# HG changeset patch
# User paulo@twcdns.fastsearch.net
# Date 1270536338 25200
# Node ID 99770a6b967d9dde77c0cb70b8597444f4220c4d
# Parent  fe4b316b43860c30f27b4f653e81902f4f0321fc
rcg.c: use getopt.h and read in regex from arguments; use enum for exit codes

diff -r fe4b316b4386 -r 99770a6b967d rcg.c
--- a/rcg.c	Mon Apr 05 22:37:37 2010 -0700
+++ b/rcg.c	Mon Apr 05 23:45:38 2010 -0700
@@ -5,11 +5,22 @@
 #define __USE_GNU
 #include <string.h>
 
+#include <unistd.h>
+
+#define _GNU_SOURCE
+#include <getopt.h>
+
 const size_t BUFSIZE = 5000;
 
 const char *CLR_START = "-CLR_START-";
 const char *CLR_END = "-CLR_END-";
 
+typedef enum _exit_code {
+	EXIT_OK,
+	EXIT_REALLOC_ERROR,
+	EXIT_ARGS_ERROR,
+} Exit_code;
+
 int re_error(int errcode, const regex_t *re)
 {
 	char *err_string = calloc(BUFSIZE, sizeof(char));
@@ -19,19 +30,49 @@
 	return errcode;
 }
 
-int realloc_error()
+Exit_code realloc_error()
 {
 	fprintf(stderr, "realloc() failure \n");
-	return 1;
+	return EXIT_REALLOC_ERROR;
+}
+
+Exit_code args_error()
+{
+	fprintf(stderr, "Invalid or nonexistent argument. \n");
+	return EXIT_ARGS_ERROR;
+} 
+
+// returns regular expression argument
+char *parseArgs(int argc, char **argv)
+{
+	static struct option long_options[] =
+	{
+		{ 0, 0, 0, 0 },
+	};
+	
+	int c;
+	int l;
+	while ((c = getopt_long(argc, argv, "", long_options, &l)) >= 0)
+	{
+	}
+
+	if (optind >= argc)
+		exit(args_error());
+
+	return argv[optind];
 }
 
 int main(int argc, char **argv)
 {
+	char *re_expression = parseArgs(argc, argv);
+
+	fprintf(stderr, "re_expression = %s \n", re_expression);		//d/ 20100405 PBA
+
 	char *buf = calloc(BUFSIZE, sizeof(char));
 
 	int re_err;
 	regex_t *re = calloc(1, sizeof(regex_t));
-	re_err = regcomp(re, "Hello", REG_EXTENDED);
+	re_err = regcomp(re, re_expression, REG_EXTENDED);
 	if (re_err != 0)
 		exit(re_error(re_err, re));
 
@@ -40,7 +81,6 @@
 	size_t CLR_START_len = strlen(CLR_START);
 	size_t CLR_END_len = strlen(CLR_END);
 
-
 	while (fgets(buf, BUFSIZE, stdin))
 	{
 		int so = -1;
@@ -51,7 +91,7 @@
 		unsigned int out_pos = 0;
 		unsigned int buf_pos = 0;
 
-		while (re_err != REG_NOMATCH)
+		for (re_err = 0; re_err != REG_NOMATCH;)
 		{
 			re_err = regexec(re, &buf[buf_pos], 1, rem, 0);
 
@@ -92,5 +132,5 @@
 		free(out);
 	}
 
-	return 0;
+	return EXIT_OK;
 }