dist/ntp/sntp/libopts/pgusage.c

   1 /*      $NetBSD$        */
   2
   3
   4 /*
   5  *  Id: pgusage.c,v 4.12 2007/04/28 22:19:23 bkorb Exp
   6  * Time-stamp:      "2006-07-16 08:13:26 bkorb"
   7  *
   8  *   Automated Options Paged Usage module.
   9  *
  10  *  This routine will run run-on options through a pager so the
  11  *  user may examine, print or edit them at their leisure.
  12  */
  13
  14 /*
  15  *  Automated Options copyright 1992-2007 Bruce Korb
  16  *
  17  *  Automated Options is free software.
  18  *  You may redistribute it and/or modify it under the terms of the
  19  *  GNU General Public License, as published by the Free Software
  20  *  Foundation; either version 2, or (at your option) any later version.
  21  *
  22  *  Automated Options is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with Automated Options.  See the file "COPYING".  If not,
  29  *  write to:  The Free Software Foundation, Inc.,
  30  *             51 Franklin Street, Fifth Floor,
  31  *             Boston, MA  02110-1301, USA.
  32  *
  33  * As a special exception, Bruce Korb gives permission for additional
  34  * uses of the text contained in his release of AutoOpts.
  35  *
  36  * The exception is that, if you link the AutoOpts library with other
  37  * files to produce an executable, this does not by itself cause the
  38  * resulting executable to be covered by the GNU General Public License.
  39  * Your use of that executable is in no way restricted on account of
  40  * linking the AutoOpts library code into it.
  41  *
  42  * This exception does not however invalidate any other reasons why
  43  * the executable file might be covered by the GNU General Public License.
  44  *
  45  * This exception applies only to the code released by Bruce Korb under
  46  * the name AutoOpts.  If you copy code from other sources under the
  47  * General Public License into a copy of AutoOpts, as the General Public
  48  * License permits, the exception does not apply to the code that you add
  49  * in this way.  To avoid misleading anyone as to the status of such
  50  * modified files, you must delete this exception notice from them.
  51  *
  52  * If you write modifications of your own for AutoOpts, it is your choice
  53  * whether to permit this exception to apply to your modifications.
  54  * If you do not wish that, delete this exception notice.
  55  */
  56
  57 tePagerState pagerState = PAGER_STATE_INITIAL;
  58
  59 /*=export_func  optionPagedUsage
  60  * private:
  61  *
  62  * what:  Decipher a boolean value
  63  * arg:   + tOptions* + pOpts    + program options descriptor +
  64  * arg:   + tOptDesc* + pOptDesc + the descriptor for this arg +
  65  *
  66  * doc:
  67  *  Run the usage output through a pager.
  68  *  This is very handy if it is very long.
  69 =*/
  70 void
  71 optionPagedUsage( tOptions* pOptions, tOptDesc* pOD )
  72 {
  73 #if defined(__windows__) && !defined(__CYGWIN__)
  74     (*pOptions->pUsageProc)( pOptions, EXIT_SUCCESS );
  75 #else
  76     static pid_t     my_pid;
  77     char zPageUsage[ 1024 ];
  78
  79     /*
  80      *  IF we are being called after the usage proc is done
  81      *     (and thus has called "exit(2)")
  82      *  THEN invoke the pager to page through the usage file we created.
  83      */
  84     switch (pagerState) {
  85     case PAGER_STATE_INITIAL:
  86     {
  87         my_pid  = getpid();
  88 #ifdef HAVE_SNPRINTF
  89         snprintf(zPageUsage, sizeof(zPageUsage), "/tmp/use.%lu", (tAoUL)my_pid);
  90 #else
  91         sprintf( zPageUsage, "/tmp/use.%lu", (tAoUL)my_pid );
  92 #endif
  93         unlink( zPageUsage );
  94
  95         /*
  96          *  Set usage output to this temporary file
  97          */
  98         option_usage_fp = fopen( zPageUsage, "w" FOPEN_BINARY_FLAG );
  99         if (option_usage_fp == NULL)
 100             _exit( EXIT_FAILURE );
 101
 102         pagerState = PAGER_STATE_READY;
 103
 104         /*
 105          *  Set up so this routine gets called during the exit logic
 106          */
 107         atexit( (void(*)(void))optionPagedUsage );
 108
 109         /*
 110          *  The usage procedure will now put the usage information into
 111          *  the temporary file we created above.
 112          */
 113         (*pOptions->pUsageProc)( pOptions, EXIT_SUCCESS );
 114
 115         /*NOTREACHED*/
 116         _exit( EXIT_FAILURE );
 117     }
 118
 119     case PAGER_STATE_READY:
 120     {
 121         tSCC zPage[]  = "%1$s /tmp/use.%2$lu ; rm -f /tmp/use.%2$lu";
 122         tCC* pzPager  = (tCC*)getenv( "PAGER" );
 123
 124         /*
 125          *  Use the "more(1)" program if "PAGER" has not been defined
 126          */
 127         if (pzPager == NULL)
 128             pzPager = "more";
 129
 130         /*
 131          *  Page the file and remove it when done.
 132          */
 133 #ifdef HAVE_SNPRINTF
 134         snprintf(zPageUsage, sizeof(zPageUsage), zPage, pzPager, (tAoUL)my_pid);
 135 #else
 136         sprintf( zPageUsage, zPage, pzPager, (tAoUL)my_pid );
 137 #endif
 138         fclose( stderr );
 139         dup2( STDOUT_FILENO, STDERR_FILENO );
 140
 141         (void)system( zPageUsage );
 142     }
 143
 144     case PAGER_STATE_CHILD:
 145         /*
 146          *  This is a child process used in creating shell script usage.
 147          */
 148         break;
 149     }
 150 #endif
 151 }
 152
 153 /*
 154  * Local Variables:
 155  * mode: C
 156  * c-file-style: "stroustrup"
 157  * indent-tabs-mode: nil
 158  * End:
 159  * end of autoopts/pgusage.c */