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/* `ln' program to create links between files.
Copyright (C) 1986, 1989, 1990, 1991 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; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* Written by Mike Parker and David MacKenzie. */
#ifdef _AIX
#pragma alloca
#endif
#include <stdio.h>
#include <sys/types.h>
#include <getopt.h>
#include "system.h"
#include "backupfile.h"
#include "version.h"
int link (); /* Some systems don't declare this anywhere. */
#ifdef S_ISLNK
int symlink ();
#endif
char *basename ();
enum backup_type get_version ();
int isdir ();
int yesno ();
void error ();
static void usage ();
static int do_link ();
/* The name by which the program was run, for error messages. */
char *program_name;
/* A pointer to the function used to make links. This will point to either
`link' or `symlink'. */
static int (*linkfunc) ();
/* If nonzero, make symbolic links; otherwise, make hard links. */
static int symbolic_link;
/* If nonzero, ask the user before removing existing files. */
static int interactive;
/* If nonzero, remove existing files unconditionally. */
static int remove_existing_files;
/* If nonzero, list each file as it is moved. */
static int verbose;
/* If nonzero, allow the superuser to make hard links to directories. */
static int hard_dir_link;
/* If non-zero, display usage information and exit. */
static int flag_help;
/* If non-zero, print the version on standard error. */
static int flag_version;
static struct option const long_options[] =
{
{"backup", no_argument, NULL, 'b'},
{"directory", no_argument, &hard_dir_link, 1},
{"force", no_argument, NULL, 'f'},
{"interactive", no_argument, NULL, 'i'},
{"suffix", required_argument, NULL, 'S'},
{"symbolic", no_argument, &symbolic_link, 1},
{"verbose", no_argument, &verbose, 1},
{"version-control", required_argument, NULL, 'V'},
{"help", no_argument, &flag_help, 1},
{"version", no_argument, &flag_version, 1},
{NULL, 0, NULL, 0}
};
void
main (argc, argv)
int argc;
char **argv;
{
int c;
int errors;
int make_backups = 0;
char *version;
version = getenv ("SIMPLE_BACKUP_SUFFIX");
if (version)
simple_backup_suffix = version;
version = getenv ("VERSION_CONTROL");
program_name = argv[0];
linkfunc = link;
symbolic_link = remove_existing_files = interactive = verbose
= hard_dir_link = 0;
errors = 0;
while ((c = getopt_long (argc, argv, "bdfisvFS:V:", long_options, (int *) 0))
!= EOF)
{
switch (c)
{
case 0: /* Long-named option. */
break;
case 'b':
make_backups = 1;
break;
case 'd':
case 'F':
hard_dir_link = 1;
break;
case 'f':
remove_existing_files = 1;
interactive = 0;
break;
case 'i':
remove_existing_files = 0;
interactive = 1;
break;
case 's':
#ifdef S_ISLNK
symbolic_link = 1;
#else
error (1, 0, "symbolic links are not supported on this system");
#endif
break;
case 'v':
verbose = 1;
break;
case 'S':
simple_backup_suffix = optarg;
break;
case 'V':
version = optarg;
break;
default:
usage ();
break;
}
}
if (flag_version)
fprintf (stderr, "%s\n", version_string);
if (flag_help)
usage ();
if (optind == argc)
usage ();
if (make_backups)
backup_type = get_version (version);
#ifdef S_ISLNK
if (symbolic_link)
linkfunc = symlink;
#endif
if (optind == argc - 1)
errors = do_link (argv[optind], ".");
else if (optind == argc - 2)
{
errors = do_link (argv[optind], argv[optind + 1]);
}
else
{
char *to;
to = argv[argc - 1];
if (!isdir (to))
error (1, 0, "when making multiple links, last argument must be a directory");
for (; optind < argc - 1; ++optind)
errors += do_link (argv[optind], to);
}
exit (errors != 0);
}
/* Make a link DEST to existing file SOURCE.
If DEST is a directory, put the link to SOURCE in that directory.
Return 1 if there is an error, otherwise 0. */
static int
do_link (source, dest)
char *source;
char *dest;
{
struct stat dest_stats;
char *dest_backup = NULL;
/* isdir uses stat instead of lstat.
On SVR4, link does not follow symlinks, so this check disallows
making hard links to symlinks that point to directories. Big deal.
On other systems, link follows symlinks, so this check is right. */
if (!symbolic_link && !hard_dir_link && isdir (source))
{
error (0, 0, "%s: hard link not allowed for directory", source);
return 1;
}
if (isdir (dest))
{
/* Target is a directory; build the full filename. */
char *new_dest;
char *source_base;
source_base = basename (source);
new_dest = (char *)
alloca (strlen (source_base) + 1 + strlen (dest) + 1);
sprintf (new_dest, "%s/%s", dest, source_base);
dest = new_dest;
}
if (lstat (dest, &dest_stats) == 0)
{
if (S_ISDIR (dest_stats.st_mode))
{
error (0, 0, "%s: cannot overwrite directory", dest);
return 1;
}
if (interactive)
{
fprintf (stderr, "%s: replace `%s'? ", program_name, dest);
if (!yesno ())
return 0;
}
else if (!remove_existing_files)
{
error (0, 0, "%s: File exists", dest);
return 1;
}
if (backup_type != none)
{
char *tmp_backup = find_backup_file_name (dest);
if (tmp_backup == NULL)
error (1, 0, "virtual memory exhausted");
dest_backup = alloca (strlen (tmp_backup) + 1);
strcpy (dest_backup, tmp_backup);
free (tmp_backup);
if (rename (dest, dest_backup))
{
if (errno != ENOENT)
{
error (0, errno, "cannot backup `%s'", dest);
return 1;
}
else
dest_backup = NULL;
}
}
else if (unlink (dest) && errno != ENOENT)
{
error (0, errno, "cannot remove old link to `%s'", dest);
return 1;
}
}
else if (errno != ENOENT)
{
error (0, errno, "%s", dest);
return 1;
}
if (verbose)
printf ("%s -> %s\n", source, dest);
if ((*linkfunc) (source, dest) == 0)
{
return 0;
}
error (0, errno, "cannot %slink `%s' to `%s'",
#ifdef S_ISLNK
linkfunc == symlink ? "symbolic " : "",
#else
"",
#endif
source, dest);
if (dest_backup)
{
if (rename (dest_backup, dest))
error (0, errno, "cannot un-backup `%s'", dest);
}
return 1;
}
static void
usage ()
{
fprintf (stderr, "\
Usage: %s [options] source [dest]\n\
%s [options] source... directory\n\
Options:\n\
[-bdfisvF] [-S backup-suffix] [-V {numbered,existing,simple}]\n\
[--version-control={numbered,existing,simple}] [--backup] [--directory]\n\
[--force] [--interactive] [--symbolic] [--verbose]\n\
[--suffix=backup-suffix] [--help] [--version]\n",
program_name, program_name);
exit (1);
}
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