lib/findprog.h

   1 /* Locating a program in PATH.
   2    Copyright (C) 2001-2003, 2009-2020 Free Software Foundation, Inc.
   3    Written by Bruno Haible <haible@clisp.cons.org>, 2001.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _FINDPROG_H
  19 #define _FINDPROG_H
  20
  21 #include <stdbool.h>
  22
  23 #ifdef __cplusplus
  24 extern "C" {
  25 #endif
  26
  27
  28 /* Looks up a program in the PATH.
  29    Attempts to determine the pathname that would be called by execlp/execvp
  30    of PROGNAME.  If successful, it returns a pathname containing a slash
  31    (either absolute or relative to the current directory).  Otherwise, it
  32    returns PROGNAME unmodified.
  33    Because of the latter case, callers should use execlp/execvp, not
  34    execl/execv on the returned pathname.
  35    The returned string is freshly malloc()ed if it is != PROGNAME.  */
  36 extern const char *find_in_path (const char *progname);
  37
  38 /* Looks up a program in the given PATH-like string.
  39
  40    The PATH argument consists of a list of directories, separated by ':' or
  41    (on native Windows) by ';'.  An empty PATH element designates the current
  42    directory.  A null PATH is equivalent to an empty PATH, that is, to the
  43    singleton list that contains only the current directory.
  44
  45    If DIRECTORY is not NULL, all relative filenames (i.e. PROGNAME when it
  46    contains a slash, and the PATH elements) are considered relative to
  47    DIRECTORY instead of relative to the current directory of this process.
  48
  49    Determines the pathname that would be called by execlp/execvp of PROGNAME.
  50    - If successful, it returns a pathname containing a slash (either absolute
  51      or relative to the current directory).  The returned string can be used
  52      with either execl/execv or execlp/execvp.  It is freshly malloc()ed if it
  53      is != PROGNAME.
  54    - Otherwise, it sets errno and returns NULL.
  55      Specific errno values include:
  56        - ENOENT: means that the program's file was not found.
  57        - EACCES: means that the program's file cannot be accessed (due to some
  58          issue with one of the ancestor directories) or lacks the execute
  59          permissions.
  60        - ENOMEM: means out of memory.
  61    If OPTIMIZE_FOR_EXEC is true, the function saves some work, under the
  62    assumption that the resulting pathname will not be accessed directly,
  63    only through execl/execv or execlp/execvp.
  64
  65    Here, a "slash" means:
  66      - On POSIX systems excluding Cygwin: a '/',
  67      - On Windows, OS/2, DOS platforms: a '/' or '\'. */
  68 extern const char *find_in_given_path (const char *progname, const char *path,
  69                                        const char *directory,
  70                                        bool optimize_for_exec);
  71
  72
  73 #ifdef __cplusplus
  74 }
  75 #endif
  76
  77 #endif /* _FINDPROG_H */