/**
* \file pgusage.c
*
* Time-stamp: "2011-03-25 17:54:41 bkorb"
*
* Automated Options Paged Usage module.
*
* This routine will run run-on options through a pager so the
* user may examine, print or edit them at their leisure.
*
* This file is part of AutoOpts, a companion to AutoGen.
* AutoOpts is free software.
* AutoOpts is Copyright (c) 1992-2011 by Bruce Korb - all rights reserved
*
* AutoOpts is available under any one of two licenses. The license
* in use must be one of these two and the choice is under the control
* of the user of the license.
*
* The GNU Lesser General Public License, version 3 or later
* See the files "COPYING.lgplv3" and "COPYING.gplv3"
*
* The Modified Berkeley Software Distribution License
* See the file "COPYING.mbsd"
*
* These files have the following md5sums:
*
* 43b91e8ca915626ed3818ffb1b71248b pkg/libopts/COPYING.gplv3
* 06a1a2e4760c90ea5e1dad8dfaac4d39 pkg/libopts/COPYING.lgplv3
* 66a5cedaf62c4b2637025f049f9b826f pkg/libopts/COPYING.mbsd
*/
/*=export_func optionPagedUsage
* private:
*
* what: Decipher a boolean value
* arg: + tOptions* + pOpts + program options descriptor +
* arg: + tOptDesc* + pOptDesc + the descriptor for this arg +
*
* doc:
* Run the usage output through a pager.
* This is very handy if it is very long.
* This is disabled on platforms without a working fork() function.
=*/
void
optionPagedUsage(tOptions* pOptions, tOptDesc* pOD)
{
#if ! defined(HAVE_WORKING_FORK)
if ((pOD->fOptState & OPTST_RESET) != 0)
return;
(*pOptions->pUsageProc)(pOptions, EXIT_SUCCESS);
#else
static pid_t my_pid;
char zPageUsage[ 1024 ];
/*
* IF we are being called after the usage proc is done
* (and thus has called "exit(2)")
* THEN invoke the pager to page through the usage file we created.
*/
switch (pagerState) {
case PAGER_STATE_INITIAL:
{
if ((pOD->fOptState & OPTST_RESET) != 0)
return;
my_pid = getpid();
#ifdef HAVE_SNPRINTF
snprintf(zPageUsage, sizeof(zPageUsage), "/tmp/use.%lu", (tAoUL)my_pid);
#else
sprintf(zPageUsage, "/tmp/use.%lu", (tAoUL)my_pid);
#endif
unlink(zPageUsage);
/*
* Set usage output to this temporary file
*/
option_usage_fp = fopen(zPageUsage, "w" FOPEN_BINARY_FLAG);
if (option_usage_fp == NULL)
_exit(EXIT_FAILURE);
pagerState = PAGER_STATE_READY;
/*
* Set up so this routine gets called during the exit logic
*/
atexit((void(*)(void))optionPagedUsage);
/*
* The usage procedure will now put the usage information into
* the temporary file we created above.
*/
(*pOptions->pUsageProc)(pOptions, EXIT_SUCCESS);
/* NOTREACHED */
_exit(EXIT_FAILURE);
}
case PAGER_STATE_READY:
{
tSCC zPage[] = "%1$s /tmp/use.%2$lu ; rm -f /tmp/use.%2$lu";
tCC* pzPager = (tCC*)getenv("PAGER");
/*
* Use the "more(1)" program if "PAGER" has not been defined
*/
if (pzPager == NULL)
pzPager = "more";
/*
* Page the file and remove it when done.
*/
#ifdef HAVE_SNPRINTF
snprintf(zPageUsage, sizeof(zPageUsage), zPage, pzPager, (tAoUL)my_pid);
#else
sprintf(zPageUsage, zPage, pzPager, (tAoUL)my_pid);
#endif
fclose(stderr);
dup2(STDOUT_FILENO, STDERR_FILENO);
(void)system(zPageUsage);
}
case PAGER_STATE_CHILD:
/*
* This is a child process used in creating shell script usage.
*/
break;
}
#endif
}
/*
* Local Variables:
* mode: C
* c-file-style: "stroustrup"
* indent-tabs-mode: nil
* End:
* end of autoopts/pgusage.c */
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