Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1 | /* vi: set sw=4 ts=4: */ |
Eric Andersen | f6be944 | 1999-10-13 21:12:06 +0000 | [diff] [blame] | 2 | /* |
| 3 | * Mini ln implementation for busybox |
| 4 | * |
Eric Andersen | c7bda1c | 2004-03-15 08:29:22 +0000 | [diff] [blame] | 5 | * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> |
Eric Andersen | f6be944 | 1999-10-13 21:12:06 +0000 | [diff] [blame] | 6 | * |
Denys Vlasenko | 0ef64bd | 2010-08-16 20:14:46 +0200 | [diff] [blame] | 7 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
Eric Andersen | f6be944 | 1999-10-13 21:12:06 +0000 | [diff] [blame] | 8 | */ |
Denys Vlasenko | af3f420 | 2016-11-23 14:46:56 +0100 | [diff] [blame] | 9 | //config:config LN |
Denys Vlasenko | b097a84 | 2018-12-28 03:20:17 +0100 | [diff] [blame] | 10 | //config: bool "ln (4.9 kb)" |
Denys Vlasenko | af3f420 | 2016-11-23 14:46:56 +0100 | [diff] [blame] | 11 | //config: default y |
| 12 | //config: help |
Denys Vlasenko | 72089cf | 2017-07-21 09:50:55 +0200 | [diff] [blame] | 13 | //config: ln is used to create hard or soft links between files. |
Denys Vlasenko | af3f420 | 2016-11-23 14:46:56 +0100 | [diff] [blame] | 14 | |
| 15 | //applet:IF_LN(APPLET_NOEXEC(ln, ln, BB_DIR_BIN, BB_SUID_DROP, ln)) |
| 16 | |
| 17 | //kbuild:lib-$(CONFIG_LN) += ln.o |
Eric Andersen | f6be944 | 1999-10-13 21:12:06 +0000 | [diff] [blame] | 18 | |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 19 | /* BB_AUDIT SUSv3 compliant */ |
Rob Landley | 3071e2f | 2005-04-29 22:13:04 +0000 | [diff] [blame] | 20 | /* BB_AUDIT GNU options missing: -d, -F, -i, and -v. */ |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 21 | /* http://www.opengroup.org/onlinepubs/007904975/utilities/ln.html */ |
| 22 | |
Pere Orga | 3442538 | 2011-03-31 14:43:25 +0200 | [diff] [blame] | 23 | //usage:#define ln_trivial_usage |
Denys Vlasenko | 84d5edd | 2020-12-13 22:34:05 +0100 | [diff] [blame^] | 24 | //usage: "[-sfnbtv] [-S SUF] TARGET... LINK|DIR" |
Pere Orga | 3442538 | 2011-03-31 14:43:25 +0200 | [diff] [blame] | 25 | //usage:#define ln_full_usage "\n\n" |
| 26 | //usage: "Create a link LINK or DIR/TARGET to the specified TARGET(s)\n" |
Pere Orga | 3442538 | 2011-03-31 14:43:25 +0200 | [diff] [blame] | 27 | //usage: "\n -s Make symlinks instead of hardlinks" |
| 28 | //usage: "\n -f Remove existing destinations" |
| 29 | //usage: "\n -n Don't dereference symlinks - treat like normal file" |
| 30 | //usage: "\n -b Make a backup of the target (if exists) before link operation" |
Denys Vlasenko | 84d5edd | 2020-12-13 22:34:05 +0100 | [diff] [blame^] | 31 | //usage: "\n -S SUF Use suffix instead of ~ when making backup files" |
John L. Hammond | 94f607a | 2019-05-09 09:22:09 -0500 | [diff] [blame] | 32 | //usage: "\n -T Treat LINK as a file, not DIR" |
Simon B | 44642d1 | 2012-05-06 13:18:35 +0200 | [diff] [blame] | 33 | //usage: "\n -v Verbose" |
Pere Orga | 3442538 | 2011-03-31 14:43:25 +0200 | [diff] [blame] | 34 | //usage: |
| 35 | //usage:#define ln_example_usage |
| 36 | //usage: "$ ln -s BusyBox /tmp/ls\n" |
| 37 | //usage: "$ ls -l /tmp/ls\n" |
| 38 | //usage: "lrwxrwxrwx 1 root root 7 Apr 12 18:39 ls -> BusyBox*\n" |
| 39 | |
Denis Vlasenko | b6adbf1 | 2007-05-26 19:00:18 +0000 | [diff] [blame] | 40 | #include "libbb.h" |
Eric Andersen | cbe31da | 2001-02-20 06:14:08 +0000 | [diff] [blame] | 41 | |
Denis Vlasenko | 99912ca | 2007-04-10 15:43:37 +0000 | [diff] [blame] | 42 | /* This is a NOEXEC applet. Be very careful! */ |
| 43 | |
Simon B | 44642d1 | 2012-05-06 13:18:35 +0200 | [diff] [blame] | 44 | #define LN_SYMLINK (1 << 0) |
| 45 | #define LN_FORCE (1 << 1) |
| 46 | #define LN_NODEREFERENCE (1 << 2) |
| 47 | #define LN_BACKUP (1 << 3) |
| 48 | #define LN_SUFFIX (1 << 4) |
| 49 | #define LN_VERBOSE (1 << 5) |
| 50 | #define LN_LINKFILE (1 << 6) |
