissa, int &mantissa_tzeros)
+{
+    if(ch == '0')
+        ++mantissa_tzeros;
+    else {
+        for (int i=0; i<=mantissa_tzeros; ++i) {
+            if (mantissa > (UPPER_BOUND / 10LL))
+                return false; /* overflow */
+            mantissa *= 10;
+        }
+        mantissa += ch - '0';
+        mantissa_tzeros = 0;
+    }
+    return true;
+}
+
+bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out)
+{
+    int64_t mantissa = 0;
+    int64_t exponent = 0;
+    int mantissa_tzeros = 0;
+    bool mantissa_sign = false;
+    bool exponent_sign = false;
+    int ptr = 0;
+    int end = val.size();
+    int point_ofs = 0;
+
+    if (ptr < end && val[ptr] == '-') {
+        mantissa_sign = true;
+        ++ptr;
+    }
+    if (ptr < end)
+    {
+        if (val[ptr] == '0') {
+            /* pass single 0 */
+            ++ptr;
+        } else if (val[ptr] >= '1' && val[ptr] <= '9') {
+            while (ptr < end && IsDigit(val[ptr])) {
+                if (!ProcessMantissaDigit(val[ptr], mantissa, mantissa_tzeros))
+                    return false; /* overflow */
+                ++ptr;
+            }
+        } else return false; /* missing expected digit */
+    } else return false; /* empty string or loose '-' */
+    if (ptr < end && val[ptr] == '.')
+    {
+        ++ptr;
+        if (ptr < end && IsDigit(val[ptr]))
+        {
+            while (ptr < end && IsDigit(val[ptr])) {
+                if (!ProcessMantissaDigit(val[ptr], mantissa, mantissa_tzeros))
+                    return false; /* overflow */
+                ++ptr;
+                ++point_ofs;
+            }
+        } else return false; /* missing expected digit */
+    }
+    if (ptr < end && (val[ptr] == 'e' || val[ptr] == 'E'))
+    {
+        ++ptr;
+        if (ptr < end && val[ptr] == '+')
+            ++ptr;
+        else if (ptr < end && val[ptr] == '-') {
+            exponent_sign = true;
+            ++ptr;
+        }
+        if (ptr < end && IsDigit(val[ptr])) {
+            while (ptr < end && IsDigit(val[ptr])) {
+                if (exponent > (UPPER_BOUND / 10LL))
+                    return false; /* overflow */
+                exponent = exponent * 10 + val[ptr] - '0';
+                ++ptr;
+            }
+        } else return false; /* missing expected digit */
+    }
+    if (ptr != end)
+        return false; /* trailing garbage */
+
+    /* finalize exponent */
+    if (exponent_sign)
+        exponent = -exponent;
+    exponent = exponent - point_ofs + mantissa_tzeros;
+
+    /* finalize mantissa */
+    if (mantissa_sign)
+        mantissa = -mantissa;
+
+    /* convert to one 64-bit fixed-point value */
+    exponent += decimals;
+    if (exponent < 0)
+        return false; /* cannot represent values smaller than 10^-decimals */
+    if (exponent >= 18)
+        return false; /* cannot represent values larger than or equal to 10^(18-decimals) */
+
+    for (int i=0; i < exponent; ++i) {
+        if (mantissa > (UPPER_BOUND / 10LL) || mantissa < -(UPPER_BOUND / 10LL))
+            return false; /* overflow */
+        mantissa *= 10;
+    }
+    if (mantissa > UPPER_BOUND || mantissa < -UPPER_BOUND)
+        return false; /* overflow */
+
+    if (amount_out)
+        *amount_out = mantissa;
+
+    return true;
+}
+
+bool ParseHDKeypath(const std::string& keypath_str, std::vector<uint32_t>& keypath)
+{
+    std::stringstream ss(keypath_str);
+    std::string item;
+    bool first = true;
+    while (std::getline(ss, item, '/')) {
+        if (item.compare("m") == 0) {
+            if (first) {
+                first = false;
+                continue;
+            }
+            return false;
+        }
+        // Finds whether it is hardened
+        uint32_t path = 0;
+        size_t pos = item.find("'");
+        if (pos != std::string::npos) {
+            // The hardened tick can only be in the last index of the string
+            if (pos != item.size() - 1) {
+                return false;
+            }
+            path |= 0x80000000;
+            item = item.substr(0, item.size() - 1); // Drop the last character which is the hardened tick
+        }
+
+        // Ensure this is only numbers
+        if (item.find_first_not_of( "0123456789" ) != std::string::npos) {
+            return false;
+        }
+        uint32_t number;
+        if (!ParseUInt32(item, &number)) {
+            return false;
+        }
+        path |= number;
+
+        keypath.push_back(path);
+        first = false;
+    }
+    return true;
+}
+
+void Downcase(std::string& str)
+{
+    std::transform(str.begin(), str.end(), str.begin(), [](unsigned char c){return ToLower(c);});
+}
+
+std::string Capitalize(std::string str)
+{
+    if (str.empty()) return str;
+    str[0] = ToUpper(str.front());
+    return str;
+}
diff --git a/src/util/strencodings.h b/src/util/strencodings.h
new file mode 100644
index 0000000000..132071c61e
--- /dev/null
+++ b/src/util/strencodings.h
@@ -0,0 +1,248 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+/**
+ * Utilities for converting data from/to strings.
+ */
+#ifndef BITCOIN_UTIL_STRENCODINGS_H
+#define BITCOIN_UTIL_STRENCODINGS_H
+
+#include <stdint.h>
+#include <string>
+#include <vector>
+
+#define BEGIN(a)            ((char*)&(a))
+#define END(a)              ((char*)&((&(a))[1]))
+#define UBEGIN(a)           ((unsigned char*)&(a))
+#define UEND(a)             ((unsigned char*)&((&(a))[1]))
+#define ARRAYLEN(array)     (sizeof(array)/sizeof((array)[0]))
+
+/** Used by SanitizeString() */
+enum SafeChars
+{
+    SAFE_CHARS_DEFAULT, //!< The full set of allowed chars
+    SAFE_CHARS_UA_COMMENT, //!< BIP-0014 subset
+    SAFE_CHARS_FILENAME, //!< Chars allowed in filenames
+};
+
+/**
+* Remove unsafe chars. Safe chars chosen to allow simple messages/URLs/email
+* addresses, but avoid anything even possibly remotely dangerous like & or >
+* @param[in] str    The string to sanitize
+* @param[in] rule   The set of safe chars to choose (default: least restrictive)
+* @return           A new string without unsafe chars
+*/
+std::string SanitizeString(const std::string& str, int rule = SAFE_CHARS_DEFAULT);
+std::vector<unsigned char> ParseHex(const char* psz);
+std::vector<unsigned char> ParseHex(const std::string& str);
+signed char HexDigit(char c);
+/* Returns true if each character in str is a hex character, and has an even
+ * number of hex digits.*/
+bool IsHex(const std::string& str);
+/**
+* Return true if the string is a hex number, optionally prefixed with "0x"
+*/
+bool IsHexNumber(const std::string& str);
+std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid = nullptr);
+std::string DecodeBase64(const std::string& str);
+std::string EncodeBase64(const unsigned char* pch, size_t len);
+std::string EncodeBase64(const std::string& str);
+std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid = nullptr);
+std::string DecodeBase32(const std::string& str);
+std::string EncodeBase32(const unsigned char* pch, size_t len);
+std::string EncodeBase32(const std::string& str);
+
+void SplitHostPort(std::string in, int &portOut, std::string &hostOut);
+std::string i64tostr(int64_t n);
+std::string itostr(int n);
+int64_t atoi64(const char* psz);
+int64_t atoi64(const std::string& str);
+int atoi(const std::string& str);
+
+/**
+ * Tests if the given character is a decimal digit.
+ * @param[in] c     character to test
+ * @return          true if the argument is a decimal digit; otherwise false.
+ */
+constexpr bool IsDigit(char c)
+{
+    return c >= '0' && c <= '9';
+}
+
+/**
+ * Tests if the given character is a whitespace character. The whitespace characters
+ * are: space, form-feed ('\f'), newline ('\n'), carriage return ('\r'), horizontal
+ * tab ('\t'), and vertical tab ('\v').
+ *
+ * This function is locale independent. Under the C locale this function gives the
+ * same result as std::isspace.
+ *
+ * @param[in] c     character to test
+ * @return          true if the argument is a whitespace character; otherwise false
+ */
+constexpr inline bool IsSpace(char c) noexcept {
+    return c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v';
+}
+
+/**
+ * Convert string to signed 32-bit integer with strict parse error feedback.
+ * @returns true if the entire string could be parsed as valid integer,
+ *   false if not the entire string could be parsed or when overflow or underflow occurred.
+ */
+bool ParseInt32(const std::string& str, int32_t *out);
+
+/**
+ * Convert string to signed 64-bit integer with strict parse error feedback.
+ * @returns true if the entire string could be parsed as valid integer,
+ *   false if not the entire string could be parsed or when overflow or underflow occurred.
+ */
+bool ParseInt64(const std::string& str, int64_t *out);
+
+/**
+ * Convert decimal string to unsigned 32-bit integer with strict parse error feedback.
+ * @returns true if the entire string could be parsed as valid integer,
+ *   false if not the entire string could be parsed or when overflow or underflow occurred.
+ */
+bool ParseUInt32(const std::string& str, uint32_t *out);
+
+/**
+ * Convert decimal string to unsigned 64-bit integer with strict parse error feedback.
+ * @returns true if the entire string could be parsed as valid integer,
+ *   false if not the entire string could be parsed or when overflow or underflow occurred.
