coreutils/lib/addext.c
Jim Meyering 7fda17ac4f (<errno.h>): Include.
(errno): Declare if not defined.
(addext): Work correctly when pathconf returns -1 and leaves
errno alone because there is no limit.  Also, work even if
pathconf returns a value greater than SIZE_MAX.
2001-08-13 06:30:10 +00:00

115 lines
2.7 KiB
C

/* addext.c -- add an extension to a file name
Copyright 1990, 1997, 1998, 1999, 2001 Free Software Foundation, Inc.
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 2, 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; see the file COPYING.
If not, write to the Free Software Foundation,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Written by David MacKenzie <djm@gnu.ai.mit.edu> and Paul Eggert */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#ifndef HAVE_DOS_FILE_NAMES
# define HAVE_DOS_FILE_NAMES 0
#endif
#ifndef HAVE_LONG_FILE_NAMES
# define HAVE_LONG_FILE_NAMES 0
#endif
#if HAVE_LIMITS_H
# include <limits.h>
#endif
#ifndef _POSIX_NAME_MAX
# define _POSIX_NAME_MAX 14
#endif
#include <sys/types.h>
#if HAVE_STRING_H
# include <string.h>
#else
# include <strings.h>
#endif
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <errno.h>
#ifndef errno
extern int errno;
#endif
#include "backupfile.h"
#include "dirname.h"
/* Append to FILENAME the extension EXT, unless the result would be too long,
in which case just append the character E. */
void
addext (char *filename, char const *ext, int e)
{
char *s = base_name (filename);
size_t slen = base_len (s);
size_t extlen = strlen (ext);
size_t slen_max = HAVE_LONG_FILE_NAMES ? 255 : _POSIX_NAME_MAX;
#if HAVE_PATHCONF && defined _PC_NAME_MAX
if (_POSIX_NAME_MAX < slen + extlen || HAVE_DOS_FILE_NAMES)
{
/* The new base name is long enough to require a pathconf check. */
long name_max;
errno = 0;
if (s == filename)
name_max = pathconf (".", _PC_NAME_MAX);
else
{
char c = *s;
if (! ISSLASH (c))
*s = 0;
name_max = pathconf (filename, _PC_NAME_MAX);
*s = c;
}
if (0 <= name_max || errno == 0)
slen_max = name_max == (size_t) name_max ? name_max : -1;
}
#endif
if (HAVE_DOS_FILE_NAMES && slen_max <= 12)
{
/* Live within DOS's 8.3 limit. */
char *dot = strchr (s, '.');
if (dot)
{
slen -= dot + 1 - s;
s = dot + 1;
slen_max = 3;
}
else
slen_max = 8;
extlen = 9; /* Don't use EXT. */
}
if (slen + extlen <= slen_max)
strcpy (s + slen, ext);
else
{
if (slen_max <= slen)
slen = slen_max - 1;
s[slen] = e;
s[slen + 1] = 0;
}
}