external/bsd/ntp/dist/sntp/libopts/pgusage.c

   1 /*      $NetBSD$        */
   2
   3
   4 /*
   5  *  Id: da09fc943da953195b243b7697fdbf5127f5b6c2
   6  * Time-stamp:      "2009-11-01 11:52:51 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  *  This file is part of AutoOpts, a companion to AutoGen.
  14  *  AutoOpts is free software.
  15  *  AutoOpts is copyright (c) 1992-2009 by Bruce Korb - all rights reserved
  16  *
  17  *  AutoOpts is available under any one of two licenses.  The license
  18  *  in use must be one of these two and the choice is under the control
  19  *  of the user of the license.
  20  *
  21  *   The GNU Lesser General Public License, version 3 or later
  22  *      See the files "COPYING.lgplv3" and "COPYING.gplv3"
  23  *
  24  *   The Modified Berkeley Software Distribution License
  25  *      See the file "COPYING.mbsd"
  26  *
  27  *  These files have the following md5sums:
  28  *
  29  *  43b91e8ca915626ed3818ffb1b71248b pkg/libopts/COPYING.gplv3
  30  *  06a1a2e4760c90ea5e1dad8dfaac4d39 pkg/libopts/COPYING.lgplv3
  31  *  66a5cedaf62c4b2637025f049f9b826f pkg/libopts/COPYING.mbsd
  32  */
  33
  34 tePagerState pagerState = PAGER_STATE_INITIAL;
  35
  36 /*=export_func  optionPagedUsage
  37  * private:
  38  *
  39  * what:  Decipher a boolean value
  40  * arg:   + tOptions* + pOpts    + program options descriptor +
  41  * arg:   + tOptDesc* + pOptDesc + the descriptor for this arg +
  42  *
  43  * doc:
  44  *  Run the usage output through a pager.
  45  *  This is very handy if it is very long.
  46  *  This is disabled on platforms without a working fork() function.
  47 =*/
  48 void
  49 optionPagedUsage( tOptions* pOptions, tOptDesc* pOD )
  50 {
  51 #if ! defined(HAVE_WORKING_FORK)
  52     if ((pOD->fOptState & OPTST_RESET) != 0)
  53         return;
  54
  55     (*pOptions->pUsageProc)( pOptions, EXIT_SUCCESS );
  56 #else
  57     static pid_t     my_pid;
  58     char zPageUsage[ 1024 ];
  59
  60     /*
  61      *  IF we are being called after the usage proc is done
  62      *     (and thus has called "exit(2)")
  63      *  THEN invoke the pager to page through the usage file we created.
  64      */
  65     switch (pagerState) {
  66     case PAGER_STATE_INITIAL:
  67     {
  68         if ((pOD->fOptState & OPTST_RESET) != 0)
  69             return;
  70
  71         my_pid  = getpid();
  72 #ifdef HAVE_SNPRINTF
  73         snprintf(zPageUsage, sizeof(zPageUsage), "/tmp/use.%lu", (tAoUL)my_pid);
  74 #else
  75         sprintf( zPageUsage, "/tmp/use.%lu", (tAoUL)my_pid );
  76 #endif
  77         unlink( zPageUsage );
  78
  79         /*
  80          *  Set usage output to this temporary file
  81          */
  82         option_usage_fp = fopen( zPageUsage, "w" FOPEN_BINARY_FLAG );
  83         if (option_usage_fp == NULL)
  84             _exit( EXIT_FAILURE );
  85
  86         pagerState = PAGER_STATE_READY;
  87
  88         /*
  89          *  Set up so this routine gets called during the exit logic
  90          */
  91         atexit( (void(*)(void))optionPagedUsage );
  92
  93         /*
  94          *  The usage procedure will now put the usage information into
  95          *  the temporary file we created above.
  96          */
  97         (*pOptions->pUsageProc)( pOptions, EXIT_SUCCESS );
  98
  99         /* NOTREACHED */
 100         _exit( EXIT_FAILURE );
 101     }
 102
 103     case PAGER_STATE_READY:
 104     {
 105         tSCC zPage[]  = "%1$s /tmp/use.%2$lu ; rm -f /tmp/use.%2$lu";
 106         tCC* pzPager  = (tCC*)getenv( "PAGER" );
 107
 108         /*
 109          *  Use the "more(1)" program if "PAGER" has not been defined
 110          */
 111         if (pzPager == NULL)
 112             pzPager = "more";
 113
 114         /*
 115          *  Page the file and remove it when done.
 116          */
 117 #ifdef HAVE_SNPRINTF
 118         snprintf(zPageUsage, sizeof(zPageUsage), zPage, pzPager, (tAoUL)my_pid);
 119 #else
 120         sprintf( zPageUsage, zPage, pzPager, (tAoUL)my_pid );
 121 #endif
 122         fclose( stderr );
 123         dup2( STDOUT_FILENO, STDERR_FILENO );
 124
 125         (void)system( zPageUsage );
 126     }
 127
 128     case PAGER_STATE_CHILD:
 129         /*
 130          *  This is a child process used in creating shell script usage.
 131          */
 132         break;
 133     }
 134 #endif
 135 }
 136
 137 /*
 138  * Local Variables:
 139  * mode: C
 140  * c-file-style: "stroustrup"
 141  * indent-tabs-mode: nil
 142  * End:
 143  * end of autoopts/pgusage.c */