src/filename_absolute.cxx

   1 //
   2 // "$Id: filename_absolute.cxx 8146 2010-12-31 22:13:07Z matt $"
   3 //
   4 // Filename expansion routines for the Fast Light Tool Kit (FLTK).
   5 //
   6 // Copyright 1998-2010 by Bill Spitzak and others.
   7 //
   8 // This library is free software; you can redistribute it and/or
   9 // modify it under the terms of the GNU Library General Public
  10 // License as published by the Free Software Foundation; either
  11 // version 2 of the License, or (at your option) any later version.
  12 //
  13 // This library 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 // Library General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU Library General Public
  19 // License along with this library; if not, write to the Free Software
  20 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  21 // USA.
  22 //
  23 // Please report all bugs and problems on the following page:
  24 //
  25 //     http://www.fltk.org/str.php
  26 //
  27
  28 /* expand a file name by prepending current directory, deleting . and
  29    .. (not really correct for symbolic links) between the prepended
  30    current directory.  Use $PWD if it exists.
  31    Returns true if any changes were made.
  32 */
  33
  34 #include <FL/filename.H>
  35 #include <FL/fl_utf8.h>
  36 #include <stdlib.h>
  37 #include "flstring.h"
  38 #include <ctype.h>
  39 #if defined(WIN32) && !defined(__CYGWIN__)
  40 # include <direct.h>
  41 #else
  42 #  include <unistd.h>
  43 #endif
  44
  45 #if defined(WIN32) || defined(__EMX__) && !defined(__CYGWIN__)
  46 inline int isdirsep(char c) {return c=='/' || c=='\\';}
  47 #else
  48 #define isdirsep(c) ((c)=='/')
  49 #endif
  50
  51 /** Makes a filename absolute from a relative filename.
  52     \code
  53     #include <FL/filename.H>
  54     [..]
  55     chdir("/var/tmp");
  56     fl_filename_absolute(out, sizeof(out), "foo.txt");         // out="/var/tmp/foo.txt"
  57     fl_filename_absolute(out, sizeof(out), "./foo.txt");       // out="/var/tmp/foo.txt"
  58     fl_filename_absolute(out, sizeof(out), "../log/messages"); // out="/var/log/messages"
  59     \endcode
  60     \param[out] to resulting absolute filename
  61     \param[in]  tolen size of the absolute filename buffer
  62     \param[in]  from relative filename
  63     \return 0 if no change, non zero otherwise
  64  */
  65 int fl_filename_absolute(char *to, int tolen, const char *from) {
  66   if (isdirsep(*from) || *from == '|'
  67 #if defined(WIN32) || defined(__EMX__) && !defined(__CYGWIN__)
  68       || from[1]==':'
  69 #endif
  70       ) {
  71     strlcpy(to, from, tolen);
  72     return 0;
  73   }
  74
  75   char *a;
  76   char *temp = new char[tolen];
  77   const char *start = from;
  78
  79   a = fl_getcwd(temp, tolen);
  80   if (!a) {
  81     strlcpy(to, from, tolen);
  82     delete[] temp;
  83     return 0;
  84   }
  85 #if defined(WIN32) || defined(__EMX__) && !defined(__CYGWIN__)
  86   for (a = temp; *a; a++) if (*a=='\\') *a = '/'; // ha ha
  87 #else
  88   a = temp+strlen(temp);
  89 #endif
  90   if (isdirsep(*(a-1))) a--;
  91   /* remove intermediate . and .. names: */
  92   while (*start == '.') {
  93     if (start[1]=='.' && isdirsep(start[2])) {
  94       char *b;
  95       for (b = a-1; b >= temp && !isdirsep(*b); b--);
  96       if (b < temp) break;
  97       a = b;
  98       start += 3;
  99     } else if (isdirsep(start[1])) {
 100       start += 2;
 101     } else if (!start[1]) {
 102       start ++; // Skip lone "."
 103       break;
 104     } else
 105       break;
 106   }
 107
 108   *a++ = '/';
 109   strlcpy(a,start,tolen - (a - temp));
 110
 111   strlcpy(to, temp, tolen);
 112
 113   delete[] temp;
 114
 115   return 1;
 116 }
 117
 118 /** Makes a filename relative to the current working directory.
 119     \code
 120     #include <FL/filename.H>
 121     [..]
 122     chdir("/var/tmp/somedir");       // set cwd to /var/tmp/somedir
 123     [..]
 124     char out[FL_PATH_MAX];
 125     fl_filename_relative(out, sizeof(out), "/var/tmp/somedir/foo.txt");  // out="foo.txt",    return=1
 126     fl_filename_relative(out, sizeof(out), "/var/tmp/foo.txt");          // out="../foo.txt", return=1
 127     fl_filename_relative(out, sizeof(out), "foo.txt");                   // out="foo.txt",    return=0 (no change)
 128     fl_filename_relative(out, sizeof(out), "./foo.txt");                 // out="./foo.txt",  return=0 (no change)
 129     fl_filename_relative(out, sizeof(out), "../foo.txt");                // out="../foo.txt", return=0 (no change)
 130     \endcode
 131     \param[out] to resulting relative filename
 132     \param[in]  tolen size of the relative filename buffer
 133     \param[in]  from absolute filename
 134     \return 0 if no change, non zero otherwise
 135  */
 136 int                                     // O - 0 if no change, 1 if changed
 137 fl_filename_relative(char       *to,    // O - Relative filename
 138                      int        tolen,  // I - Size of "to" buffer
 139                      const char *from)  // I - Absolute filename
 140 {
 141   char cwd_buf[FL_PATH_MAX];    // Current directory
 142   // get the current directory and return if we can't
 143   if (!fl_getcwd(cwd_buf, sizeof(cwd_buf))) {
 144     strlcpy(to, from, tolen);
 145     return 0;
 146   }
 147   return fl_filename_relative(to, tolen, from, cwd_buf);
 148 }
 149
 150
 151 /** Makes a filename relative to any other directory.