+ */
+bool ParseUInt64(const std::string& str, uint64_t *out);
+
+/**
+ * Convert string to double with strict parse error feedback.
+ * @returns true if the entire string could be parsed as valid double,
+ *   false if not the entire string could be parsed or when overflow or underflow occurred.
+ */
+bool ParseDouble(const std::string& str, double *out);
+
+template<typename T>
+std::string HexStr(const T itbegin, const T itend, bool fSpaces=false)
+{
+    std::string rv;
+    static const char hexmap[16] = { '0', '1', '2', '3', '4', '5', '6', '7',
+                                     '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
+    rv.reserve((itend-itbegin)*3);
+    for(T it = itbegin; it < itend; ++it)
+    {
+        unsigned char val = (unsigned char)(*it);
+        if(fSpaces && it != itbegin)
+            rv.push_back(' ');
+        rv.push_back(hexmap[val>>4]);
+        rv.push_back(hexmap[val&15]);
+    }
+
+    return rv;
+}
+
+template<typename T>
+inline std::string HexStr(const T& vch, bool fSpaces=false)
+{
+    return HexStr(vch.begin(), vch.end(), fSpaces);
+}
+
+/**
+ * Format a paragraph of text to a fixed width, adding spaces for
+ * indentation to any added line.
+ */
+std::string FormatParagraph(const std::string& in, size_t width = 79, size_t indent = 0);
+
+/**
+ * Timing-attack-resistant comparison.
+ * Takes time proportional to length
+ * of first argument.
+ */
+template <typename T>
+bool TimingResistantEqual(const T& a, const T& b)
+{
+    if (b.size() == 0) return a.size() == 0;
+    size_t accumulator = a.size() ^ b.size();
+    for (size_t i = 0; i < a.size(); i++)
+        accumulator |= a[i] ^ b[i%b.size()];
+    return accumulator == 0;
+}
+
+/** Parse number as fixed point according to JSON number syntax.
+ * See http://json.org/number.gif
+ * @returns true on success, false on error.
+ * @note The result must be in the range (-10^18,10^18), otherwise an overflow error will trigger.
+ */
+bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out);
+
+/** Convert from one power-of-2 number base to another. */
+template<int frombits, int tobits, bool pad, typename O, typename I>
+bool ConvertBits(const O& outfn, I it, I end) {
+    size_t acc = 0;
+    size_t bits = 0;
+    constexpr size_t maxv = (1 << tobits) - 1;
+    constexpr size_t max_acc = (1 << (frombits + tobits - 1)) - 1;
+    while (it != end) {
+        acc = ((acc << frombits) | *it) & max_acc;
+        bits += frombits;
+        while (bits >= tobits) {
+            bits -= tobits;
+            outfn((acc >> bits) & maxv);
+        }
+        ++it;
+    }
+    if (pad) {
+        if (bits) outfn((acc << (tobits - bits)) & maxv);
+    } else if (bits >= frombits || ((acc << (tobits - bits)) & maxv)) {
+        return false;
+    }
+    return true;
+}
+
+/** Parse an HD keypaths like "m/7/0'/2000". */
+bool ParseHDKeypath(const std::string& keypath_str, std::vector<uint32_t>& keypath);
+
+/**
+ * Converts the given character to its lowercase equivalent.
+ * This function is locale independent. It only converts uppercase
+ * characters in the standard 7-bit ASCII range.
+ * @param[in] c     the character to convert to lowercase.
+ * @return          the lowercase equivalent of c; or the argument
+ *                  if no conversion is possible.
+ */
+constexpr unsigned char ToLower(unsigned char c)
+{
+    return (c >= 'A' && c <= 'Z' ? (c - 'A') + 'a' : c);
+}
+
+/**
+ * Converts the given string to its lowercase equivalent.
+ * This function is locale independent. It only converts uppercase
+ * characters in the standard 7-bit ASCII range.
+ * @param[in,out] str   the string to convert to lowercase.
+ */
+void Downcase(std::string& str);
+
+/**
+ * Converts the given character to its uppercase equivalent.
+ * This function is locale independent. It only converts lowercase
+ * characters in the standard 7-bit ASCII range.
+ * @param[in] c     the character to convert to uppercase.
+ * @return          the uppercase equivalent of c; or the argument
+ *                  if no conversion is possible.
+ */
+constexpr unsigned char ToUpper(unsigned char c)
+{
+    return (c >= 'a' && c <= 'z' ? (c - 'a') + 'A' : c);
+}
+
+/**
+ * Capitalizes the first character of the given string.
+ * This function is locale independent. It only capitalizes the
+ * first character of the argument if it has an uppercase equivalent
+ * in the standard 7-bit ASCII range.
+ * @param[in] str   the string to capitalize.
+ * @return          string with the first letter capitalized.
+ */
+std::string Capitalize(std::string str);
+
+#endif // BITCOIN_UTIL_STRENCODINGS_H
diff --git a/src/util/system.cpp b/src/util/system.cpp
new file mode 100644
index 0000000000..4f5dd2d6e9
--- /dev/null
+++ b/src/util/system.cpp
@@ -0,0 +1,1299 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <util/system.h>
+
+#include <chainparamsbase.h>
+#include <random.h>
+#include <serialize.h>
+#include <util/strencodings.h>
+
+#include <stdarg.h>
+
+#if (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
+#include <pthread.h>
+#include <pthread_np.h>
+#endif
+
+#ifndef WIN32
+// for posix_fallocate
+#ifdef __linux__
+
+#ifdef _POSIX_C_SOURCE
+#undef _POSIX_C_SOURCE
+#endif
+
+#define _POSIX_C_SOURCE 200112L
+
+#endif // __linux__
+
+#include <algorithm>
+#include <fcntl.h>
+#include <sched.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+
+#else
+
+#ifdef _MSC_VER
+#pragma warning(disable:4786)
+#pragma warning(disable:4804)
+#pragma warning(disable:4805)
+#pragma warning(disable:4717)
+#endif
+
+#ifdef _WIN32_WINNT
+#undef _WIN32_WINNT
+#endif
+#define _WIN32_WINNT 0x0501
+
+#ifdef _WIN32_IE
+#undef _WIN32_IE
+#endif
+#define _WIN32_IE 0x0501
+
+#define WIN32_LEAN_AND_MEAN 1
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif
+#include <codecvt>
+
+#include <io.h> /* for _commit */
+#include <shellapi.h>
+#include <shlobj.h>
+#endif
+
+#ifdef HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#endif
+
+#ifdef HAVE_MALLOPT_ARENA_MAX
+#include <malloc.h>
+#endif
+
+#include <boost/thread.hpp>
+#include <openssl/crypto.h>
+#include <openssl/rand.h>
+#include <openssl/conf.h>
+#include <thread>
+
+// Application startup time (used for uptime calculation)
+const int64_t nStartupTime = GetTime();
+
+const char * const BITCOIN_CONF_FILENAME = "bitcoin.conf";
+const char * const BITCOIN_PID_FILENAME = "bitcoind.pid";
+
+ArgsManager gArgs;
+
+/** Init OpenSSL library multithreading support */
+static std::unique_ptr<CCriticalSection[]> ppmutexOpenSSL;
+void locking_callback(int mode, int i, const char* file, int line) NO_THREAD_SAFETY_ANALYSIS
+{
+    if (mode & CRYPTO_LOCK) {
+        ENTER_CRITICAL_SECTION(ppmutexOpenSSL[i]);
+    } else {
+        LEAVE_CRITICAL_SECTION(ppmutexOpenSSL[i]);
+    }
+}
+
+// Singleton for wrapping OpenSSL setup/teardown.
+class CInit
+{
+public:
+    CInit()
+    {
+        // Init OpenSSL library multithreading support
+        ppmutexOpenSSL.reset(new CCriticalSection[CRYPTO_num_locks()]);
+        CRYPTO_set_locking_callback(locking_callback);
+
+        // OpenSSL can optionally load a config file which lists optional loadable modules and engines.
+        // We don't use them so we don't require the config. However some of our libs may call functions
+        // which attempt to load the config file, possibly resulting in an exit() or crash if it is missing
+        // or corrupt. Explicitly tell OpenSSL not to try to load the file. The result for our libs will be
+        // that the config appears to have been loaded and there are no modules/engines available.
+        OPENSSL_no_config();
+
+#ifdef WIN32
+        // Seed OpenSSL PRNG with current contents of the screen
+        RAND_screen();
+#endif
+
+        // Seed OpenSSL PRNG with performance counter
+        RandAddSeed();
+    }
+    ~CInit()
+    {
+        // Securely erase the memory used by the PRNG
+        RAND_cleanup();
+        // Shutdown OpenSSL library multithreading support
+        CRYPTO_set_locking_callback(nullptr);
+        // Clear the set of locks now to maintain symmetry with the constructor.
+        ppmutexOpenSSL.reset();
+    }
+}
+instance_of_cinit;
+
+/** A map that contains all the currently held directory locks. After
+ * successful locking, these will be held here until the global destructor
+ * cleans them up and thus automatically unlocks them, or ReleaseDirectoryLocks
+ * is called.
+ */
+static std::map<std::string, std::unique_ptr<fsbridge::FileLock>> dir_locks;
+/** Mutex to protect dir_locks. */
+static std::mutex cs_dir_locks;
+
+bool LockDirectory(const fs::path& directory, const std::string lockfile_name, bool probe_only)
+{
+    std::lock_guard<std::mutex> ulock(cs_dir_locks);
+    fs::path pathLockFile = directory / lockfile_name;
+
+    // If a lock for this directory already exists in the map, don't try to re-lock it
+    if (dir_locks.count(pathLockFile.string())) {
+        return true;
+    }
+
+    // Create empty lock file if it doesn't exist.
