Added getopt to undpu and -c arguement for output to stdout

undpu.c

@@ -2,23 +2,39 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <getopt.h>
 
 const char compare_string[] = "DOUBLEPLUS UNZIP, FACTOR=";
 
 int main (int argc, char **argv){
 	FILE *bob, *joe;
-	int factor, thing, i;
+	int modifier, factor, thing, i;
+	int out = 0;
 	char output[FILENAME_MAX];
-	if(argc < 2){
+	while((modifier=getopt(argc,argv,"c"))+1){
+		switch(modifier){
+		case 'c':
+			joe=stdout;
+			out = 1;
+			break;
+		default:
+			fprintf(stderr,"modifier=%d\n",modifier);
+			fputs("You're going to have to be clearer about what you want.\n",stderr);
+			return EXIT_FAILURE;
+		}
+	}
+	argc-=optind;
+	argv+=optind;
+	if(argc < 1){
 		fputs("I pity the fool who don't have an input file!\n",stderr);
 		return EXIT_FAILURE;
 	}
-	if(strlen(argv[1]) <= 4 || strcmp(argv[1] + strlen(argv[1]) - 4, ".dpu"))
+	if(strlen(argv[0]) <= 4 || strcmp(argv[0] + strlen(argv[0]) - 4, ".dpu"))
 	{
 		fputs("Where's the rest of the filename?\n", stderr);
 		return EXIT_FAILURE;
 	}
-	if((bob = fopen(argv[1],"r"))==NULL){
+	if((bob = fopen(argv[0],"r"))==NULL){
 		fputs("That's no input file, THAT'S A SPACE STATION!\n",stderr);
 		return EXIT_FAILURE;
 	}
@@ -41,10 +57,12 @@ int main (int argc, char **argv){
 			return EXIT_FAILURE;
 		}
 	}
-	strncpy(output,argv[1],strlen(argv[1])-4);
-	if((joe = fopen(output,"w"))==NULL){
-		fputs("Ummm, the output file doesn't work.\n",stderr);
-		return EXIT_FAILURE;
+	if(!out){
+		strncpy(output,argv[0],strlen(argv[0])-4);
+		if((joe = fopen(output,"w"))==NULL){
+			fputs("Ummm, the output file doesn't work.\n",stderr);
+			return EXIT_FAILURE;
+		}
 	}
 	while((thing=fgetc(bob))!=EOF){
 		fputc(thing,joe);