diff options
Diffstat (limited to 'strbuf.c')
| -rw-r--r-- | strbuf.c | 29 |
1 files changed, 29 insertions, 0 deletions
@@ -709,3 +709,32 @@ char *xstrfmt(const char *fmt, ...) return ret; } + +void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm) +{ + size_t len; + + /* + * strftime reports "0" if it could not fit the result in the buffer. + * Unfortunately, it also reports "0" if the requested time string + * takes 0 bytes. So if we were to probe and grow, we have to choose + * some arbitrary cap beyond which we guess that the format probably + * just results in a 0-length output. Since we have to choose some + * reasonable cap anyway, and since it is not that big, we may + * as well just grow to their in the first place. + */ + strbuf_grow(sb, 128); + len = strftime(sb->buf + sb->len, sb->alloc - sb->len, fmt, tm); + + if (!len) { + /* + * Either we failed, or the format actually produces a 0-length + * output. There's not much we can do, so we leave it blank. + * However, the output array is left in an undefined state, so + * we must re-assert our NUL terminator. + */ + sb->buf[sb->len] = '\0'; + } else { + sb->len += len; + } +} |