diff options
Diffstat (limited to 'lib/snprintf.c')
-rw-r--r-- | lib/snprintf.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/lib/snprintf.c b/lib/snprintf.c new file mode 100644 index 0000000..8a9971b --- /dev/null +++ b/lib/snprintf.c @@ -0,0 +1,71 @@ +/* Formatted output to strings. + Copyright (C) 2004, 2006-2018 Free Software Foundation, Inc. + Written by Simon Josefsson and Paul Eggert. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License along + with this program; if not, see <https://www.gnu.org/licenses/>. */ + +#include <config.h> + +/* Specification. */ +#include <stdio.h> + +#include <errno.h> +#include <limits.h> +#include <stdarg.h> +#include <stdlib.h> +#include <string.h> + +#include "vasnprintf.h" + +/* Print formatted output to string STR. Similar to sprintf, but + additional length SIZE limit how much is written into STR. Returns + string length of formatted string (which may be larger than SIZE). + STR may be NULL, in which case nothing will be written. On error, + return a negative value. */ +int +snprintf (char *str, size_t size, const char *format, ...) +{ + char *output; + size_t len; + size_t lenbuf = size; + va_list args; + + va_start (args, format); + output = vasnprintf (str, &lenbuf, format, args); + len = lenbuf; + va_end (args); + + if (!output) + return -1; + + if (output != str) + { + if (size) + { + size_t pruned_len = (len < size ? len : size - 1); + memcpy (str, output, pruned_len); + str[pruned_len] = '\0'; + } + + free (output); + } + + if (INT_MAX < len) + { + errno = EOVERFLOW; + return -1; + } + + return len; +} |