string/envz.h

   1 /* Routines for dealing with '\0' separated environment vectors
   2    Copyright (C) 1995, 1996 Free Software Foundation, Inc.
   3    Written by Miles Bader <miles@gnu.ai.mit.edu>
   4
   5    This program is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU General Public License as
   7    published by the Free Software Foundation; either version 2, or (at
   8    your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful, but
  11    WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    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, write to the Free Software
  17    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
  18
  19 #ifndef __ENVZ_H__
  20
  21 #define __ENVZ_H__      1
  22 #include <features.h>
  23
  24 #include <errno.h>
  25
  26 /* Envz's are argz's too, and should be created etc., using the same
  27    routines.  */
  28 #include <argz.h>
  29
  30 /* Returns a pointer to the entry in ENVZ for NAME, or 0 if there is none.  */
  31 extern char *envz_entry __P ((__const char *__envz, size_t __envz_len,
  32                               __const char *__name));
  33
  34 /* Returns a pointer to the value portion of the entry in ENVZ for NAME, or 0
  35    if there is none.  */
  36 extern char *envz_get __P ((__const char *__envz, size_t __envz_len,
  37                             __const char *__name));
  38
  39 /* Adds an entry for NAME with value VALUE to ENVZ & ENVZ_LEN.  If an entry
  40    with the same name already exists in ENVZ, it is removed.  If VALUE is
  41    NULL, then the new entry will a special null one, for which envz_get will
  42    return NULL, although envz_entry will still return an entry; this is handy
  43    because when merging with another envz, the null entry can override an
  44    entry in the other one.  Null entries can be removed with envz_strip ().  */
  45 extern error_t envz_add __P ((char **__envz, size_t *__envz_len,
  46                               __const char *__name, __const char *__value));
  47
  48 /* Adds each entry in ENVZ2 to ENVZ & ENVZ_LEN, as if with envz_add().  If
  49    OVERRIDE is true, then values in ENVZ2 will supercede those with the same
  50    name in ENV, otherwise not.  */
  51 extern error_t envz_merge __P ((char **__envz, size_t *__envz_len,
  52                                 __const char *__envz2, size_t __envz2_len,
  53                                 int __override));
  54
  55 /* Remove null entries.  */
  56 extern void envz_strip __P ((char **__envz, size_t *__envz_len));
  57
  58 #endif /* __ENVZ_H__ */