+    FILE* file = fsbridge::fopen(pathLockFile, "a");
+    if (file) fclose(file);
+    auto lock = MakeUnique<fsbridge::FileLock>(pathLockFile);
+    if (!lock->TryLock()) {
+        return error("Error while attempting to lock directory %s: %s", directory.string(), lock->GetReason());
+    }
+    if (!probe_only) {
+        // Lock successful and we're not just probing, put it into the map
+        dir_locks.emplace(pathLockFile.string(), std::move(lock));
+    }
+    return true;
+}
+
+void ReleaseDirectoryLocks()
+{
+    std::lock_guard<std::mutex> ulock(cs_dir_locks);
+    dir_locks.clear();
+}
+
+bool DirIsWritable(const fs::path& directory)
+{
+    fs::path tmpFile = directory / fs::unique_path();
+
+    FILE* file = fsbridge::fopen(tmpFile, "a");
+    if (!file) return false;
+
+    fclose(file);
+    remove(tmpFile);
+
+    return true;
+}
+
+/**
+ * Interpret a string argument as a boolean.
+ *
+ * The definition of atoi() requires that non-numeric string values like "foo",
+ * return 0. This means that if a user unintentionally supplies a non-integer
+ * argument here, the return value is always false. This means that -foo=false
+ * does what the user probably expects, but -foo=true is well defined but does
+ * not do what they probably expected.
+ *
+ * The return value of atoi() is undefined when given input not representable as
+ * an int. On most systems this means string value between "-2147483648" and
+ * "2147483647" are well defined (this method will return true). Setting
+ * -txindex=2147483648 on most systems, however, is probably undefined.
+ *
+ * For a more extensive discussion of this topic (and a wide range of opinions
+ * on the Right Way to change this code), see PR12713.
+ */
+static bool InterpretBool(const std::string& strValue)
+{
+    if (strValue.empty())
+        return true;
+    return (atoi(strValue) != 0);
+}
+
+/** Internal helper functions for ArgsManager */
+class ArgsManagerHelper {
+public:
+    typedef std::map<std::string, std::vector<std::string>> MapArgs;
+
+    /** Determine whether to use config settings in the default section,
+     *  See also comments around ArgsManager::ArgsManager() below. */
+    static inline bool UseDefaultSection(const ArgsManager& am, const std::string& arg) EXCLUSIVE_LOCKS_REQUIRED(am.cs_args)
+    {
+        return (am.m_network == CBaseChainParams::MAIN || am.m_network_only_args.count(arg) == 0);
+    }
+
+    /** Convert regular argument into the network-specific setting */
+    static inline std::string NetworkArg(const ArgsManager& am, const std::string& arg)
+    {
+        assert(arg.length() > 1 && arg[0] == '-');
+        return "-" + am.m_network + "." + arg.substr(1);
+    }
+
+    /** Find arguments in a map and add them to a vector */
+    static inline void AddArgs(std::vector<std::string>& res, const MapArgs& map_args, const std::string& arg)
+    {
+        auto it = map_args.find(arg);
+        if (it != map_args.end()) {
+            res.insert(res.end(), it->second.begin(), it->second.end());
+        }
+    }
+
+    /** Return true/false if an argument is set in a map, and also
+     *  return the first (or last) of the possibly multiple values it has
+     */
+    static inline std::pair<bool,std::string> GetArgHelper(const MapArgs& map_args, const std::string& arg, bool getLast = false)
+    {
+        auto it = map_args.find(arg);
+
+        if (it == map_args.end() || it->second.empty()) {
+            return std::make_pair(false, std::string());
+        }
+
+        if (getLast) {
+            return std::make_pair(true, it->second.back());
+        } else {
+            return std::make_pair(true, it->second.front());
+        }
+    }
+
+    /* Get the string value of an argument, returning a pair of a boolean
+     * indicating the argument was found, and the value for the argument
+     * if it was found (or the empty string if not found).
+     */
+    static inline std::pair<bool,std::string> GetArg(const ArgsManager &am, const std::string& arg)
+    {
+        LOCK(am.cs_args);
+        std::pair<bool,std::string> found_result(false, std::string());
+
+        // We pass "true" to GetArgHelper in order to return the last
+        // argument value seen from the command line (so "bitcoind -foo=bar
+        // -foo=baz" gives GetArg(am,"foo")=={true,"baz"}
+        found_result = GetArgHelper(am.m_override_args, arg, true);
+        if (found_result.first) {
+            return found_result;
+        }
+
+        // But in contrast we return the first argument seen in a config file,
+        // so "foo=bar \n foo=baz" in the config file gives
+        // GetArg(am,"foo")={true,"bar"}
+        if (!am.m_network.empty()) {
+            found_result = GetArgHelper(am.m_config_args, NetworkArg(am, arg));
+            if (found_result.first) {
+                return found_result;
+            }
+        }
+
+        if (UseDefaultSection(am, arg)) {
+            found_result = GetArgHelper(am.m_config_args, arg);
+            if (found_result.first) {
+                return found_result;
+            }
+        }
+
+        return found_result;
+    }
+
+    /* Special test for -testnet and -regtest args, because we
+     * don't want to be confused by craziness like "[regtest] testnet=1"
+     */
+    static inline bool GetNetBoolArg(const ArgsManager &am, const std::string& net_arg) EXCLUSIVE_LOCKS_REQUIRED(am.cs_args)
+    {
+        std::pair<bool,std::string> found_result(false,std::string());
+        found_result = GetArgHelper(am.m_override_args, net_arg, true);
+        if (!found_result.first) {
+            found_result = GetArgHelper(am.m_config_args, net_arg, true);
+            if (!found_result.first) {
+                return false; // not set
+            }
+        }
+        return InterpretBool(found_result.second); // is set, so evaluate
+    }
+};
+
+/**
+ * Interpret -nofoo as if the user supplied -foo=0.
+ *
+ * This method also tracks when the -no form was supplied, and if so,
+ * checks whether there was a double-negative (-nofoo=0 -> -foo=1).
+ *
+ * If there was not a double negative, it removes the "no" from the key,
+ * and returns true, indicating the caller should clear the args vector
+ * to indicate a negated option.
+ *
+ * If there was a double negative, it removes "no" from the key, sets the
+ * value to "1" and returns false.
+ *
+ * If there was no "no", it leaves key and value untouched and returns
+ * false.
+ *
+ * Where an option was negated can be later checked using the
+ * IsArgNegated() method. One use case for this is to have a way to disable
+ * options that are not normally boolean (e.g. using -nodebuglogfile to request
+ * that debug log output is not sent to any file at all).
+ */
+static bool InterpretNegatedOption(std::string& key, std::string& val)
+{
+    assert(key[0] == '-');
+
+    size_t option_index = key.find('.');
+    if (option_index == std::string::npos) {
+        option_index = 1;
+    } else {
+        ++option_index;
+    }
+    if (key.substr(option_index, 2) == "no") {
+        bool bool_val = InterpretBool(val);
+        key.erase(option_index, 2);
+        if (!bool_val ) {
+            // Double negatives like -nofoo=0 are supported (but discouraged)
+            LogPrintf("Warning: parsed potentially confusing double-negative %s=%s\n", key, val);
+            val = "1";
+        } else {
+            return true;
+        }
+    }
+    return false;
+}
+
+ArgsManager::ArgsManager() :
+    /* These options would cause cross-contamination if values for
+     * mainnet were used while running on regtest/testnet (or vice-versa).
