readlink.c (2096B)
1 // $Id$ 2 3 // Copyright (C) 2003 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de> 4 // 5 // This program is free software; you can redistribute it and/or modify 6 // it under the terms of the GNU General Public License as published by 7 // the Free Software Foundation; either version 2, or (at your option) 8 // any later version. 9 // 10 // This program is distributed in the hope that it will be useful, 11 // but WITHOUT ANY WARRANTY; without even the implied warranty of 12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 // GNU General Public License for more details. 14 // 15 // You should have received a copy of the GNU General Public License 16 // along with this program; if not, write to the Free Software 17 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 18 19 #ifdef HAVE_CONFIG_H 20 # include <config.h> 21 #endif 22 23 #include "util.h" 24 25 #include <string.h> 26 #include <errno.h> 27 #include <limits.h> 28 #include <unistd.h> 29 #include <stdio.h> 30 31 static void 32 showHelp(char const *cmd) 33 { 34 WRITE_MSG(1, "Usage: "); 35 WRITE_STR(1, cmd); 36 WRITE_MSG(1, 37 " [--] <filename>\n" 38 "\n" 39 "Display value of a symbolic link on standard output.\n" 40 "\n" 41 "Please report bugs to " PACKAGE_BUGREPORT "\n"); 42 exit(0); 43 } 44 45 static void 46 showVersion() 47 { 48 WRITE_MSG(1, 49 "readlink " VERSION " -- display value of symlink\n" 50 "This program is part of " PACKAGE_STRING "\n\n" 51 "Copyright (C) 2004 Enrico Scholz\n" 52 VERSION_COPYRIGHT_DISCLAIMER); 53 exit(0); 54 } 55 56 57 int main (int argc, char *argv[]) 58 { 59 char buf[PATH_MAX + 2]; 60 int idx = 1; 61 int len; 62 63 if (argc>=2) { 64 if (strcmp(argv[1], "--help") ==0) showHelp(argv[0]); 65 if (strcmp(argv[1], "--version")==0) showVersion(); 66 if (strcmp(argv[1], "--") ==0) ++idx; 67 } 68 if (argc<idx+1) 69 WRITE_MSG(2, "No filename specified; use '--help' for more information\n"); 70 else if ((len=readlink(argv[idx], buf, sizeof(buf)-2))==-1) 71 PERROR_Q("readlink: readlink", argv[idx]); 72 else { 73 buf[len++] = '\n'; 74 Vwrite(1, buf, len); 75 return EXIT_SUCCESS; 76 } 77 78 return EXIT_FAILURE; 79 } 80