253 lines
6.6 KiB
C
253 lines
6.6 KiB
C
/* backupfile.c -- make Emacs style backup file names
|
|
Copyright (C) 1990,1991,1992,1993,1995,1997 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>.
|
|
Some algorithms adapted from GNU Emacs. */
|
|
|
|
#if HAVE_CONFIG_H
|
|
# include <config.h>
|
|
#endif
|
|
|
|
#include <argmatch.h>
|
|
#include <backupfile.h>
|
|
|
|
#include <stdio.h>
|
|
#include <sys/types.h>
|
|
#if HAVE_STRING_H
|
|
# include <string.h>
|
|
#else
|
|
# include <strings.h>
|
|
#endif
|
|
|
|
#if HAVE_DIRENT_H
|
|
# include <dirent.h>
|
|
# define NLENGTH(direct) strlen ((direct)->d_name)
|
|
#else
|
|
# define dirent direct
|
|
# define NLENGTH(direct) ((size_t) (direct)->d_namlen)
|
|
# if HAVE_SYS_NDIR_H
|
|
# include <sys/ndir.h>
|
|
# endif
|
|
# if HAVE_SYS_DIR_H
|
|
# include <sys/dir.h>
|
|
# endif
|
|
# if HAVE_NDIR_H
|
|
# include <ndir.h>
|
|
# endif
|
|
#endif
|
|
|
|
#if CLOSEDIR_VOID
|
|
/* Fake a return value. */
|
|
# define CLOSEDIR(d) (closedir (d), 0)
|
|
#else
|
|
# define CLOSEDIR(d) closedir (d)
|
|
#endif
|
|
|
|
#if STDC_HEADERS
|
|
# include <stdlib.h>
|
|
#else
|
|
char *malloc ();
|
|
#endif
|
|
|
|
#if HAVE_DIRENT_H || HAVE_NDIR_H || HAVE_SYS_DIR_H || HAVE_SYS_NDIR_H
|
|
# define HAVE_DIR 1
|
|
#else
|
|
# define HAVE_DIR 0
|
|
#endif
|
|
|
|
#if HAVE_LIMITS_H
|
|
# include <limits.h>
|
|
#endif
|
|
#ifndef CHAR_BIT
|
|
#define CHAR_BIT 8
|
|
#endif
|
|
/* Upper bound on the string length of an integer converted to string.
|
|
302 / 1000 is ceil (log10 (2.0)). Subtract 1 for the sign bit;
|
|
add 1 for integer division truncation; add 1 more for a minus sign. */
|
|
#define INT_STRLEN_BOUND(t) ((sizeof (t) * CHAR_BIT - 1) * 302 / 1000 + 2)
|
|
|
|
/* ISDIGIT differs from isdigit, as follows:
|
|
- Its arg may be any int or unsigned int; it need not be an unsigned char.
|
|
- It's guaranteed to evaluate its argument exactly once.
|
|
- It's typically faster.
|
|
Posix 1003.2-1992 section 2.5.2.1 page 50 lines 1556-1558 says that
|
|
only '0' through '9' are digits. Prefer ISDIGIT to isdigit unless
|
|
it's important to use the locale's definition of `digit' even when the
|
|
host does not conform to Posix. */
|
|
#define ISDIGIT(c) ((unsigned) (c) - '0' <= 9)
|
|
|
|
#if D_INO_IN_DIRENT
|
|
# define REAL_DIR_ENTRY(dp) ((dp)->d_ino != 0)
|
|
#else
|
|
# define REAL_DIR_ENTRY(dp) 1
|
|
#endif
|
|
|
|
/* Which type of backup file names are generated. */
|
|
enum backup_type backup_type = none;
|
|
|
|
/* The extension added to file names to produce a simple (as opposed
|
|
to numbered) backup file name. */
|
|
const char *simple_backup_suffix = ".orig";
|
|
|
|
static int max_backup_version __BACKUPFILE_P ((const char *, const char *));
|
|
static int version_number __BACKUPFILE_P ((const char *, const char *, size_t));
|
|
|
|
/* Return the name of the new backup file for file FILE,
|
|
allocated with malloc. Return 0 if out of memory.
|
|
FILE must not end with a '/' unless it is the root directory.