+     * Setting them as section_only_args ensures that sharing a config file
+     * between mainnet and regtest/testnet won't cause problems due to these
+     * parameters by accident. */
+    m_network_only_args{
+      "-addnode", "-connect",
+      "-port", "-bind",
+      "-rpcport", "-rpcbind",
+      "-wallet",
+    }
+{
+    // nothing to do
+}
+
+void ArgsManager::WarnForSectionOnlyArgs()
+{
+    LOCK(cs_args);
+
+    // if there's no section selected, don't worry
+    if (m_network.empty()) return;
+
+    // if it's okay to use the default section for this network, don't worry
+    if (m_network == CBaseChainParams::MAIN) return;
+
+    for (const auto& arg : m_network_only_args) {
+        std::pair<bool, std::string> found_result;
+
+        // if this option is overridden it's fine
+        found_result = ArgsManagerHelper::GetArgHelper(m_override_args, arg);
+        if (found_result.first) continue;
+
+        // if there's a network-specific value for this option, it's fine
+        found_result = ArgsManagerHelper::GetArgHelper(m_config_args, ArgsManagerHelper::NetworkArg(*this, arg));
+        if (found_result.first) continue;
+
+        // if there isn't a default value for this option, it's fine
+        found_result = ArgsManagerHelper::GetArgHelper(m_config_args, arg);
+        if (!found_result.first) continue;
+
+        // otherwise, issue a warning
+        LogPrintf("Warning: Config setting for %s only applied on %s network when in [%s] section.\n", arg, m_network, m_network);
+    }
+}
+
+void ArgsManager::SelectConfigNetwork(const std::string& network)
+{
+    LOCK(cs_args);
+    m_network = network;
+}
+
+bool ArgsManager::ParseParameters(int argc, const char* const argv[], std::string& error)
+{
+    LOCK(cs_args);
+    m_override_args.clear();
+
+    for (int i = 1; i < argc; i++) {
+        std::string key(argv[i]);
+        std::string val;
+        size_t is_index = key.find('=');
+        if (is_index != std::string::npos) {
+            val = key.substr(is_index + 1);
+            key.erase(is_index);
+        }
+#ifdef WIN32
+        std::transform(key.begin(), key.end(), key.begin(), ::tolower);
+        if (key[0] == '/')
+            key[0] = '-';
+#endif
+
+        if (key[0] != '-')
+            break;
+
+        // Transform --foo to -foo
+        if (key.length() > 1 && key[1] == '-')
+            key.erase(0, 1);
+
+        // Check for -nofoo
+        if (InterpretNegatedOption(key, val)) {
+            m_override_args[key].clear();
+        } else {
+            m_override_args[key].push_back(val);
+        }
+
+        // Check that the arg is known
+        if (!(IsSwitchChar(key[0]) && key.size() == 1)) {
+            if (!IsArgKnown(key)) {
+                error = strprintf("Invalid parameter %s", key.c_str());
+                return false;
+            }
+        }
+    }
+
+    // we do not allow -includeconf from command line, so we clear it here
+    auto it = m_override_args.find("-includeconf");
+    if (it != m_override_args.end()) {
+        if (it->second.size() > 0) {
+            for (const auto& ic : it->second) {
+                error += "-includeconf cannot be used from commandline; -includeconf=" + ic + "\n";
+            }
+            return false;
+        }
+    }
+    return true;
+}
+
+bool ArgsManager::IsArgKnown(const std::string& key) const
+{
+    size_t option_index = key.find('.');
+    std::string arg_no_net;
+    if (option_index == std::string::npos) {
+        arg_no_net = key;
+    } else {
+        arg_no_net = std::string("-") + key.substr(option_index + 1, std::string::npos);
+    }
+
+    LOCK(cs_args);
+    for (const auto& arg_map : m_available_args) {
+        if (arg_map.second.count(arg_no_net)) return true;
+    }
+    return false;
+}
+
+std::vector<std::string> ArgsManager::GetArgs(const std::string& strArg) const
+{
+    std::vector<std::string> result = {};
+    if (IsArgNegated(strArg)) return result; // special case
+
+    LOCK(cs_args);
+
+    ArgsManagerHelper::AddArgs(result, m_override_args, strArg);
+    if (!m_network.empty()) {
+        ArgsManagerHelper::AddArgs(result, m_config_args, ArgsManagerHelper::NetworkArg(*this, strArg));
+    }
+
+    if (ArgsManagerHelper::UseDefaultSection(*this, strArg)) {
+        ArgsManagerHelper::AddArgs(result, m_config_args, strArg);
+    }
+
+    return result;
+}
+
+bool ArgsManager::IsArgSet(const std::string& strArg) const
+{
+    if (IsArgNegated(strArg)) return true; // special case
+    return ArgsManagerHelper::GetArg(*this, strArg).first;
+}
+
+bool ArgsManager::IsArgNegated(const std::string& strArg) const
+{
+    LOCK(cs_args);
+
+    const auto& ov = m_override_args.find(strArg);
+    if (ov != m_override_args.end()) return ov->second.empty();
+
+    if (!m_network.empty()) {
+        const auto& cfs = m_config_args.find(ArgsManagerHelper::NetworkArg(*this, strArg));
+        if (cfs != m_config_args.end()) return cfs->second.empty();
+    }
+
+    const auto& cf = m_config_args.find(strArg);
+    if (cf != m_config_args.end()) return cf->second.empty();
+
+    return false;
+}
+
+std::string ArgsManager::GetArg(const std::string& strArg, const std::string& strDefault) const
+{
+    if (IsArgNegated(strArg)) return "0";
+    std::pair<bool,std::string> found_res = ArgsManagerHelper::GetArg(*this, strArg);
+    if (found_res.first) return found_res.second;
+    return strDefault;
+}
+
+int64_t ArgsManager::GetArg(const std::string& strArg, int64_t nDefault) const
+{
+    if (IsArgNegated(strArg)) return 0;
+    std::pair<bool,std::string> found_res = ArgsManagerHelper::GetArg(*this, strArg);
+    if (found_res.first) return atoi64(found_res.second);
+    return nDefault;
+}
+
+bool ArgsManager::GetBoolArg(const std::string& strArg, bool fDefault) const
+{
+    if (IsArgNegated(strArg)) return false;
+    std::pair<bool,std::string> found_res = ArgsManagerHelper::GetArg(*this, strArg);
+    if (found_res.first) return InterpretBool(found_res.second);
+    return fDefault;
+}
+
+bool ArgsManager::SoftSetArg(const std::string& strArg, const std::string& strValue)
+{
+    LOCK(cs_args);
+    if (IsArgSet(strArg)) return false;
+    ForceSetArg(strArg, strValue);
+    return true;
+}
+
+bool ArgsManager::SoftSetBoolArg(const std::string& strArg, bool fValue)
+{
+    if (fValue)
+        return SoftSetArg(strArg, std::string("1"));
+    else
+        return SoftSetArg(strArg, std::string("0"));
+}
+
+void ArgsManager::ForceSetArg(const std::string& strArg, const std::string& strValue)
+{
+    LOCK(cs_args);
+    m_override_args[strArg] = {strValue};
+}
+
+void ArgsManager::AddArg(const std::string& name, const std::string& help, const bool debug_only, const OptionsCategory& cat)
+{
+    // Split arg name from its help param
+    size_t eq_index = name.find('=');
+    if (eq_index == std::string::npos) {
+        eq_index = name.size();
+    }
+
+    LOCK(cs_args);
+    std::map<std::string, Arg>& arg_map = m_available_args[cat];
+    auto ret = arg_map.emplace(name.substr(0, eq_index), Arg(name.substr(eq_index, name.size() - eq_index), help, debug_only));
+    assert(ret.second); // Make sure an insertion actually happened
+}
+
+void ArgsManager::AddHiddenArgs(const std::vector<std::string>& names)
+{
+    for (const std::string& name : names) {
+        AddArg(name, "", false, OptionsCategory::HIDDEN);
+    }
+}
+
+std::string ArgsManager::GetHelpMessage() const
+{
+    const bool show_debug = gArgs.GetBoolArg("-help-debug", false);
+
+    std::string usage = "";
+    LOCK(cs_args);
+    for (const auto& arg_map : m_available_args) {
+        switch(arg_map.first) {
+            case OptionsCategory::OPTIONS:
+                usage += HelpMessageGroup("Options:");
+                break;
+            case OptionsCategory::CONNECTION:
+                usage += HelpMessageGroup("Connection options:");
+                break;
+            case OptionsCategory::ZMQ:
+                usage += HelpMessageGroup("ZeroMQ notification options:");
+                break;
+            case OptionsCategory::DEBUG_TEST:
+                usage += HelpMessageGroup("Debugging/Testing options:");
+                break;
+            case OptionsCategory::NODE_RELAY:
+                usage += HelpMessageGroup("Node relay options:");
+                break;
+            case OptionsCategory::BLOCK_CREATION:
+                usage += HelpMessageGroup("Block creation options:");
+                break;
+            case OptionsCategory::RPC:
+                usage += HelpMessageGroup("RPC server options:");
+                break;
+            case OptionsCategory::WALLET:
+                usage += HelpMessageGroup("Wallet options:");
+                break;
+            case OptionsCategory::WALLET_DEBUG_TEST:
+                if (show_debug) usage += HelpMessageGroup("Wallet debugging/testing options:");
+                break;
+            case OptionsCategory::CHAINPARAMS:
+                usage += HelpMessageGroup("Chain selection options:");
+                break;
+            case OptionsCategory::GUI:
+                usage += HelpMessageGroup("UI Options:");
+                break;
+            case OptionsCategory::COMMANDS:
+                usage += HelpMessageGroup("Commands:");
+                break;
+            case OptionsCategory::REGISTER_COMMANDS:
+                usage += HelpMessageGroup("Register Commands:");
+                break;
+            default:
+                break;
+        }
+
+        // When we get to the hidden options, stop
+        if (arg_map.first == OptionsCategory::HIDDEN) break;
+
+        for (const auto& arg : arg_map.second) {
+            if (show_debug || !arg.second.m_debug_only) {
+                std::string name;
+                if (arg.second.m_help_param.empty()) {
+                    name = arg.first;
+                } else {
+                    name = arg.first + arg.second.m_help_param;
+                }
+                usage += HelpMessageOpt(name, arg.second.m_help_text);
+            }
+        }
+    }
+    return usage;
+}
+
+bool HelpRequested(const ArgsManager& args)
+{
+    return args.IsArgSet("-?") || args.IsArgSet("-h") || args.IsArgSet("-help") || args.IsArgSet("-help-debug");
+}
+
+static const int screenWidth = 79;
+static const int optIndent = 2;
+static const int msgIndent = 7;
+
+std::string HelpMessageGroup(const std::string &message) {
+    return std::string(message) + std::string("\n\n");
+}
+
+std::string HelpMessageOpt(const std::string &option, const std::string &message) {
+    return std::string(optIndent,' ') + std::string(option) +
+           std::string("\n") + std::string(msgIndent,' ') +
+           FormatParagraph(message, screenWidth - msgIndent, msgIndent) +
+           std::string("\n\n");
+}
+
+static std::string FormatException(const std::exception* pex, const char* pszThread)
+{
+#ifdef WIN32
+    char pszModule[MAX_PATH] = "";
+    GetModuleFileNameA(nullptr, pszModule, sizeof(pszModule));
+#else
+    const char* pszModule = "bitcoin";
+#endif
+    if (pex)
+        return strprintf(
+            "EXCEPTION: %s       \n%s       \n%s in %s       \n", typeid(*pex).name(), pex->what(), pszModule, pszThread);
+    else
+        return strprintf(
+            "UNKNOWN EXCEPTION       \n%s in %s       \n", pszModule, pszThread);
+}
+
+void PrintExceptionContinue(const std::exception* pex, const char* pszThread)
+{
+    std::string message = FormatException(pex, pszThread);
+    LogPrintf("\n\n************************\n%s\n", message);
+    fprintf(stderr, "\n\n************************\n%s\n", message.c_str());
+}
+
+fs::path GetDefaultDataDir()
+{
+    // Windows < Vista: C:\Documents and Settings\Username\Application Data\Bitcoin
+    // Windows >= Vista: C:\Users\Username\AppData\Roaming\Bitcoin
+    // Mac: ~/Library/Application Support/Bitcoin
+    // Unix: ~/.bitcoin
+#ifdef WIN32
+    // Windows
+    return GetSpecialFolderPath(CSIDL_APPDATA) / "Bitcoin";
+#else
+    fs::path pathRet;
+    char* pszHome = getenv("HOME");
+    if (pszHome == nullptr || strlen(pszHome) == 0)
+        pathRet = fs::path("/");
+    else
+        pathRet = fs::path(pszHome);
+#ifdef MAC_OSX
+    // Mac
+    return pathRet / "Library/Application Support/Bitcoin";
+#else
+    // Unix
+    return pathRet / ".bitcoin";
+#endif
+#endif
+}
+
+static fs::path g_blocks_path_cached;
+static fs::path g_blocks_path_cache_net_specific;
+static fs::path pathCached;
+static fs::path pathCachedNetSpecific;
+static CCriticalSection csPathCached;
+
+const fs::path &GetBlocksDir(bool fNetSpecific)
+{
+
+    LOCK(csPathCached);
+
+    fs::path &path = fNetSpecific ? g_blocks_path_cache_net_specific : g_blocks_path_cached;
+
+    // This can be called during exceptions by LogPrintf(), so we cache the
+    // value so we don't have to do memory allocations after that.
