src/libs/libgroff/searchpath.cc

   1 // -*- C++ -*-
   2 /* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
   3      Written by James Clark (jjc@jclark.com)
   4
   5 This file is part of groff.
   6
   7 groff is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 groff is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License along
  18 with groff; see the file COPYING.  If not, write to the Free Software
  19 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
  20
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <stdlib.h>
  24 #include <assert.h>
  25
  26 #include "lib.h"
  27 #include "searchpath.h"
  28
  29 search_path::search_path(const char *envvar, const char *standard)
  30 {
  31   char *e = envvar ? getenv(envvar) : 0;
  32   if (e && standard) {
  33     dirs = new char[strlen(e) + strlen(standard) + 2];
  34     strcpy(dirs, e);
  35     strcat(dirs, ":");
  36     strcat(dirs, standard);
  37   }
  38   else
  39     dirs = strsave(e ? e : standard);
  40   init_len = dirs ? strlen(dirs) : 0;
  41 }
  42
  43 search_path::~search_path()
  44 {
  45   if (dirs)
  46     a_delete dirs;
  47 }
  48
  49 void search_path::command_line_dir(const char *s)
  50 {
  51   if (!dirs)
  52     dirs = strsave(s);
  53   else {
  54     char *old = dirs;
  55     unsigned old_len = strlen(old);
  56     unsigned slen = strlen(s);
  57     dirs = new char[old_len + 1 + slen + 1];
  58     memcpy(dirs, old, old_len - init_len);
  59     char *p = dirs;
  60     p += old_len - init_len;
  61     if (init_len == 0)
  62       *p++ = ':';
  63     memcpy(p, s, slen);
  64     p += slen;
  65     if (init_len > 0) {
  66       *p++ = ':';
  67       memcpy(p, old + old_len - init_len, init_len);
  68       p += init_len;
  69     }
  70     *p++ = '\0';
  71     a_delete old;
  72   }
  73 }
  74
  75 FILE *search_path::open_file(const char *name, char **pathp)
  76 {
  77   assert(name != 0);
  78   if (*name == '/' || dirs == 0 || *dirs == '\0') {
  79     FILE *fp = fopen(name, "r");
  80     if (fp) {
  81       if (pathp)
  82         *pathp = strsave(name);
  83       return fp;
  84     }
  85     else
  86       return 0;
  87   }
  88   unsigned namelen = strlen(name);
  89   char *p = dirs;
  90   for (;;) {
  91 #ifdef _MSC_VER
  92     char *end = strchr(p, ';');
  93 #else
  94     char *end = strchr(p, ':');
  95 #endif
  96     if (!end)
  97       end = strchr(p, '\0');
  98     int need_slash = end > p && end[-1] != '/';
  99     char *path = new char[(end - p) + need_slash + namelen + 1];
 100     memcpy(path, p, end - p);
 101     if (need_slash)
 102       path[end - p] = '/';
 103     strcpy(path + (end - p) + need_slash, name);
 104 #if 0
 105     fprintf(stderr, "trying `%s'\n", path);
 106 #endif
 107     FILE *fp = fopen(path, "r");
 108     if (fp) {
 109       if (pathp)
 110         *pathp = path;
 111       else
 112         a_delete path;
 113       return fp;
 114     }
 115     a_delete path;
 116     if (*end == '\0')
 117       break;
 118     p = end + 1;
 119   }
 120   return 0;
 121 }