Eric Andersen | f6be944 | 1999-10-13 21:12:06 +0000 | [diff] [blame] | 51 | |
Denis Vlasenko | 9b49a5e | 2007-10-11 10:05:36 +0000 | [diff] [blame] | 52 | int ln_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
Rob Landley | dfba741 | 2006-03-06 20:47:33 +0000 | [diff] [blame] | 53 | int ln_main(int argc, char **argv) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 54 | { |
Eric Andersen | 13241df | 2000-10-04 16:02:53 +0000 | [diff] [blame] | 55 | int status = EXIT_SUCCESS; |
Denys Vlasenko | e992bae | 2009-11-28 15:18:53 +0100 | [diff] [blame] | 56 | int opts; |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 57 | char *last; |
| 58 | char *src_name; |
Glenn L McGrath | cfc0ad4 | 2003-12-31 23:10:44 +0000 | [diff] [blame] | 59 | char *src; |
Denis Vlasenko | a41fdf3 | 2007-01-29 22:51:00 +0000 | [diff] [blame] | 60 | char *suffix = (char*)"~"; |
Glenn L McGrath | cfc0ad4 | 2003-12-31 23:10:44 +0000 | [diff] [blame] | 61 | struct stat statbuf; |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 62 | int (*link_func)(const char *, const char *); |
| 63 | |
Denys Vlasenko | 22542ec | 2017-08-08 21:55:02 +0200 | [diff] [blame] | 64 | opts = getopt32(argv, "^" "sfnbS:vT" "\0" "-1", &suffix); |
Kaarle Ritvanen | 71b268c | 2019-10-08 14:07:50 +0200 | [diff] [blame] | 65 | /* |
| 66 | -s, --symbolic make symbolic links instead of hard links |
| 67 | -f, --force remove existing destination files |
| 68 | -n, --no-dereference treat LINK_NAME as a normal file if it is a symbolic link to a directory |
| 69 | -b like --backup but does not accept an argument |
| 70 | --backup[=CONTROL] make a backup of each existing destination file |
| 71 | -S, --suffix=SUFFIX override the usual backup suffix |
| 72 | -v, --verbose |
| 73 | -T, --no-target-directory |
| 74 | -d, -F, --directory allow the superuser to attempt to hard link directories |
| 75 | -i, --interactive prompt whether to remove destinations |
| 76 | -L, --logical dereference TARGETs that are symbolic links |
| 77 | -P, --physical make hard links directly to symbolic links |
| 78 | -r, --relative create symbolic links relative to link location |
| 79 | -t, --target-directory=DIRECTORY specify the DIRECTORY in which to create the links |
| 80 | */ |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 81 | last = argv[argc - 1]; |
| 82 | argv += optind; |
Simon B | 44642d1 | 2012-05-06 13:18:35 +0200 | [diff] [blame] | 83 | argc -= optind; |
| 84 | |
| 85 | if ((opts & LN_LINKFILE) && argc > 2) { |
James Byrne | 6937487 | 2019-07-02 11:35:03 +0200 | [diff] [blame] | 86 | bb_simple_error_msg_and_die("-T accepts 2 args max"); |
Simon B | 44642d1 | 2012-05-06 13:18:35 +0200 | [diff] [blame] | 87 | } |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 88 | |
Denys Vlasenko | b0e8ced | 2011-03-21 12:36:35 +0100 | [diff] [blame] | 89 | if (!argv[1]) { |
| 90 | /* "ln PATH/TO/FILE" -> "ln PATH/TO/FILE FILE" */ |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 91 | *--argv = last; |
Denys Vlasenko | b0e8ced | 2011-03-21 12:36:35 +0100 | [diff] [blame] | 92 | /* xstrdup is needed: "ln -s PATH/TO/FILE/" is equivalent to |
| 93 | * "ln -s PATH/TO/FILE/ FILE", not "ln -s PATH/TO/FILE FILE" |
| 94 | */ |
Denis Vlasenko | 818322b | 2007-09-24 18:27:04 +0000 | [diff] [blame] | 95 | last = bb_get_last_path_component_strip(xstrdup(last)); |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 96 | } |
| 97 | |
| 98 | do { |
Glenn L McGrath | cfc0ad4 | 2003-12-31 23:10:44 +0000 | [diff] [blame] | 99 | src_name = NULL; |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 100 | src = last; |
| 101 | |
| 102 | if (is_directory(src, |
Kaarle Ritvanen | 71b268c | 2019-10-08 14:07:50 +0200 | [diff] [blame] | 103 | /*followlinks:*/ !(opts & (LN_NODEREFERENCE|LN_LINKFILE)) |
| 104 | /* Why LN_LINKFILE does not follow links: |