+    if (!path.empty())
+        return path;
+
+    if (gArgs.IsArgSet("-blocksdir")) {
+        path = fs::system_complete(gArgs.GetArg("-blocksdir", ""));
+        if (!fs::is_directory(path)) {
+            path = "";
+            return path;
+        }
+    } else {
+        path = GetDataDir(false);
+    }
+    if (fNetSpecific)
+        path /= BaseParams().DataDir();
+
+    path /= "blocks";
+    fs::create_directories(path);
+    return path;
+}
+
+const fs::path &GetDataDir(bool fNetSpecific)
+{
+
+    LOCK(csPathCached);
+
+    fs::path &path = fNetSpecific ? pathCachedNetSpecific : pathCached;
+
+    // This can be called during exceptions by LogPrintf(), so we cache the
+    // value so we don't have to do memory allocations after that.
+    if (!path.empty())
+        return path;
+
+    if (gArgs.IsArgSet("-datadir")) {
+        path = fs::system_complete(gArgs.GetArg("-datadir", ""));
+        if (!fs::is_directory(path)) {
+            path = "";
+            return path;
+        }
+    } else {
+        path = GetDefaultDataDir();
+    }
+    if (fNetSpecific)
+        path /= BaseParams().DataDir();
+
+    if (fs::create_directories(path)) {
+        // This is the first run, create wallets subdirectory too
+        fs::create_directories(path / "wallets");
+    }
+
+    return path;
+}
+
+void ClearDatadirCache()
+{
+    LOCK(csPathCached);
+
+    pathCached = fs::path();
+    pathCachedNetSpecific = fs::path();
+    g_blocks_path_cached = fs::path();
+    g_blocks_path_cache_net_specific = fs::path();
+}
+
+fs::path GetConfigFile(const std::string& confPath)
+{
+    return AbsPathForConfigVal(fs::path(confPath), false);
+}
+
+static std::string TrimString(const std::string& str, const std::string& pattern)
+{
+    std::string::size_type front = str.find_first_not_of(pattern);
+    if (front == std::string::npos) {
+        return std::string();
+    }
+    std::string::size_type end = str.find_last_not_of(pattern);
+    return str.substr(front, end - front + 1);
+}
+
+static bool GetConfigOptions(std::istream& stream, std::string& error, std::vector<std::pair<std::string, std::string>> &options)
+{
+    std::string str, prefix;
+    std::string::size_type pos;
+    int linenr = 1;
+    while (std::getline(stream, str)) {
+        if ((pos = str.find('#')) != std::string::npos) {
+            str = str.substr(0, pos);
+        }
+        const static std::string pattern = " \t\r\n";
+        str = TrimString(str, pattern);
+        if (!str.empty()) {
+            if (*str.begin() == '[' && *str.rbegin() == ']') {
+                prefix = str.substr(1, str.size() - 2) + '.';
+            } else if (*str.begin() == '-') {
+                error = strprintf("parse error on line %i: %s, options in configuration file must be specified without leading -", linenr, str);
+                return false;
+            } else if ((pos = str.find('=')) != std::string::npos) {
+                std::string name = prefix + TrimString(str.substr(0, pos), pattern);
+                std::string value = TrimString(str.substr(pos + 1), pattern);
+                options.emplace_back(name, value);
+            } else {
+                error = strprintf("parse error on line %i: %s", linenr, str);
+                if (str.size() >= 2 && str.substr(0, 2) == "no") {
+                    error += strprintf(", if you intended to specify a negated option, use %s=1 instead", str);
+                }
+                return false;
+            }
+        }
+        ++linenr;
+    }
+    return true;
+}
+
+bool ArgsManager::ReadConfigStream(std::istream& stream, std::string& error, bool ignore_invalid_keys)
+{
+    LOCK(cs_args);
+    std::vector<std::pair<std::string, std::string>> options;
+    if (!GetConfigOptions(stream, error, options)) {
+        return false;
+    }
+    for (const std::pair<std::string, std::string>& option : options) {
+        std::string strKey = std::string("-") + option.first;
+        std::string strValue = option.second;
+
+        if (InterpretNegatedOption(strKey, strValue)) {
+            m_config_args[strKey].clear();
+        } else {
+            m_config_args[strKey].push_back(strValue);
+        }
+
+        // Check that the arg is known
+        if (!IsArgKnown(strKey)) {
+            if (!ignore_invalid_keys) {
+                error = strprintf("Invalid configuration value %s", option.first.c_str());
+                return false;
+            } else {
+                LogPrintf("Ignoring unknown configuration value %s\n", option.first);
+            }
+        }
+    }
+    return true;
+}
+
+bool ArgsManager::ReadConfigFiles(std::string& error, bool ignore_invalid_keys)
+{
+    {
+        LOCK(cs_args);
+        m_config_args.clear();
+    }
+
+    const std::string confPath = GetArg("-conf", BITCOIN_CONF_FILENAME);
+    fsbridge::ifstream stream(GetConfigFile(confPath));
+
+    // ok to not have a config file
+    if (stream.good()) {
+        if (!ReadConfigStream(stream, error, ignore_invalid_keys)) {
+            return false;
+        }
+        // if there is an -includeconf in the override args, but it is empty, that means the user
+        // passed '-noincludeconf' on the command line, in which case we should not include anything
+        bool emptyIncludeConf;
+        {
+            LOCK(cs_args);
+            emptyIncludeConf = m_override_args.count("-includeconf") == 0;
+        }
+        if (emptyIncludeConf) {
+            std::string chain_id = GetChainName();
+            std::vector<std::string> includeconf(GetArgs("-includeconf"));
+            {
+                // We haven't set m_network yet (that happens in SelectParams()), so manually check
+                // for network.includeconf args.
+                std::vector<std::string> includeconf_net(GetArgs(std::string("-") + chain_id + ".includeconf"));
+                includeconf.insert(includeconf.end(), includeconf_net.begin(), includeconf_net.end());
+            }
+
+            // Remove -includeconf from configuration, so we can warn about recursion
+            // later
+            {
+                LOCK(cs_args);
+                m_config_args.erase("-includeconf");
+                m_config_args.erase(std::string("-") + chain_id + ".includeconf");
+            }
+
+            for (const std::string& to_include : includeconf) {
+                fsbridge::ifstream include_config(GetConfigFile(to_include));
+                if (include_config.good()) {
+                    if (!ReadConfigStream(include_config, error, ignore_invalid_keys)) {
+                        return false;
+                    }
+                    LogPrintf("Included configuration file %s\n", to_include.c_str());
+                } else {
+                    error = "Failed to include configuration file " + to_include;
+                    return false;
+                }
+            }
+
+            // Warn about recursive -includeconf
+            includeconf = GetArgs("-includeconf");
+            {
+                std::vector<std::string> includeconf_net(GetArgs(std::string("-") + chain_id + ".includeconf"));
+                includeconf.insert(includeconf.end(), includeconf_net.begin(), includeconf_net.end());
+                std::string chain_id_final = GetChainName();
+                if (chain_id_final != chain_id) {
+                    // Also warn about recursive includeconf for the chain that was specified in one of the includeconfs
+                    includeconf_net = GetArgs(std::string("-") + chain_id_final + ".includeconf");
+                    includeconf.insert(includeconf.end(), includeconf_net.begin(), includeconf_net.end());
+                }
+            }
+            for (const std::string& to_include : includeconf) {
+                fprintf(stderr, "warning: -includeconf cannot be used from included files; ignoring -includeconf=%s\n", to_include.c_str());
+            }
+        }
+    }
+
+    // If datadir is changed in .conf file:
+    ClearDatadirCache();
+    if (!fs::is_directory(GetDataDir(false))) {
+        error = strprintf("specified data directory \"%s\" does not exist.", gArgs.GetArg("-datadir", "").c_str());
+        return false;
+    }
+    return true;
+}
+
+std::string ArgsManager::GetChainName() const
+{
+    LOCK(cs_args);
+    bool fRegTest = ArgsManagerHelper::GetNetBoolArg(*this, "-regtest");
+    bool fTestNet = ArgsManagerHelper::GetNetBoolArg(*this, "-testnet");
+
+    if (fTestNet && fRegTest)
+        throw std::runtime_error("Invalid combination of -regtest and -testnet.");
+    if (fRegTest)
+        return CBaseChainParams::REGTEST;
+    if (fTestNet)
+        return CBaseChainParams::TESTNET;
+    return CBaseChainParams::MAIN;
+}
+
+#ifndef WIN32
+fs::path GetPidFile()
+{
+    return AbsPathForConfigVal(fs::path(gArgs.GetArg("-pid", BITCOIN_PID_FILENAME)));
+}
+
+void CreatePidFile(const fs::path &path, pid_t pid)
+{
+    FILE* file = fsbridge::fopen(path, "w");
+    if (file)
+    {
+        fprintf(file, "%d\n", pid);
+        fclose(file);
+    }
+}
+#endif
+
+bool RenameOver(fs::path src, fs::path dest)
+{
+#ifdef WIN32
+    return MoveFileExW(src.wstring().c_str(), dest.wstring().c_str(),
+                       MOVEFILE_REPLACE_EXISTING) != 0;
+#else
+    int rc = std::rename(src.string().c_str(), dest.string().c_str());
+    return (rc == 0);
+#endif /* WIN32 */
+}
+
+/**
+ * Ignores exceptions thrown by Boost's create_directories if the requested directory exists.
