/*- * 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("$FreeBSD$"); #include <sys/param.h> #include <sys/stat.h> #include <err.h> #include <errno.h> #include <fcntl.h> #include <libgen.h> #include <limits.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> static int fflag; /* Unlink existing files. */ static int Fflag; /* Remove empty directories also. */ static int hflag; /* Check new name for symlink first. */ static int iflag; /* Interactive mode. */ static int Pflag; /* Create hard links to symlinks. */ static int sflag; /* Symbolic, not hard, link. */ static int vflag; /* Verbose output. */ static int wflag; /* Warn if symlink target does not * exist, and -f is not enabled. */ static char linkch; static int linkit(const char *, const char *, int); static void usage(void); int main(int argc, char *argv[]) { struct stat sb; char *p, *targetdir; 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 = strrchr(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(); exit(linkit(argv[0], argv[1], 0)); } while ((ch = getopt(argc, argv, "FLPfhinsvw")) != -1) switch (ch) { case 'F': Fflag = 1; break; case 'L': Pflag = 0; break; case 'P': Pflag = 1; break; case 'f': fflag = 1; iflag = 0; wflag = 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 'w': wflag = 1; break; case '?': default: usage(); } argv += optind; argc -= optind; linkch = sflag ? '-' : '='; if (sflag == 0) Fflag = 0; if (Fflag == 1 && iflag == 0) { fflag = 1; wflag = 0; /* Implied when fflag != 0 */ } switch(argc) { case 0: usage(); /* NOTREACHED */ case 1: /* ln source */ exit(linkit(argv[0], ".", 1)); case 2: /* ln source target */ exit(linkit(argv[0], argv[1], 0)); default: ; } /* ln source1 source2 directory */ targetdir = argv[argc - 1]; if (hflag && lstat(targetdir, &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", targetdir); } if (stat(targetdir, &sb)) err(1, "%s", targetdir); if (!S_ISDIR(sb.st_mode)) usage(); for (exitval = 0; *argv != targetdir; ++argv) exitval |= linkit(*argv, targetdir, 1); exit(exitval); } /* * Two pathnames refer to the same directory entry if the directories match * and the final components' names match. */ static int samedirent(const char *path1, const char *path2) { const char *file1, *file2; char pathbuf[PATH_MAX]; struct stat sb1, sb2; if (strcmp(path1, path2) == 0) return 1; file1 = strrchr(path1, '/'); if (file1 != NULL) file1++; else file1 = path1; file2 = strrchr(path2, '/'); if (file2 != NULL) file2++; else file2 = path2; if (strcmp(file1, file2) != 0) return 0; if (file1 - path1 >= PATH_MAX || file2 - path2 >= PATH_MAX) return 0; if (file1 == path1) memcpy(pathbuf, ".", 2); else { memcpy(pathbuf, path1, file1 - path1); pathbuf[file1 - path1] = '\0'; } if (stat(pathbuf, &sb1) != 0) return 0; if (file2 == path2) memcpy(pathbuf, ".", 2); else { memcpy(pathbuf, path2, file2 - path2); pathbuf[file2 - path2] = '\0'; } if (stat(pathbuf, &sb2) != 0) return 0; return sb1.st_dev == sb2.st_dev && sb1.st_ino == sb2.st_ino; } static int linkit(const char *source, const char *target, int isdir) { struct stat sb; const char *p; int ch, exists, first; char path[PATH_MAX]; char wbuf[PATH_MAX]; char bbuf[PATH_MAX]; if (!sflag) { /* If source doesn't exist, quit now. */ if ((Pflag ? lstat : stat)(source, &sb)) { warn("%s", source); return (1); } /* Only symbolic links to directories. */ if (S_ISDIR(sb.st_mode)) { errno = EISDIR; warn("%s", source); return (1); } } /* * If the target is a directory (and not a symlink if hflag), * append the source's name. */ if (isdir || (lstat(target, &sb) == 0 && S_ISDIR(sb.st_mode)) || (!hflag && stat(target, &sb) == 0 && S_ISDIR(sb.st_mode))) { if (strlcpy(bbuf, source, sizeof(bbuf)) >= sizeof(bbuf) || (p = basename(bbuf)) == NULL || snprintf(path, sizeof(path), "%s/%s", target, p) >= (ssize_t)sizeof(path)) { errno = ENAMETOOLONG; warn("%s", source); return (1); } target = path; } /* * If the link source doesn't exist, and a symbolic link was * requested, and -w was specified, give a warning. */ if (sflag && wflag) { if (*source == '/') { /* Absolute link source. */ if (stat(source, &sb) != 0) warn("warning: %s inaccessible", source); } else { /* * Relative symlink source. Try to construct the * absolute path of the source, by appending `source' * to the parent directory of the target. */ strlcpy(bbuf, target, sizeof(bbuf)); p = dirname(bbuf); if (p != NULL) { (void)snprintf(wbuf, sizeof(wbuf), "%s/%s", p, source); if (stat(wbuf, &sb) != 0) warn("warning: %s", source); } } } /* * If the file exists, first check it is not the same directory entry. */ exists = !lstat(target, &sb); if (exists) { if (!sflag && samedirent(source, target)) { warnx("%s and %s are the same directory entry", source, target); return (1); } } /* * 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(target)) { warn("%s", target); return (1); } } else if (unlink(target)) { warn("%s", target); return (1); } } else if (iflag && exists) { fflush(stdout); fprintf(stderr, "replace %s? ", target); 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(target)) { warn("%s", target); return (1); } } else if (unlink(target)) { warn("%s", target); return (1); } } /* Attempt the link. */ if (sflag ? symlink(source, target) : linkat(AT_FDCWD, source, AT_FDCWD, target, Pflag ? 0 : AT_SYMLINK_FOLLOW)) { warn("%s", target); return (1); } if (vflag) (void)printf("%s %c> %s\n", target, linkch, source); return (0); } static void usage(void) { (void)fprintf(stderr, "%s\n%s\n%s\n", "usage: ln [-s [-F] | -L | -P] [-f | -i] [-hnv] source_file [target_file]", " ln [-s [-F] | -L | -P] [-f | -i] [-hnv] source_file ... target_dir", " link source_file target_file"); exit(1); }