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\n"
  38         "Options:\n"
  39         "\t-s\tmake symbolic links instead of hard links\n"
  40
  41         "\t-f\tremove existing destination files\n"
  42         "\t-n\tno dereference symlinks - treat like normal file\n"
  43 #endif
  44         ;
  45
  46 static int symlinkFlag = FALSE;
  47 static int removeoldFlag = FALSE;
  48 static int followLinks = TRUE;
  49
  50 extern int ln_main(int argc, char **argv)
  51 {
  52         char *linkName;
  53         int linkIntoDirFlag;
  54         int stopIt = FALSE;
  55
  56         argc--;
  57         argv++;
  58
  59         /* Parse any options */
  60         while (argc > 0 && stopIt == FALSE) {
  61                 if (**argv == '-') {
  62                         while (*++(*argv))
  63                                 switch (**argv) {
  64                                         case 's':
  65                                                 symlinkFlag = TRUE;
  66                                                 break;
  67                                         case 'f':
  68                                                 removeoldFlag = TRUE;
  69                                                 break;
  70                                         case 'n':
  71                                                 followLinks = FALSE;
  72                                                 break;
  73                                         case '-':
  74                                                 stopIt = TRUE;
  75                                                 break;
  76                                         default:
  77                                                 usage(ln_usage);
  78                                 }
  79                         argc--;
  80                         argv++;
  81                 }
  82                 else
  83                         break;
  84         }
  85
  86         if (argc < 2) {
  87                 usage(ln_usage);
  88         }
  89
  90         linkName = argv[argc - 1];
  91
  92         if (strlen(linkName) > BUFSIZ) {
  93                 fprintf(stderr, name_too_long, "ln");
  94                 exit FALSE;
  95         }
  96
  97         linkIntoDirFlag = isDirectory(linkName, TRUE, NULL);
  98
  99         if ((argc >= 3) && linkIntoDirFlag == FALSE) {
 100                 fprintf(stderr, not_a_directory, "ln", linkName);
 101                 exit FALSE;
 102         }
 103
 104         while (argc-- >= 2) {
 105                 char srcName[BUFSIZ + 1];
 106                 int nChars, status;
 107
 108                 if (strlen(*argv) > BUFSIZ) {
 109                         fprintf(stderr, name_too_long, "ln");
 110                         exit FALSE;
 111                 }
 112
 113                 if (followLinks == FALSE) {
 114                         strcpy(srcName, *argv);
 115                 } else {
 116                         /* Warning!  This can silently truncate if > BUFSIZ, but
 117                            I don't think that there can be one > BUFSIZ anyway. */
 118                         nChars = readlink(*argv, srcName, BUFSIZ);
 119                         srcName[nChars] = '\0';
 120                 }
 121
 122                 if (removeoldFlag == TRUE) {
 123                         status = (unlink(linkName) && errno != ENOENT);
 124                         if (status != 0) {
 125                                 perror(linkName);
 126                                 exit FALSE;
 127                         }
 128                 }
 129
 130                 if (symlinkFlag == TRUE)
 131                         status = symlink(*argv, linkName);
 132                 else
 133                         status = link(*argv, linkName);
 134                 if (status != 0) {
 135                         perror(linkName);
 136                         exit FALSE;
 137                 }
 138         }
 139         return( TRUE);
 140 }
 141
 142 /*
 143 Local Variables:
 144 c-file-style: "linux"
 145 c-basic-offset: 4
 146 tab-width: 4
 147 End:
 148 */