+ * Specifically handles case where path p exists, but it wasn't possible for the user to
+ * write to the parent directory.
+ */
+bool TryCreateDirectories(const fs::path& p)
+{
+    try
+    {
+        return fs::create_directories(p);
+    } catch (const fs::filesystem_error&) {
+        if (!fs::exists(p) || !fs::is_directory(p))
+            throw;
+    }
+
+    // create_directories didn't create the directory, it had to have existed already
+    return false;
+}
+
+bool FileCommit(FILE *file)
+{
+    if (fflush(file) != 0) { // harmless if redundantly called
+        LogPrintf("%s: fflush failed: %d\n", __func__, errno);
+        return false;
+    }
+#ifdef WIN32
+    HANDLE hFile = (HANDLE)_get_osfhandle(_fileno(file));
+    if (FlushFileBuffers(hFile) == 0) {
+        LogPrintf("%s: FlushFileBuffers failed: %d\n", __func__, GetLastError());
+        return false;
+    }
+#else
+    #if defined(__linux__) || defined(__NetBSD__)
+    if (fdatasync(fileno(file)) != 0 && errno != EINVAL) { // Ignore EINVAL for filesystems that don't support sync
+        LogPrintf("%s: fdatasync failed: %d\n", __func__, errno);
+        return false;
+    }
+    #elif defined(MAC_OSX) && defined(F_FULLFSYNC)
+    if (fcntl(fileno(file), F_FULLFSYNC, 0) == -1) { // Manpage says "value other than -1" is returned on success
+        LogPrintf("%s: fcntl F_FULLFSYNC failed: %d\n", __func__, errno);
+        return false;
+    }
+    #else
+    if (fsync(fileno(file)) != 0 && errno != EINVAL) {
+        LogPrintf("%s: fsync failed: %d\n", __func__, errno);
+        return false;
+    }
+    #endif
+#endif
+    return true;
+}
+
+bool TruncateFile(FILE *file, unsigned int length) {
+#if defined(WIN32)
+    return _chsize(_fileno(file), length) == 0;
+#else
+    return ftruncate(fileno(file), length) == 0;
+#endif
+}
+
+/**
+ * this function tries to raise the file descriptor limit to the requested number.
+ * It returns the actual file descriptor limit (which may be more or less than nMinFD)
+ */
+int RaiseFileDescriptorLimit(int nMinFD) {
+#if defined(WIN32)
+    return 2048;
+#else
+    struct rlimit limitFD;
+    if (getrlimit(RLIMIT_NOFILE, &limitFD) != -1) {
+        if (limitFD.rlim_cur < (rlim_t)nMinFD) {
+            limitFD.rlim_cur = nMinFD;
+            if (limitFD.rlim_cur > limitFD.rlim_max)
+                limitFD.rlim_cur = limitFD.rlim_max;
+            setrlimit(RLIMIT_NOFILE, &limitFD);
+            getrlimit(RLIMIT_NOFILE, &limitFD);
+        }
+        return limitFD.rlim_cur;
+    }
+    return nMinFD; // getrlimit failed, assume it's fine
+#endif
+}
+
+/**
+ * this function tries to make a particular range of a file allocated (corresponding to disk space)
+ * it is advisory, and the range specified in the arguments will never contain live data
+ */
+void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length) {
+#if defined(WIN32)
+    // Windows-specific version
+    HANDLE hFile = (HANDLE)_get_osfhandle(_fileno(file));
+    LARGE_INTEGER nFileSize;
+    int64_t nEndPos = (int64_t)offset + length;
+    nFileSize.u.LowPart = nEndPos & 0xFFFFFFFF;
+    nFileSize.u.HighPart = nEndPos >> 32;
+    SetFilePointerEx(hFile, nFileSize, 0, FILE_BEGIN);
+    SetEndOfFile(hFile);
+#elif defined(MAC_OSX)
+    // OSX specific version
+    fstore_t fst;
+    fst.fst_flags = F_ALLOCATECONTIG;
+    fst.fst_posmode = F_PEOFPOSMODE;
+    fst.fst_offset = 0;
+    fst.fst_length = (off_t)offset + length;
+    fst.fst_bytesalloc = 0;
+    if (fcntl(fileno(file), F_PREALLOCATE, &fst) == -1) {
+        fst.fst_flags = F_ALLOCATEALL;
+        fcntl(fileno(file), F_PREALLOCATE, &fst);
+    }
+    ftruncate(fileno(file), fst.fst_length);
+#elif defined(__linux__)
+    // Version using posix_fallocate
+    off_t nEndPos = (off_t)offset + length;
+    posix_fallocate(fileno(file), 0, nEndPos);
+#else
+    // Fallback version
+    // TODO: just write one byte per block
+    static const char buf[65536] = {};
+    if (fseek(file, offset, SEEK_SET)) {
+        return;
+    }
+    while (length > 0) {
+        unsigned int now = 65536;
+        if (length < now)
+            now = length;
+        fwrite(buf, 1, now, file); // allowed to fail; this function is advisory anyway
+        length -= now;
+    }
+#endif
+}
+
+#ifdef WIN32
+fs::path GetSpecialFolderPath(int nFolder, bool fCreate)
+{
+    WCHAR pszPath[MAX_PATH] = L"";
+
+    if(SHGetSpecialFolderPathW(nullptr, pszPath, nFolder, fCreate))
+    {
+        return fs::path(pszPath);
+    }
+
+    LogPrintf("SHGetSpecialFolderPathW() failed, could not obtain requested path.\n");
+    return fs::path("");
+}
+#endif
+
+void runCommand(const std::string& strCommand)
+{
+    if (strCommand.empty()) return;
+#ifndef WIN32
+    int nErr = ::system(strCommand.c_str());
+#else
+    int nErr = ::_wsystem(std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>,wchar_t>().from_bytes(strCommand).c_str());
+#endif
+    if (nErr)
+        LogPrintf("runCommand error: system(%s) returned %d\n", strCommand, nErr);
+}
+
+void RenameThread(const char* name)
+{
+#if defined(PR_SET_NAME)
+    // Only the first 15 characters are used (16 - NUL terminator)
+    ::prctl(PR_SET_NAME, name, 0, 0, 0);
+#elif (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
+    pthread_set_name_np(pthread_self(), name);
+
+#elif defined(MAC_OSX)
+    pthread_setname_np(name);
+#else
+    // Prevent warnings for unused parameters...
+    (void)name;
+#endif
+}
+
+void SetupEnvironment()
+{
+#ifdef HAVE_MALLOPT_ARENA_MAX
+    // glibc-specific: On 32-bit systems set the number of arenas to 1.
+    // By default, since glibc 2.10, the C library will create up to two heap
+    // arenas per core. This is known to cause excessive virtual address space
+    // usage in our usage. Work around it by setting the maximum number of
+    // arenas to 1.
+    if (sizeof(void*) == 4) {
+        mallopt(M_ARENA_MAX, 1);
+    }
+#endif
+    // On most POSIX systems (e.g. Linux, but not BSD) the environment's locale
+    // may be invalid, in which case the "C" locale is used as fallback.
+#if !defined(WIN32) && !defined(MAC_OSX) && !defined(__FreeBSD__) && !defined(__OpenBSD__)
+    try {
+        std::locale(""); // Raises a runtime error if current locale is invalid
+    } catch (const std::runtime_error&) {
+        setenv("LC_ALL", "C", 1);
+    }
+#elif defined(WIN32)
+    // Set the default input/output charset is utf-8
+    SetConsoleCP(CP_UTF8);
+    SetConsoleOutputCP(CP_UTF8);
+#endif
+    // The path locale is lazy initialized and to avoid deinitialization errors
+    // in multithreading environments, it is set explicitly by the main thread.
+    // A dummy locale is used to extract the internal default locale, used by
+    // fs::path, which is then used to explicitly imbue the path.
