diff options
Diffstat (limited to 'file_cmds/ln/ln.c')
| -rw-r--r-- | file_cmds/ln/ln.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/file_cmds/ln/ln.c b/file_cmds/ln/ln.c new file mode 100644 index 0000000..0455dce --- /dev/null +++ b/file_cmds/ln/ln.c @@ -0,0 +1,272 @@ +/*- + * 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. + * 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: src/bin/ln/ln.c,v 1.34 2006/02/14 11:08:05 glebius Exp $"); + +#include <sys/param.h> +#include <sys/stat.h> + +#include <err.h> +#include <errno.h> +#include <libgen.h> +#include <limits.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +int fflag; /* Unlink existing files. */ +int Fflag; /* Remove empty directories also. */ +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; + + if (argc < 1) + usage(); + /* + * 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; + /* UNIX conformance requires that both operands be NOT a dir */ + for (int i = 0; i < 2; i++) { + if (stat(argv[i], &sb) == 0 && S_ISDIR(sb.st_mode)){ + errno = EISDIR; + warn("%s", argv[0]); + return 1; + } + } + + exit(linkit(argv[0], argv[1], 0)); + } + + while ((ch = getopt(argc, argv, "Ffhinsv")) != -1) + switch (ch) { + case 'F': + Fflag = 1; + break; + 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 ? '-' : '='; + if (sflag == 0) + Fflag = 0; + if (Fflag == 1 && iflag == 0) + fflag = 1; + + 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]; + char bbuf[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 (strlcpy(bbuf, target, sizeof(bbuf)) >= sizeof(bbuf) || + (p = basename(bbuf)) == NULL || + 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 (Fflag && S_ISDIR(sb.st_mode)) { + if (rmdir(source)) { + warn("%s", source); + return (1); + } + } else 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 (Fflag && S_ISDIR(sb.st_mode)) { + if (rmdir(source)) { + warn("%s", source); + return (1); + } + } else 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 [-Ffhinsv] source_file [link_name]", + " ln [-Ffhinsv] source_file ... linkname_dir", + " link source_file link_name"); + exit(1); +} |