src/libs/libgroff/relocate.cpp

   1 // -*- C++ -*-
   2 /* Provide relocation for macro and font files.
   3    Copyright (C) 2005 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify it
   6    under the terms of the GNU Library General Public License as published
   7    by 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 GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with this program; if not, write to the Free Software
  17    Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301,
  18    USA.  */
  19
  20 // Made after relocation code in kpathsea and gettext.
  21
  22 #include "lib.h"
  23
  24 #include <errno.h>
  25 #include <stdlib.h>
  26
  27 #include "defs.h"
  28 #include "posix.h"
  29 #include "nonposix.h"
  30 #include "relocate.h"
  31
  32 #if defined _WIN32
  33 # define WIN32_LEAN_AND_MEAN
  34 # include <windows.h>
  35 #endif
  36
  37 #define INSTALLPATHLEN (sizeof(INSTALLPATH) - 1)
  38 #ifndef DEBUG
  39 # define DEBUG 0
  40 #endif
  41
  42 extern "C" const char *program_name;
  43
  44 // The prefix (parent directory) corresponding to the binary.
  45 char *curr_prefix = 0;
  46 size_t curr_prefix_len = 0;
  47
  48 // Return the directory part of a filename, or `.' if no path separators.
  49 char *xdirname(char *s)
  50 {
  51   static const char dot[] = ".";
  52   if (!s)
  53     return 0;
  54   // DIR_SEPS[] are possible directory separator characters, see nonposix.h.
  55   // We want the rightmost separator of all possible ones.
  56   // Example: d:/foo\\bar.
  57   char *p = strrchr(s, DIR_SEPS[0]);
  58   const char *sep = &DIR_SEPS[1];
  59   while (*sep) {
  60     char *p1 = strrchr(s, *sep);
  61     if (p1 && (!p || p1 > p))
  62       p = p1;
  63     sep++;
  64   }
  65   if (p)
  66     *p = '\0';
  67   else
  68     s = (char *)dot;
  69   return s;
  70 }
  71
  72 // Return the full path of NAME along the path PATHP.
  73 // Adapted from search_path::open_file in searchpath.cpp.
  74 char *searchpath(const char *name, const char *pathp)
  75 {
  76   char *path;
  77   if (!name || !*name)
  78     return 0;
  79 #if DEBUG
  80   fprintf(stderr, "searchpath: pathp: `%s'\n", pathp);
  81   fprintf(stderr, "searchpath: trying `%s'\n", name);
  82 #endif
  83   // Try first NAME as such; success if NAME is an absolute filename,
  84   // or if NAME is found in the current directory.
  85   if (!access (name, F_OK)) {
  86     path = new char[path_name_max()];
  87 #ifdef _WIN32
  88     path = _fullpath(path, name, path_name_max());
  89 #else
  90     path = realpath(name, path);
  91 #endif
  92 #if DEBUG
  93     fprintf(stderr, "searchpath: found `%s'\n", path);
  94 #endif
  95     return path;
  96   }
  97   // Secondly, try the current directory.
  98   // Now search along PATHP.
  99   size_t namelen = strlen(name);
 100   char *p = (char *)pathp;
 101   for (;;) {
 102     char *end = strchr(p, PATH_SEP_CHAR);
 103     if (!end)
 104       end = strchr(p, '\0');
 105     int need_slash = end > p && strchr(DIR_SEPS, end[-1]) == 0;
 106     path = new char[end - p + need_slash + namelen + 1];
 107     memcpy(path, p, end - p);
 108     if (need_slash)
 109       path[end - p] = '/';
 110     strcpy(path + (end - p) + need_slash, name);
 111 #if DEBUG
 112     fprintf(stderr, "searchpath: trying `%s'\n", path);
 113 #endif
 114     if (!access(path, F_OK)) {
 115 #if DEBUG
 116       fprintf(stderr, "searchpath: found `%s'\n", name);
 117 #endif
 118       return path;
 119     }
 120     a_delete path;
 121     if (*end == '\0')
 122       break;
 123     p = end + 1;
 124   }
 125   return 0;
 126 }
 127
 128 // Search NAME along PATHP with the elements of PATHEXT in turn added.