+    std::locale loc = fs::path::imbue(std::locale::classic());
+#ifndef WIN32
+    fs::path::imbue(loc);
+#else
+    fs::path::imbue(std::locale(loc, new std::codecvt_utf8_utf16<wchar_t>()));
+#endif
+}
+
+bool SetupNetworking()
+{
+#ifdef WIN32
+    // Initialize Windows Sockets
+    WSADATA wsadata;
+    int ret = WSAStartup(MAKEWORD(2,2), &wsadata);
+    if (ret != NO_ERROR || LOBYTE(wsadata.wVersion ) != 2 || HIBYTE(wsadata.wVersion) != 2)
+        return false;
+#endif
+    return true;
+}
+
+int GetNumCores()
+{
+    return std::thread::hardware_concurrency();
+}
+
+std::string CopyrightHolders(const std::string& strPrefix)
+{
+    std::string strCopyrightHolders = strPrefix + strprintf(_(COPYRIGHT_HOLDERS), _(COPYRIGHT_HOLDERS_SUBSTITUTION));
+
+    // Check for untranslated substitution to make sure Bitcoin Core copyright is not removed by accident
+    if (strprintf(COPYRIGHT_HOLDERS, COPYRIGHT_HOLDERS_SUBSTITUTION).find("Bitcoin Core") == std::string::npos) {
+        strCopyrightHolders += "\n" + strPrefix + "The Bitcoin Core developers";
+    }
+    return strCopyrightHolders;
+}
+
+// Obtain the application startup time (used for uptime calculation)
+int64_t GetStartupTime()
+{
+    return nStartupTime;
+}
+
+fs::path AbsPathForConfigVal(const fs::path& path, bool net_specific)
+{
+    return fs::absolute(path, GetDataDir(net_specific));
+}
+
+int ScheduleBatchPriority()
+{
+#ifdef SCHED_BATCH
+    const static sched_param param{0};
+    if (int ret = pthread_setschedparam(pthread_self(), SCHED_BATCH, &param)) {
+        LogPrintf("Failed to pthread_setschedparam: %s\n", strerror(errno));
+        return ret;
+    }
+    return 0;
+#else
+    return 1;
+#endif
+}
+
+namespace util {
+#ifdef WIN32
+WinCmdLineArgs::WinCmdLineArgs()
+{
+    wchar_t** wargv = CommandLineToArgvW(GetCommandLineW(), &argc);
+    std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>, wchar_t> utf8_cvt;
+    argv = new char*[argc];
+    args.resize(argc);
+    for (int i = 0; i < argc; i++) {
+        args[i] = utf8_cvt.to_bytes(wargv[i]);
+        argv[i] = &*args[i].begin();
+    }
+    LocalFree(wargv);
+}
+
+WinCmdLineArgs::~WinCmdLineArgs()
+{
+    delete[] argv;
+}
+
+std::pair<int, char**> WinCmdLineArgs::get()
+{
+    return std::make_pair(argc, argv);
+}
+#endif
+} // namespace util
diff --git a/src/util/system.h b/src/util/system.h
new file mode 100644
index 0000000000..5634b8dd61
--- /dev/null
+++ b/src/util/system.h
@@ -0,0 +1,382 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+/**
+ * Server/client environment: argument handling, config file parsing,
+ * thread wrappers, startup time
+ */
+#ifndef BITCOIN_UTIL_SYSTEM_H
+#define BITCOIN_UTIL_SYSTEM_H
+
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h>
+#endif
+
+#include <compat.h>
+#include <fs.h>
+#include <logging.h>
+#include <sync.h>
+#include <tinyformat.h>
+#include <util/memory.h>
+#include <util/time.h>
+
+#include <atomic>
+#include <exception>
+#include <map>
+#include <set>
+#include <stdint.h>
+#include <string>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+
+#include <boost/thread/condition_variable.hpp> // for boost::thread_interrupted
+
+// Application startup time (used for uptime calculation)
+int64_t GetStartupTime();
+
+extern const char * const BITCOIN_CONF_FILENAME;
+extern const char * const BITCOIN_PID_FILENAME;
+
+/** Translate a message to the native language of the user. */
+const extern std::function<std::string(const char*)> G_TRANSLATION_FUN;
+
+/**
+ * Translation function.
+ * If no translation function is set, simply return the input.
+ */
+inline std::string _(const char* psz)
+{
+    return G_TRANSLATION_FUN ? (G_TRANSLATION_FUN)(psz) : psz;
+}
+
+void SetupEnvironment();
+bool SetupNetworking();
+
+template<typename... Args>
+bool error(const char* fmt, const Args&... args)
+{
+    LogPrintf("ERROR: %s\n", tfm::format(fmt, args...));
+    return false;
+}
+
+void PrintExceptionContinue(const std::exception *pex, const char* pszThread);
+bool FileCommit(FILE *file);
+bool TruncateFile(FILE *file, unsigned int length);
+int RaiseFileDescriptorLimit(int nMinFD);
+void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length);
+bool RenameOver(fs::path src, fs::path dest);
+bool LockDirectory(const fs::path& directory, const std::string lockfile_name, bool probe_only=false);
+bool DirIsWritable(const fs::path& directory);
+
+/** Release all directory locks. This is used for unit testing only, at runtime
+ * the global destructor will take care of the locks.
+ */
+void ReleaseDirectoryLocks();
+
+bool TryCreateDirectories(const fs::path& p);
+fs::path GetDefaultDataDir();
+const fs::path &GetBlocksDir(bool fNetSpecific = true);
+const fs::path &GetDataDir(bool fNetSpecific = true);
+void ClearDatadirCache();
+fs::path GetConfigFile(const std::string& confPath);
+#ifndef WIN32
+fs::path GetPidFile();
+void CreatePidFile(const fs::path &path, pid_t pid);
+#endif
+#ifdef WIN32
+fs::path GetSpecialFolderPath(int nFolder, bool fCreate = true);
+#endif
+void runCommand(const std::string& strCommand);
+
+/**
+ * Most paths passed as configuration arguments are treated as relative to
+ * the datadir if they are not absolute.
+ *
+ * @param path The path to be conditionally prefixed with datadir.
+ * @param net_specific Forwarded to GetDataDir().
+ * @return The normalized path.
+ */
+fs::path AbsPathForConfigVal(const fs::path& path, bool net_specific = true);
+
+inline bool IsSwitchChar(char c)
+{
+#ifdef WIN32
+    return c == '-' || c == '/';
+#else
+    return c == '-';
+#endif
+}
+
+enum class OptionsCategory {
+    OPTIONS,
+    CONNECTION,
+    WALLET,
+    WALLET_DEBUG_TEST,
+    ZMQ,
+    DEBUG_TEST,
+    CHAINPARAMS,
+    NODE_RELAY,
+    BLOCK_CREATION,
+    RPC,
+    GUI,
+    COMMANDS,
+    REGISTER_COMMANDS,
+
+    HIDDEN // Always the last option to avoid printing these in the help
+};
+
+class ArgsManager
+{
+protected:
+    friend class ArgsManagerHelper;
+
+    struct Arg
+    {
+        std::string m_help_param;
+        std::string m_help_text;
+        bool m_debug_only;
+
+        Arg(const std::string& help_param, const std::string& help_text, bool debug_only) : m_help_param(help_param), m_help_text(help_text), m_debug_only(debug_only) {};
+    };
+
+    mutable CCriticalSection cs_args;
+    std::map<std::string, std::vector<std::string>> m_override_args GUARDED_BY(cs_args);
+    std::map<std::string, std::vector<std::string>> m_config_args GUARDED_BY(cs_args);
+    std::string m_network GUARDED_BY(cs_args);
+    std::set<std::string> m_network_only_args GUARDED_BY(cs_args);
+    std::map<OptionsCategory, std::map<std::string, Arg>> m_available_args GUARDED_BY(cs_args);
+
+    bool ReadConfigStream(std::istream& stream, std::string& error, bool ignore_invalid_keys = false);
+
+public:
+    ArgsManager();
+
+    /**
+     * Select the network in use
+     */
+    void SelectConfigNetwork(const std::string& network);
+
+    bool ParseParameters(int argc, const char* const argv[], std::string& error);
+    bool ReadConfigFiles(std::string& error, bool ignore_invalid_keys = false);
+
+    /**
+     * Log warnings for options in m_section_only_args when
+     * they are specified in the default section but not overridden
+     * on the command line or in a network-specific section in the
+     * config file.
+     */
+    void WarnForSectionOnlyArgs();
+
+    /**
+     * Return a vector of strings of the given argument
+     *
+     * @param strArg Argument to get (e.g. "-foo")
+     * @return command-line arguments
+     */
+    std::vector<std::string> GetArgs(const std::string& strArg) const;
+
+    /**
+     * Return true if the given argument has been manually set
+     *
+     * @param strArg Argument to get (e.g. "-foo")
+     * @return true if the argument has been set
+     */
+    bool IsArgSet(const std::string& strArg) const;
+
+    /**
+     * Return true if the argument was originally passed as a negated option,
+     * i.e. -nofoo.
+     *
+     * @param strArg Argument to get (e.g. "-foo")
+     * @return true if the argument was passed negated
+     */
+    bool IsArgNegated(const std::string& strArg) const;
+
+    /**
+     * Return string argument or default value
+     *
+     * @param strArg Argument to get (e.g. "-foo")
+     * @param strDefault (e.g. "1")
+     * @return command-line argument or default value
+     */
+    std::string GetArg(const std::string& strArg, const std::string& strDefault) const;
+
+    /**
+     * Return integer argument or default value
+     *
+     * @param strArg Argument to get (e.g. "-foo")
+     * @param nDefault (e.g. 1)
+     * @return command-line argument (0 if invalid number) or default value
+     */
+    int64_t GetArg(const std::string& strArg, int64_t nDefault) const;
+
+    /**
+     * Return boolean argument or default value
+     *
+     * @param strArg Argument to get (e.g. "-foo")
+     * @param fDefault (true or false)
+     * @return command-line argument or default value
+     */
+    bool GetBoolArg(const std::string& strArg, bool fDefault) const;
+
+    /**
+     * Set an argument if it doesn't already have a value
+     *
+     * @param strArg Argument to set (e.g. "-foo")
+     * @param strValue Value (e.g. "1")
+     * @return true if argument gets set, false if it already had a value
+     */
+    bool SoftSetArg(const std::string& strArg, const std::string& strValue);
+
+    /**
+     * Set a boolean argument if it doesn't already have a value
+     *
+     * @param strArg Argument to set (e.g. "-foo")
+     * @param fValue Value (e.g. false)
+     * @return true if argument gets set, false if it already had a value
+     */
+    bool SoftSetBoolArg(const std::string& strArg, bool fValue);
+
+    // Forces an arg setting. Called by SoftSetArg() if the arg hasn't already
+    // been set. Also called directly in testing.
