lib/sh/makepath.c

   1 /* makepath.c - glue PATH and DIR together into a full pathname. */
   2
   3 /* Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Bash, the Bourne Again SHell.
   6
   7    Bash is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    Bash is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include <config.h>
  22
  23 #if defined (HAVE_UNISTD_H)
  24 #  ifdef _MINIX
  25 #    include <sys/types.h>
  26 #  endif
  27 #  include <unistd.h>
  28 #endif
  29
  30 #include <bashansi.h>
  31 #include "shell.h"
  32
  33 #include <tilde/tilde.h>
  34
  35 #ifndef NULL
  36 #  define NULL 0
  37 #endif
  38
  39 /* MAKE SURE THESE AGREE WITH ../../externs.h. */
  40
  41 #ifndef MP_DOTILDE
  42 #  define MP_DOTILDE    0x01
  43 #  define MP_DOCWD      0x02
  44 #  define MP_RMDOT      0x04
  45 #  define MP_IGNDOT     0x08
  46 #endif
  47
  48 extern char *get_working_directory __P((char *));
  49
  50 static char *nullpath = "";
  51
  52 /* Take PATH, an element from, e.g., $CDPATH, and DIR, a directory name,
  53    and paste them together into PATH/DIR.  Tilde expansion is performed on
  54    PATH if (flags & MP_DOTILDE) is non-zero.  If PATH is NULL or the empty
  55    string, it is converted to the current directory.  A full pathname is
  56    used if (flags & MP_DOCWD) is non-zero, otherwise `./' is used.  If
  57    (flags & MP_RMDOT) is non-zero, any `./' is removed from the beginning
  58    of DIR.  If (flags & MP_IGNDOT) is non-zero, a PATH that is "." or "./"
  59    is ignored. */
  60
  61 #define MAKEDOT() \
  62   do { \
  63     xpath = (char *)xmalloc (2); \
  64     xpath[0] = '.'; \
  65     xpath[1] = '\0'; \
  66     pathlen = 1; \
  67   } while (0)
  68
  69 char *
  70 sh_makepath (path, dir, flags)
  71      const char *path, *dir;
  72      int flags;
  73 {
  74   int dirlen, pathlen;
  75   char *ret, *xpath, *xdir, *r, *s;
  76
  77   if (path == 0 || *path == '\0')
  78     {
  79       if (flags & MP_DOCWD)
  80         {
  81           xpath = get_working_directory ("sh_makepath");
  82           if (xpath == 0)
  83             {
  84               ret = get_string_value ("PWD");
  85               if (ret)
  86                 xpath = savestring (ret);
  87             }
  88           if (xpath == 0)
  89             MAKEDOT();
  90           else
  91             pathlen = strlen (xpath);
  92         }
  93       else
  94         MAKEDOT();
  95     }
  96   else if ((flags & MP_IGNDOT) && path[0] == '.' && (path[1] == '\0' ||
  97                                                      (path[1] == '/' && path[2] == '\0')))
  98     {
  99       xpath = nullpath;
 100       pathlen = 0;
 101     }
 102   else
 103     {
 104       xpath = ((flags & MP_DOTILDE) && *path == '~') ? bash_tilde_expand (path, 0) : (char *)path;
 105       pathlen = strlen (xpath);
 106     }
 107
 108   xdir = (char *)dir;
 109   dirlen = strlen (xdir);
 110   if ((flags & MP_RMDOT) && dir[0] == '.' && dir[1] == '/')
 111     {
 112       xdir += 2;
 113       dirlen -= 2;
 114     }
 115
 116   r = ret = (char *)xmalloc (2 + dirlen + pathlen);
 117   s = xpath;
 118   while (*s)
 119     *r++ = *s++;
 120   if (s > xpath && s[-1] != '/')
 121     *r++ = '/';
 122   s = xdir;
 123   while (*r++ = *s++)
 124     ;
 125   if (xpath != path && xpath != nullpath)
 126     free (xpath);
 127   return (ret);
 128 }