| 105 | * -T/--no-target-directory implies -n/--no-dereference |
| 106 | */ |
| 107 | ) |
Denis Vlasenko | 6a2f7f4 | 2007-08-16 10:35:17 +0000 | [diff] [blame] | 108 | ) { |
Simon B | 44642d1 | 2012-05-06 13:18:35 +0200 | [diff] [blame] | 109 | if (opts & LN_LINKFILE) { |
| 110 | bb_error_msg_and_die("'%s' is a directory", src); |
| 111 | } |
Rob Landley | d921b2e | 2006-08-03 15:41:12 +0000 | [diff] [blame] | 112 | src_name = xstrdup(*argv); |
Denis Vlasenko | 818322b | 2007-09-24 18:27:04 +0000 | [diff] [blame] | 113 | src = concat_path_file(src, bb_get_last_path_component_strip(src_name)); |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 114 | free(src_name); |
Glenn L McGrath | cfc0ad4 | 2003-12-31 23:10:44 +0000 | [diff] [blame] | 115 | src_name = src; |
| 116 | } |
Denys Vlasenko | e992bae | 2009-11-28 15:18:53 +0100 | [diff] [blame] | 117 | if (!(opts & LN_SYMLINK) && stat(*argv, &statbuf)) { |
Denis Vlasenko | f24e1f4 | 2006-10-21 23:40:20 +0000 | [diff] [blame] | 118 | // coreutils: "ln dangling_symlink new_hardlink" works |
| 119 | if (lstat(*argv, &statbuf) || !S_ISLNK(statbuf.st_mode)) { |
Denis Vlasenko | 0c97c9d | 2007-10-01 11:58:38 +0000 | [diff] [blame] | 120 | bb_simple_perror_msg(*argv); |
Denis Vlasenko | f24e1f4 | 2006-10-21 23:40:20 +0000 | [diff] [blame] | 121 | status = EXIT_FAILURE; |
| 122 | free(src_name); |
| 123 | continue; |
| 124 | } |
Eric Andersen | 815e904 | 2000-06-06 16:15:23 +0000 | [diff] [blame] | 125 | } |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 126 | |
Denys Vlasenko | e992bae | 2009-11-28 15:18:53 +0100 | [diff] [blame] | 127 | if (opts & LN_BACKUP) { |
Denis Vlasenko | f24e1f4 | 2006-10-21 23:40:20 +0000 | [diff] [blame] | 128 | char *backup; |
| 129 | backup = xasprintf("%s%s", src, suffix); |
| 130 | if (rename(src, backup) < 0 && errno != ENOENT) { |
Denis Vlasenko | 0c97c9d | 2007-10-01 11:58:38 +0000 | [diff] [blame] | 131 | bb_simple_perror_msg(src); |
Denis Vlasenko | f24e1f4 | 2006-10-21 23:40:20 +0000 | [diff] [blame] | 132 | status = EXIT_FAILURE; |
Rob Landley | 3071e2f | 2005-04-29 22:13:04 +0000 | [diff] [blame] | 133 | free(backup); |
Denis Vlasenko | f24e1f4 | 2006-10-21 23:40:20 +0000 | [diff] [blame] | 134 | continue; |
| 135 | } |
| 136 | free(backup); |
| 137 | /* |
| 138 | * When the source and dest are both hard links to the same |
| 139 | * inode, a rename may succeed even though nothing happened. |
| 140 | * Therefore, always unlink(). |
| 141 | */ |
| 142 | unlink(src); |
Denys Vlasenko | e992bae | 2009-11-28 15:18:53 +0100 | [diff] [blame] | 143 | } else if (opts & LN_FORCE) { |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 144 | unlink(src); |
| 145 | } |
| 146 | |
| 147 | link_func = link; |
Denys Vlasenko | e992bae | 2009-11-28 15:18:53 +0100 | [diff] [blame] | 148 | if (opts & LN_SYMLINK) { |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 149 | link_func = symlink; |
| 150 | } |
Eric Andersen | c7bda1c | 2004-03-15 08:29:22 +0000 | [diff] [blame] | 151 | |
Simon B | 44642d1 | 2012-05-06 13:18:35 +0200 | [diff] [blame] | 152 | if (opts & LN_VERBOSE) { |
| 153 | printf("'%s' -> '%s'\n", src, *argv); |
| 154 | } |
| 155 | |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 156 | if (link_func(*argv, src) != 0) { |
Denis Vlasenko | 0c97c9d | 2007-10-01 11:58:38 +0000 | [diff] [blame] | 157 | bb_simple_perror_msg(src); |
Glenn L McGrath | cfc0ad4 | 2003-12-31 23:10:44 +0000 | [diff] [blame] | 158 | status = EXIT_FAILURE; |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 159 | } |
| 160 | |
| 161 | free(src_name); |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 162 | } while ((++argv)[1]); |
| 163 | |
Eric Andersen | fcffa2c | 2002-04-06 05:17:57 +0000 | [diff] [blame] | 164 | return status; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 165 | } |