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|
/* ln - make links */
/* See Makefile for compilation details. */
/*
Copyright (C) 1999-2009 Free Software Foundation, Inc.
This file is part of GNU Bash.
Bash 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 of the License, or
(at your option) any later version.
Bash 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 Bash. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "bashtypes.h"
#if defined (HAVE_UNISTD_H)
# include <unistd.h>
#endif
#include "posixstat.h"
#include <stdio.h>
#include <errno.h>
#include "builtins.h"
#include "shell.h"
#include "bashgetopt.h"
#include "common.h"
#if !defined (errno)
extern int errno;
#endif
typedef int unix_link_syscall_t __P((const char *, const char *));
#define LN_SYMLINK 0x01
#define LN_UNLINK 0x02
#define LN_NOFOLLOW 0x04
static unix_link_syscall_t *linkfn;
static int dolink ();
int
ln_builtin (list)
WORD_LIST *list;
{
int rval, opt, flags;
WORD_LIST *l;
char *sdir;
struct stat sb;
flags = 0;
reset_internal_getopt ();
while ((opt = internal_getopt (list, "fs")) != -1)
{
switch (opt)
{
case 'f':
flags |= LN_UNLINK;
break;
case 's':
flags |= LN_SYMLINK;
break;
case 'h':
case 'n':
flags |= LN_NOFOLLOW;
break;
CASE_HELPOPT;
default:
builtin_usage ();
return (EX_USAGE);
}
}
list = loptend;
if (list == 0)
{
builtin_usage ();
return (EX_USAGE);
}
linkfn = (flags & LN_SYMLINK) ? symlink : link;
if (list->next == 0) /* ln target, equivalent to ln target . */
return (dolink (list->word->word, ".", flags));
if (list->next->next == 0) /* ln target source */
return (dolink (list->word->word, list->next->word->word, flags));
/* ln target1 target2 ... directory */
/* find last argument: target directory, and make sure it's an existing
directory. */
for (l = list; l->next; l = l->next)
;
sdir = l->word->word;
if (stat(sdir, &sb) < 0)
{
builtin_error ("%s", sdir);
return (EXECUTION_FAILURE);
}
if (S_ISDIR (sb.st_mode) == 0)
{
builtin_usage ();
return (EX_USAGE);
}
for (rval = EXECUTION_SUCCESS; list != l; list = list->next)
rval += dolink (list->word->word, sdir, flags);
return rval;
}
static char *
mkdirpath (dir, file)
char *dir, *file;
{
int dlen, flen;
char *ret;
dlen = strlen (dir);
flen = strlen (file);
ret = xmalloc (2 + dlen + flen);
strcpy (ret, dir);
if (ret[dlen - 1] != '/')
ret[dlen++] = '/';
strcpy (ret + dlen, file);
return ret;
}
#if defined (HAVE_LSTAT)
# define LSTAT lstat
# define LSTAT_OR_STAT_IF(c, f, b) ((c) ? lstat((f), (b)) : stat((f), (b)))
#else
# define LSTAT stat
# define LSTAT_OR_STAT_IF(c, f, b) (stat((f), (b)))
#endif
static int
dolink (src, dst, flags)
char *src, *dst;
int flags;
{
struct stat ssb, dsb;
int exists;
char *dst_path, *p;
/* If we're not doing symlinks, the source must exist and not be a
directory. */
if ((flags & LN_SYMLINK) == 0)
{
if (stat (src, &ssb) != 0)
{
builtin_error ("%s: %s", src, strerror (errno));
return (EXECUTION_FAILURE);
}
if (S_ISDIR (ssb.st_mode))
{
errno = EISDIR;
builtin_error ("%s: %s", src, strerror (errno));
return (EXECUTION_FAILURE);
}
}
/* If the destination is a directory, create the final filename by appending
the basename of the source to the destination. */
dst_path = 0;
if ((LSTAT_OR_STAT_IF((flags & LN_NOFOLLOW), dst, &dsb) == 0) && S_ISDIR (dsb.st_mode))
{
if ((p = strrchr (src, '/')) == 0)
p = src;
else
p++;
dst_path = mkdirpath (dst, p);
dst = dst_path;
}
exists = LSTAT (dst, &dsb) == 0;
/* If -f was specified, and the destination exists, unlink it. */
if ((flags & LN_UNLINK) && exists && unlink (dst) != 0)
{
builtin_error ("%s: cannot unlink: %s", dst, strerror (errno));
FREE (dst_path);
return (EXECUTION_FAILURE);
}
/* Perform the link. */
if ((*linkfn) (src, dst) != 0)
{
builtin_error ("cannot link %s to %s: %s", dst, src, strerror (errno));
FREE (dst_path);
return (EXECUTION_FAILURE);
}
FREE (dst_path);
return (EXECUTION_SUCCESS);
}
char *ln_doc[] = {
"Link files.",
"",
"Create a new directory entry with the same modes as the original",
"file. The -f option means to unlink any existing file, permitting",
"the link to occur. The -s option means to create a symbolic link.",
"By default, ln makes hard links. Specifying -n or its synonym -h",
"causes ln to not resolve symlinks in the target file or directory.",
(char *)NULL
};
/* The standard structure describing a builtin command. bash keeps an array
of these structures. */
struct builtin ln_struct = {
"ln", /* builtin name */
ln_builtin, /* function implementing the builtin */
BUILTIN_ENABLED, /* initial flags for builtin */
ln_doc, /* array of long documentation strings. */
"ln [-fhns] file1 [file2] OR ln [-fhns] file ... directory", /* usage synopsis; becomes short_doc */
0 /* reserved for internal use */
};
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