filename_expand.cxx

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//
// "$Id$"
//
// Filename expansion routines for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2010 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
//     http://www.fltk.org/str.php
//
 
/* expand a file name by substuting environment variables and
   home directories.  Returns true if any changes were made.
   to & from may be the same buffer.
*/
 
#include <FL/filename.H>
#include <FL/fl_utf8.h>
#include <stdlib.h>
#include "flstring.h"
#if defined(WIN32) && !defined(__CYGWIN__)
#include <windows.h>
#else
# include <unistd.h>
# include <pwd.h>
#endif
 
#if defined(WIN32) || defined(__EMX__) && !defined(__CYGWIN__)
static inline int isdirsep(char c) {return c=='/' || c=='\\';}
#else
#define isdirsep(c) ((c)=='/')
#endif
 
int fl_filename_expand(char *to,int tolen, const char *from) {
 
  char *temp = new char[tolen];
  strlcpy(temp,from, tolen);
  char *start = temp;
  char *end = temp+strlen(temp);
 
  int ret = 0;
 
  for (char *a=temp; a<end; ) { // for each slash component
    char *e; for (e=a; e<end && !isdirsep(*e); e++) {/*empty*/} // find next slash
    const char *value = 0; // this will point at substitute value
    switch (*a) {
    case '~':   // a home directory name
      if (e <= a+1) {   // current user's directory
        value = fl_getenv("HOME");
#ifndef WIN32
      } else {  // another user's directory
    struct passwd *pwd;
    char t = *e; *(char *)e = 0; 
        pwd = getpwnam(a+1); 
        *(char *)e = t;
        if (pwd) value = pwd->pw_dir;
#endif
      }
      break;
    case '$':       /* an environment variable */
      {char t = *e; *(char *)e = 0; value = fl_getenv(a+1); *(char *)e = t;}
      break;
    }
    if (value) {
      // substitutions that start with slash delete everything before them:
      if (isdirsep(value[0])) start = a;
#if defined(WIN32) || defined(__EMX__) && !defined(__CYGWIN__)
      // also if it starts with "A:"
      if (value[0] && value[1]==':') start = a;
#endif
      int t = (int) strlen(value); if (isdirsep(value[t-1])) t--;
      if ((end+1-e+t) >= tolen) end += tolen - (end+1-e+t);
      memmove(a+t, e, end+1-e);
      end = a+t+(end-e);
      *end = '\0';
      memcpy(a, value, t);
      ret++;
    } else {
      a = e+1;
#if defined(WIN32) || defined(__EMX__) && !defined(__CYGWIN__)
      if (*e == '\\') {*e = '/'; ret++;} // ha ha!
#endif
    }
  }
 
  strlcpy(to, start, tolen);
 
  delete[] temp;
 
  return ret;
}
 
 
//
// End of "$Id$".
//