use autogen for command line options

libopts/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 */