 129 char *searchpathext(const char *name, const char *pathext, const char *pathp)
 130 {
 131   char *found = 0;
 132   char *tmpathext = strsave(pathext);   // strtok modifies this string,
 133                                         // so make a copy
 134   char *ext = strtok(tmpathext, PATH_SEP);
 135   while (ext) {
 136     char *namex = new char[strlen(name) + strlen(ext) + 1];
 137     strcpy(namex, name);
 138     strcat(namex, ext);
 139     found = searchpath(namex, pathp);
 140     a_delete namex;
 141     if (found)
 142        break;
 143     ext = strtok(0, PATH_SEP);
 144   }
 145   a_delete tmpathext;
 146   return found;
 147 }
 148
 149 // Convert an MS path to a POSIX path.
 150 char *msw2posixpath(char *path)
 151 {
 152   char *s = path;
 153   while (*s) {
 154     if (*s == '\\')
 155       *s = '/';
 156     *s++;
 157   }
 158   return path;
 159 }
 160
 161 // Compute the current prefix.
 162 void set_current_prefix()
 163 {
 164   char *pathextstr;
 165   curr_prefix = new char[path_name_max()];
 166   // Obtain the full path of the current binary;
 167   // using GetModuleFileName on MS-Windows,
 168   // and searching along PATH on other systems.
 169 #ifdef _WIN32
 170   int len = GetModuleFileName(0, curr_prefix, path_name_max());
 171   if (len)
 172     len = GetShortPathName(curr_prefix, curr_prefix, path_name_max());
 173 # if DEBUG
 174   fprintf(stderr, "curr_prefix: %s\n", curr_prefix);
 175 # endif /* DEBUG */
 176 #else /* !_WIN32 */
 177   curr_prefix = searchpath(program_name, getenv("PATH"));
 178   if (!curr_prefix && !strchr(program_name, '.')) {     // try with extensions
 179     pathextstr = strsave(getenv("PATHEXT"));
 180     if (!pathextstr)
 181       pathextstr = strsave(PATH_EXT);
 182     curr_prefix = searchpathext(program_name, pathextstr, getenv("PATH"));
 183     a_delete pathextstr;
 184   }
 185   if (!curr_prefix)
 186     return;
 187 #endif /* !_WIN32 */
 188   msw2posixpath(curr_prefix);
 189 #if DEBUG
 190   fprintf(stderr, "curr_prefix: %s\n", curr_prefix);
 191 #endif
 192   curr_prefix = xdirname(curr_prefix);  // directory of executable
 193   curr_prefix = xdirname(curr_prefix);  // parent directory of executable
 194   curr_prefix_len = strlen(curr_prefix);
 195 #if DEBUG
 196   fprintf(stderr, "curr_prefix: %s\n", curr_prefix);
 197   fprintf(stderr, "curr_prefix_len: %d\n", curr_prefix_len);
 198 #endif
 199 }
 200
 201 // Strip the installation prefix and replace it
 202 // with the current installation prefix; return the relocated path.
 203 char *relocatep(const char *path)
 204 {
 205 #if DEBUG
 206   fprintf(stderr, "relocatep: path = %s\n", path);
 207   fprintf(stderr, "relocatep: INSTALLPATH = %s\n", INSTALLPATH);
 208   fprintf(stderr, "relocatep: INSTALLPATHLEN = %d\n", INSTALLPATHLEN);
 209 #endif
 210   if (!curr_prefix)
 211     set_current_prefix();
 212   if (strncmp(INSTALLPATH, path, INSTALLPATHLEN))
 213     return strsave(path);
 214   char *relative_path = (char *)path + INSTALLPATHLEN;
 215   size_t relative_path_len = strlen(relative_path);
 216   char *relocated_path = new char[curr_prefix_len + relative_path_len + 1];
 217   strcpy(relocated_path, curr_prefix);
 218   strcat(relocated_path, relative_path);
 219 #if DEBUG
 220   fprintf(stderr, "relocated_path: %s\n", relocated_path);
 221 #endif /* DEBUG */
 222   return relocated_path;
 223 }
 224
 225 // Return the original pathname if it exists;
 226 // otherwise return the relocated path.
 227 char *relocate(const char *path)
 228 {
 229   char *p;
 230   if (access(path, F_OK))
 231     p = relocatep(path);
 232   else
 233     p = strsave(path);
 234 #if DEBUG
 235   fprintf (stderr, "relocate: %s\n", p);
 236 #endif
 237   return p;
 238 }