|
|
Do not call this function if backup_type == none. */
|
|
|
|
char *
|
|
find_backup_file_name (file)
|
|
const char *file;
|
|
{
|
|
size_t backup_suffix_size_max;
|
|
size_t file_len = strlen (file);
|
|
size_t numbered_suffix_size_max = INT_STRLEN_BOUND (int) + 4;
|
|
char *s;
|
|
const char *suffix = simple_backup_suffix;
|
|
|
|
/* Allow room for simple or `.~N~' backups. */
|
|
backup_suffix_size_max = strlen (simple_backup_suffix) + 1;
|
|
if (HAVE_DIR && backup_suffix_size_max < numbered_suffix_size_max)
|
|
backup_suffix_size_max = numbered_suffix_size_max;
|
|
|
|
s = malloc (file_len + backup_suffix_size_max + numbered_suffix_size_max);
|
|
if (s)
|
|
{
|
|
strcpy (s, file);
|
|
|
|
#if HAVE_DIR
|
|
if (backup_type != simple)
|
|
{
|
|
int highest_backup;
|
|
size_t dir_len = base_name (s) - s;
|
|
|
|
strcpy (s + dir_len, ".");
|
|
highest_backup = max_backup_version (file + dir_len, s);
|
|
if (! (backup_type == numbered_existing && highest_backup == 0))
|
|
{
|
|
char *numbered_suffix = s + (file_len + backup_suffix_size_max);
|
|
sprintf (numbered_suffix, ".~%d~", highest_backup + 1);
|
|
suffix = numbered_suffix;
|
|
}
|
|
strcpy (s, file);
|
|
}
|
|
#endif /* HAVE_DIR */
|
|
|
|
addext (s, suffix, '~');
|
|
}
|
|
return s;
|
|
}
|
|
|
|
#if HAVE_DIR
|
|
|
|
/* Return the number of the highest-numbered backup file for file
|
|
FILE in directory DIR. If there are no numbered backups
|
|
of FILE in DIR, or an error occurs reading DIR, return 0.
|
|
*/
|
|
|
|
static int
|
|
max_backup_version (file, dir)
|
|
const char *file;
|
|
const char *dir;
|
|
{
|
|
DIR *dirp;
|
|
struct dirent *dp;
|
|
int highest_version;
|
|
int this_version;
|
|
size_t file_name_length;
|
|
|
|
dirp = opendir (dir);
|
|
if (!dirp)
|
|
return 0;
|
|
|
|
highest_version = 0;
|
|
file_name_length = strlen (file);
|
|
|
|
while ((dp = readdir (dirp)) != 0)
|
|
{
|
|
if (!REAL_DIR_ENTRY (dp) || NLENGTH (dp) < file_name_length + 4)
|
|
continue;
|
|
|
|
this_version = version_number (file, dp->d_name, file_name_length);
|
|
if (this_version > highest_version)
|
|
highest_version = this_version;
|
|
}
|
|
if (CLOSEDIR (dirp))
|
|
return 0;
|
|
return highest_version;
|
|
}
|
|
|
|
/* If BACKUP is a numbered backup of BASE, return its version number;
|
|
otherwise return 0. BASE_LENGTH is the length of BASE.
|
|
*/
|
|
|
|
static int
|
|
version_number (base, backup, base_length)
|
|
const char *base;
|
|
const char *backup;
|
|
size_t base_length;
|
|
{
|
|
int version;
|
|
const char *p;
|
|
|
|
version = 0;
|
|
if (strncmp (base, backup, base_length) == 0
|
|
&& backup[base_length] == '.'
|
|
&& backup[base_length + 1] == '~')
|
|
{
|
|
for (p = &backup[base_length + 2]; ISDIGIT (*p); ++p)
|
|
version = version * 10 + *p - '0';
|
|
if (p[0] != '~' || p[1])
|
|
version = 0;
|
|
}
|
|
return version;
|
|
}
|
|
#endif /* HAVE_DIR */
|
|
|
|
static const char * const backup_args[] =
|
|
{
|
|
"never", "simple", "nil", "existing", "t", "numbered", 0
|
|
};
|
|
|
|
static const enum backup_type backup_types[] =
|
|
{
|
|
simple, simple, numbered_existing, numbered_existing, numbered, numbered
|
|
};
|
|
|
|
/* Return the type of backup indicated by VERSION.
|
|
Unique abbreviations are accepted. */
|
|
|
|
enum backup_type
|
|
get_version (version)
|
|
const char *version;
|
|
{
|
|
int i;
|
|
|
|
if (version == 0 || *version == 0)
|
|
return numbered_existing;
|
|
i = argmatch (version, backup_args);
|
|
if (i < 0)
|
|
{
|
|
invalid_arg ("version control type", version, i);
|
|
exit (2);
|
|
}
|
|
return backup_types[i];
|
|
}
|