Implement basic character sets for the '%[]' conversion specifier. The '%[]' conversion specifier matches a nonempty sequence of characters from the specified set of accepted (or with '^', rejected) characters between the brackets. The substring matched is to be made up of characters in (or not in) the set. This implementation differs from its glibc counterpart in that it does not support character ranges (e.g., 'a-z' or '0-9'), the hyphen '-' is *not* a special character, and the brackets themselves cannot be matched.
Signed-off-by: Jessica Yu <[email protected]> --- lib/vsprintf.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 525c8e1..6ee3e7f 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -2714,6 +2714,41 @@ int vsscanf(const char *buf, const char *fmt, va_list args) num++; } continue; + case '[': + { + char *s = (char *)va_arg(args, char *); + char set[U8_MAX] = { 0 }; + size_t (*op)(const char *str, const char *set); + size_t len = 0; + bool negate = (*(fmt) == '^'); + + if (field_width == -1) + field_width = SHRT_MAX; + + op = negate ? &strcspn : &strspn; + if (negate) + fmt++; + + len = strcspn(fmt, "]"); + /* invalid format; stop here */ + if (!len) + return num; + + strncpy(set, fmt, len); + /* advance fmt past ']' */ + fmt += len + 1; + + len = (*op)(str, set); + /* no matches */ + if (!len) + return num; + + while (*str && len-- && field_width--) + *s++ = *str++; + *s = '\0'; + num++; + } + continue; case 'o': base = 8; break; -- 2.4.3
