coreutils/ln.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini ln implementation for busybox
   4  *
   5  * Copyright (C) 1999,2000 by Lineo, inc.
   6  * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  21  *
  22  */
  23
  24 #include "internal.h"
  25 #define BB_DECLARE_EXTERN
  26 #define bb_need_name_too_long
  27 #define bb_need_not_a_directory
  28 #include "messages.c"
  29
  30 #include <stdio.h>
  31 #include <dirent.h>
  32 #include <errno.h>
  33
  34 static const char ln_usage[] =
  35         "ln [OPTION] TARGET... LINK_NAME|DIRECTORY\n"
  36 #ifndef BB_FEATURE_TRIVIAL_HELP
  37         "\nCreate a link named LINK_NAME or DIRECTORY to the specified TARGET\n"
  38         "\nYou may use '--' to indicate that all following arguments are non-options.\n\n"
  39         "Options:\n"
  40         "\t-s\tmake symbolic links instead of hard links\n"
  41
  42         "\t-f\tremove existing destination files\n"
  43         "\t-n\tno dereference symlinks - treat like normal file\n"
  44 #endif
  45         ;
  46
  47 static int symlinkFlag = FALSE;
  48 static int removeoldFlag = FALSE;
  49 static int followLinks = TRUE;
  50
  51 extern int ln_main(int argc, char **argv)
  52 {
  53         char *linkName;
  54         int linkIntoDirFlag;
  55         int stopIt = FALSE;
  56
  57         argc--;
  58         argv++;
  59
  60         /* Parse any options */
  61         while (argc > 0 && stopIt == FALSE) {
  62                 if (**argv == '-') {
  63                         while (*++(*argv))
  64                                 switch (**argv) {
  65                                         case 's':
  66                                                 symlinkFlag = TRUE;
  67                                                 break;
  68                                         case 'f':
  69                                                 removeoldFlag = TRUE;
  70                                                 break;
  71                                         case 'n':
  72                                                 followLinks = FALSE;
  73                                                 break;
  74                                         case '-':
  75                                                 stopIt = TRUE;
  76                                                 break;
  77                                         default:
  78                                                 usage(ln_usage);
  79                                 }
  80                         argc--;
  81                         argv++;
  82                 }
  83                 else
  84                         break;
  85         }
  86
  87         if (argc < 2) {
  88                 usage(ln_usage);
  89         }
  90
  91         linkName = argv[argc - 1];
  92
  93         if (strlen(linkName) > BUFSIZ) {
  94                 fprintf(stderr, name_too_long, "ln");
  95                 exit FALSE;
  96         }
  97
  98         linkIntoDirFlag = isDirectory(linkName, TRUE, NULL);
  99
 100         if ((argc >= 3) && linkIntoDirFlag == FALSE) {
 101                 fprintf(stderr, not_a_directory, "ln", linkName);
 102                 exit FALSE;
 103         }
 104
 105         while (argc-- >= 2) {
 106                 char srcName[BUFSIZ + 1];
 107                 int nChars, status;
 108
 109                 if (strlen(*argv) > BUFSIZ) {
 110                         fprintf(stderr, name_too_long, "ln");
 111                         exit FALSE;
 112                 }
 113
 114                 if (followLinks == FALSE) {
 115                         strcpy(srcName, *argv);
 116                 } else {
 117                         /* Warning!  This can silently truncate if > BUFSIZ, but
 118                            I don't think that there can be one > BUFSIZ anyway. */
 119                         nChars = readlink(*argv, srcName, BUFSIZ);
 120                         srcName[nChars] = '\0';
 121                 }
 122
 123                 if (removeoldFlag == TRUE) {
 124                         status = (unlink(linkName) && errno != ENOENT);
 125                         if (status != 0) {
 126                                 perror(linkName);
 127                                 exit FALSE;
 128                         }
 129                 }
 130
 131                 if (symlinkFlag == TRUE)
 132                         status = symlink(*argv, linkName);
 133                 else
 134                         status = link(*argv, linkName);
 135                 if (status != 0) {
 136                         perror(linkName);
 137                         exit FALSE;
 138                 }
 139         }
 140         return( TRUE);
 141 }
 142
 143 /*
 144 Local Variables:
 145 c-file-style: "linux"
 146 c-basic-offset: 4
 147 tab-width: 4
 148 End:
 149 */