/* vi: set sw=4 ts=4: */ /* * Mini ln implementation for busybox * * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> * * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ /* BB_AUDIT SUSv3 compliant */ /* BB_AUDIT GNU options missing: -d, -F, -i, and -v. */ /* http://www.opengroup.org/onlinepubs/007904975/utilities/ln.html */ //usage:#define ln_trivial_usage //usage: "[OPTIONS] TARGET... LINK|DIR" //usage:#define ln_full_usage "\n\n" //usage: "Create a link LINK or DIR/TARGET to the specified TARGET(s)\n" //usage: "\n -s Make symlinks instead of hardlinks" //usage: "\n -f Remove existing destinations" //usage: "\n -n Don't dereference symlinks - treat like normal file" //usage: "\n -b Make a backup of the target (if exists) before link operation" //usage: "\n -S suf Use suffix instead of ~ when making backup files" //usage: "\n -T 2nd arg must be a DIR" //usage: "\n -v Verbose" //usage: //usage:#define ln_example_usage //usage: "$ ln -s BusyBox /tmp/ls\n" //usage: "$ ls -l /tmp/ls\n" //usage: "lrwxrwxrwx 1 root root 7 Apr 12 18:39 ls -> BusyBox*\n" #include "libbb.h" /* This is a NOEXEC applet. Be very careful! */ #define LN_SYMLINK (1 << 0) #define LN_FORCE (1 << 1) #define LN_NODEREFERENCE (1 << 2) #define LN_BACKUP (1 << 3) #define LN_SUFFIX (1 << 4) #define LN_VERBOSE (1 << 5) #define LN_LINKFILE (1 << 6) int ln_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int ln_main(int argc, char **argv) { int status = EXIT_SUCCESS; int opts; char *last; char *src_name; char *src; char *suffix = (char*)"~"; struct stat statbuf; int (*link_func)(const char *, const char *); opt_complementary = "-1"; /* min one arg */ opts = getopt32(argv, "sfnbS:vT", &suffix); last = argv[argc - 1]; argv += optind; argc -= optind; if ((opts & LN_LINKFILE) && argc > 2) { bb_error_msg_and_die("-T accepts 2 args max"); } if (!argv[1]) { /* "ln PATH/TO/FILE" -> "ln PATH/TO/FILE FILE" */ *--argv = last; /* xstrdup is needed: "ln -s PATH/TO/FILE/" is equivalent to * "ln -s PATH/TO/FILE/ FILE", not "ln -s PATH/TO/FILE FILE" */ last = bb_get_last_path_component_strip(xstrdup(last)); } do { src_name = NULL; src = last; if (is_directory(src, (opts & LN_NODEREFERENCE) ^ LN_NODEREFERENCE ) ) { if (opts & LN_LINKFILE) { bb_error_msg_and_die("'%s' is a directory", src); } src_name = xstrdup(*argv); src = concat_path_file(src, bb_get_last_path_component_strip(src_name)); free(src_name); src_name = src; } if (!(opts & LN_SYMLINK) && stat(*argv, &statbuf)) { // coreutils: "ln dangling_symlink new_hardlink" works if (lstat(*argv, &statbuf) || !S_ISLNK(statbuf.st_mode)) { bb_simple_perror_msg(*argv); status = EXIT_FAILURE; free(src_name); continue; } } if (opts & LN_BACKUP) { char *backup; backup = xasprintf("%s%s", src, suffix); if (rename(src, backup) < 0 && errno != ENOENT) { bb_simple_perror_msg(src); status = EXIT_FAILURE; free(backup); continue; } free(backup); /* * When the source and dest are both hard links to the same * inode, a rename may succeed even though nothing happened. * Therefore, always unlink(). */ unlink(src); } else if (opts & LN_FORCE) { unlink(src); } link_func = link; if (opts & LN_SYMLINK) { link_func = symlink; } if (opts & LN_VERBOSE) { printf("'%s' -> '%s'\n", src, *argv); } if (link_func(*argv, src) != 0) { bb_simple_perror_msg(src); status = EXIT_FAILURE; } free(src_name); } while ((++argv)[1]); return status; }