 152  \param[out] to resulting relative filename
 153  \param[in]  tolen size of the relative filename buffer
 154  \param[in]  from absolute filename
 155  \param[in]  base relative to this absolute path
 156  \return 0 if no change, non zero otherwise
 157  */
 158 int                                     // O - 0 if no change, 1 if changed
 159 fl_filename_relative(char       *to,    // O - Relative filename
 160                      int        tolen,  // I - Size of "to" buffer
 161                      const char *from,  // I - Absolute filename
 162                      const char *base) { // I - Find path relative to this path
 163
 164   char          *newslash;              // Directory separator
 165   const char    *slash;                 // Directory separator
 166   char          *cwd = 0L, *cwd_buf = 0L;
 167   if (base) cwd = cwd_buf = strdup(base);
 168
 169   // return if "from" is not an absolute path
 170 #if defined(WIN32) || defined(__EMX__)
 171   if (from[0] == '\0' ||
 172       (!isdirsep(*from) && !isalpha(*from) && from[1] != ':' &&
 173        !isdirsep(from[2]))) {
 174 #else
 175   if (from[0] == '\0' || !isdirsep(*from)) {
 176 #endif // WIN32 || __EMX__
 177     strlcpy(to, from, tolen);
 178     if (cwd_buf) free(cwd_buf);
 179     return 0;
 180   }
 181
 182   // return if "cwd" is not an absolute path
 183 #if defined(WIN32) || defined(__EMX__)
 184   if (!cwd || cwd[0] == '\0' ||
 185       (!isdirsep(*cwd) && !isalpha(*cwd) && cwd[1] != ':' &&
 186        !isdirsep(cwd[2]))) {
 187 #else
 188   if (!cwd || cwd[0] == '\0' || !isdirsep(*cwd)) {
 189 #endif // WIN32 || __EMX__
 190     strlcpy(to, from, tolen);
 191     if (cwd_buf) free(cwd_buf);
 192     return 0;
 193   }
 194
 195 #if defined(WIN32) || defined(__EMX__)
 196   // convert all backslashes into forward slashes
 197   for (newslash = strchr(cwd, '\\'); newslash; newslash = strchr(newslash + 1, '\\'))
 198     *newslash = '/';
 199
 200   // test for the exact same string and return "." if so
 201   if (!strcasecmp(from, cwd)) {
 202     strlcpy(to, ".", tolen);
 203     free(cwd_buf);
 204     return (1);
 205   }
 206
 207   // test for the same drive. Return the absolute path if not
 208   if (tolower(*from & 255) != tolower(*cwd & 255)) {
 209     // Not the same drive...
 210     strlcpy(to, from, tolen);
 211     free(cwd_buf);
 212     return 0;
 213   }
 214
 215   // compare the path name without the drive prefix
 216   from += 2; cwd += 2;
 217 #else
 218   // test for the exact same string and return "." if so
 219   if (!strcmp(from, cwd)) {
 220     strlcpy(to, ".", tolen);
 221     free(cwd_buf);
 222     return (1);
 223   }
 224 #endif // WIN32 || __EMX__
 225
 226   // compare both path names until we find a difference
 227   for (slash = from, newslash = cwd;
 228       *slash != '\0' && *newslash != '\0';
 229        slash ++, newslash ++)
 230     if (isdirsep(*slash) && isdirsep(*newslash)) continue;
 231 #if defined(WIN32) || defined(__EMX__) || defined(__APPLE__)
 232     else if (tolower(*slash & 255) != tolower(*newslash & 255)) break;
 233 #else
 234     else if (*slash != *newslash) break;
 235 #endif // WIN32 || __EMX__ || __APPLE__
 236
 237   // skip over trailing slashes
 238   if ( *newslash == '\0' && *slash != '\0' && !isdirsep(*slash)
 239      &&(newslash==cwd || !isdirsep(newslash[-1])) )
 240     newslash--;
 241
 242   // now go back to the first character of the first differing paths segment
 243   while (!isdirsep(*slash) && slash > from) slash --;
 244   if (isdirsep(*slash)) slash ++;
 245
 246   // do the same for the current dir
 247   if (isdirsep(*newslash)) newslash --;
 248   if (*newslash != '\0')
 249     while (!isdirsep(*newslash) && newslash > cwd) newslash --;
 250
 251   // prepare the destination buffer
 252   to[0]         = '\0';
 253   to[tolen - 1] = '\0';
 254
 255   // now add a "previous dir" sequence for every following slash in the cwd
 256   while (*newslash != '\0') {
 257     if (isdirsep(*newslash)) strlcat(to, "../", tolen);
 258
 259     newslash ++;
 260   }
 261
 262   // finally add the differing path from "from"
 263   strlcat(to, slash, tolen);
 264
 265   free(cwd_buf);
 266   return 1;
 267 }
 268
 269
 270 //
 271 // End of "$Id: filename_absolute.cxx 8146 2010-12-31 22:13:07Z matt $".
 272 //