freebsd-dev/bin/ln/ln.c
2003-05-01 16:58:57 +00:00

248 lines
6.1 KiB
C

/*
* Copyright (c) 1987, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if 0
#ifndef lint
static char const copyright[] =
"@(#) Copyright (c) 1987, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)ln.c 8.2 (Berkeley) 3/31/94";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/stat.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
int fflag; /* Unlink existing files. */
int hflag; /* Check new name for symlink first. */
int iflag; /* Interactive mode. */
int sflag; /* Symbolic, not hard, link. */
int vflag; /* Verbose output. */
/* System link call. */
int (*linkf)(const char *, const char *);
char linkch;
int linkit(const char *, const char *, int);
void usage(void);
int
main(int argc, char *argv[])
{
struct stat sb;
char *p, *sourcedir;
int ch, exitval;
/*
* Test for the special case where the utility is called as
* "link", for which the functionality provided is greatly
* simplified.
*/
if ((p = rindex(argv[0], '/')) == NULL)
p = argv[0];
else
++p;
if (strcmp(p, "link") == 0) {
while (getopt(argc, argv, "") != -1)
usage();
argc -= optind;
argv += optind;
if (argc != 2)
usage();
linkf = link;
exit(linkit(argv[0], argv[1], 0));
}
while ((ch = getopt(argc, argv, "fhinsv")) != -1)
switch (ch) {
case 'f':
fflag = 1;
iflag = 0;
break;
case 'h':
case 'n':
hflag = 1;
break;
case 'i':
iflag = 1;
fflag = 0;
break;
case 's':
sflag = 1;
break;
case 'v':
vflag = 1;
break;
case '?':
default:
usage();
}
argv += optind;
argc -= optind;
linkf = sflag ? symlink : link;
linkch = sflag ? '-' : '=';
switch(argc) {
case 0:
usage();
/* NOTREACHED */
case 1: /* ln target */
exit(linkit(argv[0], ".", 1));
case 2: /* ln target source */
exit(linkit(argv[0], argv[1], 0));
default:
;
}
/* ln target1 target2 directory */
sourcedir = argv[argc - 1];
if (hflag && lstat(sourcedir, &sb) == 0 && S_ISLNK(sb.st_mode)) {
/*
* We were asked not to follow symlinks, but found one at
* the target--simulate "not a directory" error
*/
errno = ENOTDIR;
err(1, "%s", sourcedir);
}
if (stat(sourcedir, &sb))
err(1, "%s", sourcedir);
if (!S_ISDIR(sb.st_mode))
usage();
for (exitval = 0; *argv != sourcedir; ++argv)
exitval |= linkit(*argv, sourcedir, 1);
exit(exitval);
}
int
linkit(const char *target, const char *source, int isdir)
{
struct stat sb;
const char *p;
int ch, exists, first;
char path[PATH_MAX];
if (!sflag) {
/* If target doesn't exist, quit now. */
if (stat(target, &sb)) {
warn("%s", target);
return (1);
}
/* Only symbolic links to directories. */
if (S_ISDIR(sb.st_mode)) {
errno = EISDIR;
warn("%s", target);
return (1);
}
}
/*
* If the source is a directory (and not a symlink if hflag),
* append the target's name.
*/
if (isdir ||
(lstat(source, &sb) == 0 && S_ISDIR(sb.st_mode)) ||
(!hflag && stat(source, &sb) == 0 && S_ISDIR(sb.st_mode))) {
if ((p = strrchr(target, '/')) == NULL)
p = target;
else
++p;
if (snprintf(path, sizeof(path), "%s/%s", source, p) >=
(ssize_t)sizeof(path)) {
errno = ENAMETOOLONG;
warn("%s", target);
return (1);
}
source = path;
}
exists = !lstat(source, &sb);
/*
* If the file exists, then unlink it forcibly if -f was specified
* and interactively if -i was specified.
*/
if (fflag && exists) {
if (unlink(source)) {
warn("%s", source);
return (1);
}
} else if (iflag && exists) {
fflush(stdout);
fprintf(stderr, "replace %s? ", source);
first = ch = getchar();
while(ch != '\n' && ch != EOF)
ch = getchar();
if (first != 'y' && first != 'Y') {
fprintf(stderr, "not replaced\n");
return (1);
}
if (unlink(source)) {
warn("%s", source);
return (1);
}
}
/* Attempt the link. */
if ((*linkf)(target, source)) {
warn("%s", source);
return (1);
}
if (vflag)
(void)printf("%s %c> %s\n", source, linkch, target);
return (0);
}
void
usage(void)
{
(void)fprintf(stderr, "%s\n%s\n%s\n",
"usage: ln [-fhinsv] file1 file2",
" ln [-fhinsv] file ... directory",
" link file1 file2");
exit(1);
}