Add "bitcoin-tx" command line utility and supporting modules.

This is a simple utility that provides command line manipulation of
a hex-encoded TX. The utility takes a hex string on the command line
as input, performs zero or more mutations, and outputs a hex string
to standard output.

This utility is also an intentional exercise of the "bitcoin library"
concept. It is designed to require minimal libraries, and works
entirely without need for any RPC or P2P communication.

See "bitcoin-tx --help" for command and options summary.

1 files changed, 145 insertions, 0 deletions

diff --git a/src/univalue/univalue_write.cpp b/src/univalue/univalue_write.cpp
new file mode 100644
index 0000000000..1818f5c6f9
--- /dev/null
+++ b/src/univalue/univalue_write.cpp
@@ -0,0 +1,145 @@
+// Copyright 2014 BitPay Inc.
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <ctype.h>
+#include <stdio.h>
+#include "univalue.h"
+
+// TODO: Using UTF8
+
+using namespace std;
+
+static bool initEscapes;
+static const char *escapes[256];
+
+static void initJsonEscape()
+{
+    escapes['"'] = "\\\"";
+    escapes['\\'] = "\\\\";
+    escapes['/'] = "\\/";
+    escapes['\b'] = "\\b";
+    escapes['\f'] = "\\f";
+    escapes['\n'] = "\\n";
+    escapes['\r'] = "\\r";
+    escapes['\t'] = "\\t";
+
+    initEscapes = true;
+}
+
+static string json_escape(const string& inS)
+{
+    if (!initEscapes)
+        initJsonEscape();
+
+    string outS;
+    outS.reserve(inS.size() * 2);
+
+    for (unsigned int i = 0; i < inS.size(); i++) {
+        unsigned char ch = inS[i];
+        const char *escStr = escapes[ch];
+
+        if (escStr)
+            outS += escStr;
+
+        else if (isprint(ch))
+            outS += ch;
+
+        else {
+            char tmpesc[16];
+            sprintf(tmpesc, "\\u%04x", ch);
+            outS += tmpesc;
+        }
+    }
+
+    return outS;
+}
+
+string UniValue::write(unsigned int prettyIndent,
+                       unsigned int indentLevel) const
+{
+    string s;
+    s.reserve(1024);
+
+    unsigned int modIndent = indentLevel;
+    if (modIndent == 0)
+        modIndent = 1;
+
+    switch (typ) {
+    case VNULL:
+        s += "null";
+        break;
+    case VOBJ:
+        writeObject(prettyIndent, modIndent, s);
+        break;
+    case VARR:
+        writeArray(prettyIndent, modIndent, s);
+        break;
+    case VSTR:
+        s += "\"" + json_escape(val) + "\"";
+        break;
+    case VNUM:
+        s += val;
+        break;
+    case VBOOL:
+        s += (val == "1" ? "true" : "false");
+        break;
+    }
+
+    return s;
+}
+
+static string spaceStr;
+
+static string indentStr(unsigned int prettyIndent, unsigned int indentLevel)
+{
+    unsigned int spaces = prettyIndent * indentLevel;
+    while (spaceStr.size() < spaces)
+        spaceStr += "                ";
+
+    return spaceStr.substr(0, spaces);
+}
+
+void UniValue::writeArray(unsigned int prettyIndent, unsigned int indentLevel, string& s) const
+{
+    s += "[";
+    if (prettyIndent)
+        s += "\n";
+
+    for (unsigned int i = 0; i < values.size(); i++) {
+        if (prettyIndent)
+            s += indentStr(prettyIndent, indentLevel);
+        s += values[i].write(prettyIndent, indentLevel + 1);
+        if (i != (values.size() - 1))
+            s += ", ";
+        if (prettyIndent)
+            s += "\n";
+    }
+
+    if (prettyIndent)
+        s += indentStr(prettyIndent, indentLevel - 1);
+    s += "]";
+}
+
+void UniValue::writeObject(unsigned int prettyIndent, unsigned int indentLevel, string& s) const
+{
+    s += "{";
+    if (prettyIndent)
+        s += "\n";
+
+    for (unsigned int i = 0; i < keys.size(); i++) {
+        if (prettyIndent)
+            s += indentStr(prettyIndent, indentLevel);
+        s += "\"" + json_escape(keys[i]) + "\": ";
+        s += values[i].write(prettyIndent, indentLevel + 1);
+        if (i != (values.size() - 1))
+            s += ",";
+        if (prettyIndent)
+            s += "\n";
+    }
+
+    if (prettyIndent)
+        s += indentStr(prettyIndent, indentLevel - 1);
+    s += "}";
+}
+