diff options
Diffstat (limited to 'util/cutils.c')
-rw-r--r-- | util/cutils.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/util/cutils.c b/util/cutils.c index 80bb1dcbf7..1439da4f99 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -270,6 +270,105 @@ int64_t strtosz(const char *nptr, char **end) return strtosz_suffix(nptr, end, STRTOSZ_DEFSUFFIX_MB); } +/** + * parse_uint: + * + * @s: String to parse + * @value: Destination for parsed integer value + * @endptr: Destination for pointer to first character not consumed + * @base: integer base, between 2 and 36 inclusive, or 0 + * + * Parse unsigned integer + * + * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional + * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits. + * + * If @s is null, or @base is invalid, or @s doesn't start with an + * integer in the syntax above, set *@value to 0, *@endptr to @s, and + * return -EINVAL. + * + * Set *@endptr to point right beyond the parsed integer (even if the integer + * overflows or is negative, all digits will be parsed and *@endptr will + * point right beyond them). + * + * If the integer is negative, set *@value to 0, and return -ERANGE. + * + * If the integer overflows unsigned long long, set *@value to + * ULLONG_MAX, and return -ERANGE. + * + * Else, set *@value to the parsed integer, and return 0. + */ +int parse_uint(const char *s, unsigned long long *value, char **endptr, + int base) +{ + int r = 0; + char *endp = (char *)s; + unsigned long long val = 0; + + if (!s) { + r = -EINVAL; + goto out; + } + + errno = 0; + val = strtoull(s, &endp, base); + if (errno) { + r = -errno; + goto out; + } + + if (endp == s) { + r = -EINVAL; + goto out; + } + + /* make sure we reject negative numbers: */ + while (isspace((unsigned char)*s)) { + s++; + } + if (*s == '-') { + val = 0; + r = -ERANGE; + goto out; + } + +out: + *value = val; + *endptr = endp; + return r; +} + +/** + * parse_uint_full: + * + * @s: String to parse + * @value: Destination for parsed integer value + * @base: integer base, between 2 and 36 inclusive, or 0 + * + * Parse unsigned integer from entire string + * + * Have the same behavior of parse_uint(), but with an additional check + * for additional data after the parsed number. If extra characters are present + * after the parsed number, the function will return -EINVAL, and *@v will + * be set to 0. + */ +int parse_uint_full(const char *s, unsigned long long *value, int base) +{ + char *endp; + int r; + + r = parse_uint(s, value, &endp, base); + if (r < 0) { + return r; + } + if (*endp) { + *value = 0; + return -EINVAL; + } + + return 0; +} + int qemu_parse_fd(const char *param) { int fd; |