lib/version.c

   1 /* version.c    version handling
   2  * Copyright (C) 2002, 2003  Simon Josefsson
   3  * Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
   4  *
   5  * This file is part of shishi.
   6  *
   7  * Shishi is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * Shishi 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 GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with shishi; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  */
  22
  23 /* This file is based on src/global.c in libgcrypt */
  24
  25 #include "internal.h"
  26
  27 static const char *
  28 _shishi_parse_version_number (const char *s, int *number)
  29 {
  30   int val = 0;
  31
  32   if (*s == '0' && isdigit (s[1]))
  33     return NULL;                /* leading zeros are not allowed */
  34   for (; isdigit (*s); s++)
  35     {
  36       val *= 10;
  37       val += *s - '0';
  38     }
  39   *number = val;
  40   return val < 0 ? NULL : s;
  41 }
  42
  43
  44 static const char *
  45 _shishi_parse_version_string (const char *s, int *major, int *minor,
  46                               int *micro)
  47 {
  48   s = _shishi_parse_version_number (s, major);
  49   if (!s || *s != '.')
  50     return NULL;
  51   s++;
  52   s = _shishi_parse_version_number (s, minor);
  53   if (!s || *s != '.')
  54     return NULL;
  55   s++;
  56   s = _shishi_parse_version_number (s, micro);
  57   if (!s)
  58     return NULL;
  59   return s;                     /* patchlevel */
  60 }
  61
  62 /**
  63  * shishi_check_version:
  64  * @req_version: version string to compare with, or NULL
  65  *
  66  * Check that the the version of the library is at minimum the one
  67  * given as a string in @req_version.
  68  *
  69  * Return value: the actual version string of the library; NULL if the
  70  * condition is not met.  If %NULL is passed to this function no check
  71  * is done and only the version string is returned.  It is a pretty
  72  * good idea to run this function as soon as possible, because it may
  73  * also intializes some subsystems.  In a multithreaded environment if
  74  * should be called before any more threads are created.
  75  **/
  76 const char *
  77 shishi_check_version (const char *req_version)
  78 {
  79   const char *ver = VERSION;
  80   int my_major, my_minor, my_micro;
  81   int rq_major, rq_minor, rq_micro;
  82   const char *my_plvl, *rq_plvl;
  83
  84   if (!req_version)
  85     return ver;
  86
  87   my_plvl = _shishi_parse_version_string (ver,
  88                                           &my_major, &my_minor, &my_micro);
  89   if (!my_plvl)
  90     return NULL;                /* very strange our own version is bogus */
  91   rq_plvl = _shishi_parse_version_string (req_version, &rq_major, &rq_minor,
  92                                           &rq_micro);
  93   if (!rq_plvl)
  94     return NULL;                /* req version string is invalid */
  95
  96   if (my_major > rq_major
  97       || (my_major == rq_major && my_minor > rq_minor)
  98       || (my_major == rq_major && my_minor == rq_minor
  99           && my_micro > rq_micro)
 100       || (my_major == rq_major && my_minor == rq_minor
 101           && my_micro == rq_micro && strcmp (my_plvl, rq_plvl) >= 0))
 102     {
 103       return ver;
 104     }
 105   return NULL;
 106 }