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Diffstat (limited to 'autoopts/pgusage.c')
-rw-r--r-- | autoopts/pgusage.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/autoopts/pgusage.c b/autoopts/pgusage.c new file mode 100644 index 0000000..7eae2b0 --- /dev/null +++ b/autoopts/pgusage.c @@ -0,0 +1,132 @@ + +/** + * \file pgusage.c + * + * Time-stamp: "2012-02-28 19:49:32 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) 1992-2012 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(); + snprintf(zPageUsage, sizeof(zPageUsage), TMP_USAGE_FMT, (tAoUL)my_pid); + 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: + { + tCC* pzPager = (tCC*)getenv(PAGER_NAME); + + /* + * Use the "more(1)" program if "PAGER" has not been defined + */ + if (pzPager == NULL) + pzPager = MORE_STR; + + /* + * Page the file and remove it when done. + */ + snprintf(zPageUsage, sizeof(zPageUsage), PAGE_USAGE_FMT, pzPager, + (tAoUL)my_pid); + 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 */ |