usr/src/lib/libast/common/path/pathprog.c

   1 /***********************************************************************
   2 *                                                                      *
   3 *               This software is part of the ast package               *
   4 *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
   5 *                      and is licensed under the                       *
   6 *                  Common Public License, Version 1.0                  *
   7 *                    by AT&T Intellectual Property                     *
   8 *                                                                      *
   9 *                A copy of the License is available at                 *
  10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
  11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
  12 *                                                                      *
  13 *              Information and Software Systems Research               *
  14 *                            AT&T Research                             *
  15 *                           Florham Park NJ                            *
  16 *                                                                      *
  17 *                 Glenn Fowler <gsf@research.att.com>                  *
  18 *                  David Korn <dgk@research.att.com>                   *
  19 *                   Phong Vo <kpv@research.att.com>                    *
  20 *                                                                      *
  21 ***********************************************************************/
  22 #pragma prototyped
  23 /*
  24  * Glenn Fowler
  25  * AT&T Research
  26  *
  27  * return the full path of the current program in path
  28  * command!=0 is used as a default
  29  */
  30
  31 #include <ast.h>
  32
  33 #if _WINIX
  34 #include <ast_windows.h>
  35 #include <ctype.h>
  36 #endif
  37
  38 #include "FEATURE/prog"
  39
  40 static size_t
  41 prog(const char* command, char* path, size_t size)
  42 {
  43         ssize_t         n;
  44 #if _WINIX || _lib_getexecname
  45         char*           s;
  46 #endif
  47 #if _WINIX
  48         char*           t;
  49         char*           e;
  50         int             c;
  51         int             q;
  52 #endif
  53
  54 #ifdef _PROC_PROG
  55         if ((n = readlink(_PROC_PROG, path, size)) > 0)
  56         {
  57                 if (n < size)
  58                         path[n] = 0;
  59                 return n;
  60         }
  61 #endif
  62 #if _lib_getexecname
  63         if (s = (char*)getexecname())
  64         {
  65                 n = strlen(s);
  66                 if (n < size)
  67                         strcpy(path, s);
  68                 return n;
  69         }
  70 #endif
  71 #if _WINIX
  72         if (s = GetCommandLine())
  73         {
  74                 n = 0;
  75                 q = 0;
  76                 t = path;
  77                 e = path + size - 1;
  78                 while (c = *s++)
  79                 {
  80                         if (c == q)
  81                                 q = 0;
  82                         else if (!q && c == '"')
  83                                 q = c;
  84                         else if (!q && isspace(c))
  85                                 break;
  86                         else if (t < e)
  87                                 *t++ = c == '\\' ? '/' : c;
  88                         else
  89                                 n++;
  90                 }
  91                 if (t < e)
  92                         *t = 0;
  93                 return (t - path) + n;
  94         }
  95 #endif
  96         if (command)
  97         {
  98                 if ((n = strlen(command) + 1) <= size)
  99                         memcpy(path, command, n);
 100                 return n;
 101         }
 102         return 0;
 103 }
 104
 105 size_t
 106 pathprog(const char* command, char* path, size_t size)
 107 {
 108         ssize_t         n;
 109         char            buf[PATH_MAX];
 110
 111         if ((n = prog(command, path, size)) > 0 && n <= size && *path != '/')
 112         {
 113                 if (!pathpath(buf, path, NiL, PATH_REGULAR|PATH_EXECUTE))
 114                         n = 0;
 115                 else if ((n = strlen(buf) + 1) <= size)
 116                         memcpy(path, buf, n);
 117         }
 118         return n;
 119 }