+    void ForceSetArg(const std::string& strArg, const std::string& strValue);
+
+    /**
+     * Looks for -regtest, -testnet and returns the appropriate BIP70 chain name.
+     * @return CBaseChainParams::MAIN by default; raises runtime error if an invalid combination is given.
+     */
+    std::string GetChainName() const;
+
+    /**
+     * Add argument
+     */
+    void AddArg(const std::string& name, const std::string& help, const bool debug_only, const OptionsCategory& cat);
+
+    /**
+     * Add many hidden arguments
+     */
+    void AddHiddenArgs(const std::vector<std::string>& args);
+
+    /**
+     * Clear available arguments
+     */
+    void ClearArgs() {
+        LOCK(cs_args);
+        m_available_args.clear();
+    }
+
+    /**
+     * Get the help string
+     */
+    std::string GetHelpMessage() const;
+
+    /**
+     * Check whether we know of this arg
+     */
+    bool IsArgKnown(const std::string& key) const;
+};
+
+extern ArgsManager gArgs;
+
+/**
+ * @return true if help has been requested via a command-line arg
+ */
+bool HelpRequested(const ArgsManager& args);
+
+/**
+ * Format a string to be used as group of options in help messages
+ *
+ * @param message Group name (e.g. "RPC server options:")
+ * @return the formatted string
+ */
+std::string HelpMessageGroup(const std::string& message);
+
+/**
+ * Format a string to be used as option description in help messages
+ *
+ * @param option Option message (e.g. "-rpcuser=<user>")
+ * @param message Option description (e.g. "Username for JSON-RPC connections")
+ * @return the formatted string
+ */
+std::string HelpMessageOpt(const std::string& option, const std::string& message);
+
+/**
+ * Return the number of cores available on the current system.
+ * @note This does count virtual cores, such as those provided by HyperThreading.
+ */
+int GetNumCores();
+
+void RenameThread(const char* name);
+
+/**
+ * .. and a wrapper that just calls func once
+ */
+template <typename Callable> void TraceThread(const char* name,  Callable func)
+{
+    std::string s = strprintf("bitcoin-%s", name);
+    RenameThread(s.c_str());
+    try
+    {
+        LogPrintf("%s thread start\n", name);
+        func();
+        LogPrintf("%s thread exit\n", name);
+    }
+    catch (const boost::thread_interrupted&)
+    {
+        LogPrintf("%s thread interrupt\n", name);
+        throw;
+    }
+    catch (const std::exception& e) {
+        PrintExceptionContinue(&e, name);
+        throw;
+    }
+    catch (...) {
+        PrintExceptionContinue(nullptr, name);
+        throw;
+    }
+}
+
+std::string CopyrightHolders(const std::string& strPrefix);
+
+/**
+ * On platforms that support it, tell the kernel the calling thread is
+ * CPU-intensive and non-interactive. See SCHED_BATCH in sched(7) for details.
+ *
+ * @return The return value of sched_setschedule(), or 1 on systems without
+ * sched_setschedule().
+ */
+int ScheduleBatchPriority();
+
+namespace util {
+
+//! Simplification of std insertion
+template <typename Tdst, typename Tsrc>
+inline void insert(Tdst& dst, const Tsrc& src) {
+    dst.insert(dst.begin(), src.begin(), src.end());
+}
+template <typename TsetT, typename Tsrc>
+inline void insert(std::set<TsetT>& dst, const Tsrc& src) {
+    dst.insert(src.begin(), src.end());
+}
+
+#ifdef WIN32
+class WinCmdLineArgs
+{
+public:
+    WinCmdLineArgs();
+    ~WinCmdLineArgs();
+    std::pair<int, char**> get();
+
+private:
+    int argc;
+    char** argv;
+    std::vector<std::string> args;
+};
+#endif
+
+} // namespace util
+
+#endif // BITCOIN_UTIL_SYSTEM_H
diff --git a/src/util/time.cpp b/src/util/time.cpp
new file mode 100644
index 0000000000..83a7937d8f
--- /dev/null
+++ b/src/util/time.cpp
@@ -0,0 +1,110 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h>
+#endif
+
+#include <util/time.h>
+
+#include <atomic>
+#include <boost/date_time/posix_time/posix_time.hpp>
+#include <boost/thread.hpp>
+#include <ctime>
+#include <tinyformat.h>
+
+static std::atomic<int64_t> nMockTime(0); //!< For unit testing
+
+int64_t GetTime()
+{
+    int64_t mocktime = nMockTime.load(std::memory_order_relaxed);
+    if (mocktime) return mocktime;
+
+    time_t now = time(nullptr);
+    assert(now > 0);
+    return now;
+}
+
+void SetMockTime(int64_t nMockTimeIn)
+{
+    nMockTime.store(nMockTimeIn, std::memory_order_relaxed);
+}
+
+int64_t GetMockTime()
+{
+    return nMockTime.load(std::memory_order_relaxed);
+}
+
+int64_t GetTimeMillis()
+{
+    int64_t now = (boost::posix_time::microsec_clock::universal_time() -
+                   boost::posix_time::ptime(boost::gregorian::date(1970,1,1))).total_milliseconds();
+    assert(now > 0);
+    return now;
+}
+
+int64_t GetTimeMicros()
+{
+    int64_t now = (boost::posix_time::microsec_clock::universal_time() -
+                   boost::posix_time::ptime(boost::gregorian::date(1970,1,1))).total_microseconds();
+    assert(now > 0);
+    return now;
+}
+
+int64_t GetSystemTimeInSeconds()
+{
+    return GetTimeMicros()/1000000;
+}
+
+void MilliSleep(int64_t n)
+{
+
+/**
+ * Boost's sleep_for was uninterruptible when backed by nanosleep from 1.50
+ * until fixed in 1.52. Use the deprecated sleep method for the broken case.
+ * See: https://svn.boost.org/trac/boost/ticket/7238
+ */
+#if defined(HAVE_WORKING_BOOST_SLEEP_FOR)
+    boost::this_thread::sleep_for(boost::chrono::milliseconds(n));
+#elif defined(HAVE_WORKING_BOOST_SLEEP)
+    boost::this_thread::sleep(boost::posix_time::milliseconds(n));
+#else
+//should never get here
+#error missing boost sleep implementation
+#endif
+}
+
+std::string FormatISO8601DateTime(int64_t nTime) {
+    struct tm ts;
+    time_t time_val = nTime;
+#ifdef _MSC_VER
+    gmtime_s(&ts, &time_val);
+#else
+    gmtime_r(&time_val, &ts);
+#endif
+    return strprintf("%04i-%02i-%02iT%02i:%02i:%02iZ", ts.tm_year + 1900, ts.tm_mon + 1, ts.tm_mday, ts.tm_hour, ts.tm_min, ts.tm_sec);
+}
+
+std::string FormatISO8601Date(int64_t nTime) {
+    struct tm ts;
+    time_t time_val = nTime;
+#ifdef _MSC_VER
+    gmtime_s(&ts, &time_val);
+#else
+    gmtime_r(&time_val, &ts);
+#endif
+    return strprintf("%04i-%02i-%02i", ts.tm_year + 1900, ts.tm_mon + 1, ts.tm_mday);
+}
+
+std::string FormatISO8601Time(int64_t nTime) {
+    struct tm ts;
+    time_t time_val = nTime;
+#ifdef _MSC_VER
+    gmtime_s(&ts, &time_val);
+#else
+    gmtime_r(&time_val, &ts);
+#endif
+    return strprintf("%02i:%02i:%02iZ", ts.tm_hour, ts.tm_min, ts.tm_sec);
+}
diff --git a/src/util/time.h b/src/util/time.h
new file mode 100644
index 0000000000..f2e2747434
--- /dev/null
+++ b/src/util/time.h
@@ -0,0 +1,38 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_TIME_H
+#define BITCOIN_UTIL_TIME_H
+
+#include <stdint.h>
+#include <string>
+
+/**
+ * GetTimeMicros() and GetTimeMillis() both return the system time, but in
+ * different units. GetTime() returns the system time in seconds, but also
+ * supports mocktime, where the time can be specified by the user, eg for
+ * testing (eg with the setmocktime rpc, or -mocktime argument).
+ *
+ * TODO: Rework these functions to be type-safe (so that we don't inadvertently
+ * compare numbers with different units, or compare a mocktime to system time).
+ */
+
+int64_t GetTime();
+int64_t GetTimeMillis();
+int64_t GetTimeMicros();
+int64_t GetSystemTimeInSeconds(); // Like GetTime(), but not mockable
+void SetMockTime(int64_t nMockTimeIn);
+int64_t GetMockTime();
+void MilliSleep(int64_t n);
+
+/**
+ * ISO 8601 formatting is preferred. Use the FormatISO8601{DateTime,Date,Time}
+ * helper functions if possible.
+ */
+std::string FormatISO8601DateTime(int64_t nTime);
+std::string FormatISO8601Date(int64_t nTime);
+std::string FormatISO8601Time(int64_t nTime);
+
+#endif // BITCOIN_UTIL_TIME_H