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Diffstat (limited to 'bin/ln/ln.c')
| -rw-r--r-- | bin/ln/ln.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/bin/ln/ln.c b/bin/ln/ln.c new file mode 100644 index 0000000..b39e710 --- /dev/null +++ b/bin/ln/ln.c @@ -0,0 +1,164 @@ +/* + * 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. + */ + +#ifndef lint +static char 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 */ + +#include <sys/param.h> +#include <sys/stat.h> + +#include <err.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +int dirflag; /* Undocumented directory flag. */ +int fflag; /* Unlink existing files. */ +int sflag; /* Symbolic, not hard, link. */ + /* System link call. */ +int (*linkf) __P((const char *, const char *)); + +int linkit __P((char *, char *, int)); +void usage __P((void)); + +int +main(argc, argv) + int argc; + char *argv[]; +{ + extern int optind; + struct stat sb; + int ch, exitval; + char *sourcedir; + + while ((ch = getopt(argc, argv, "Ffs")) != EOF) + switch (ch) { + case 'F': + dirflag = 1; /* XXX: deliberately undocumented. */ + break; + case 'f': + fflag = 1; + break; + case 's': + sflag = 1; + break; + case '?': + default: + usage(); + } + + argv += optind; + argc -= optind; + + linkf = sflag ? symlink : link; + + switch(argc) { + case 0: + usage(); + case 1: /* ln target */ + exit(linkit(argv[0], ".", 1)); + case 2: /* ln target source */ + exit(linkit(argv[0], argv[1], 0)); + } + /* ln target1 target2 directory */ + sourcedir = argv[argc - 1]; + 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(target, source, isdir) + char *target, *source; + int isdir; +{ + struct stat sb; + int exists; + char *p, path[MAXPATHLEN]; + + if (!sflag) { + /* If target doesn't exist, quit now. */ + if (stat(target, &sb)) { + warn("%s", target); + return (1); + } + /* Only symbolic links to directories, unless -F option used. */ + if (!dirflag && (sb.st_mode & S_IFMT) == S_IFDIR) { + warnx("%s: is a directory", target); + return (1); + } + } + + /* If the source is a directory, append the target's name. */ + if (isdir || (exists = !stat(source, &sb)) && S_ISDIR(sb.st_mode)) { + if ((p = strrchr(target, '/')) == NULL) + p = target; + else + ++p; + (void)snprintf(path, sizeof(path), "%s/%s", source, p); + source = path; + exists = !stat(source, &sb); + } else + exists = !stat(source, &sb); + + /* + * If the file exists, and -f was specified, unlink it. + * Attempt the link. + */ + if (fflag && exists && unlink(source) || (*linkf)(target, source)) { + warn("%s", source); + return (1); + } + return (0); +} + +void +usage() +{ + (void)fprintf(stderr, + "usage:\tln [-fs] file1 file2\n\tln [-fs] file ... directory\n"); + exit(1); +} |
