DoublePlusUnzip/dpu.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <getopt.h>

int main (int argc, char **argv){
	char name[FILENAME_MAX];
	FILE *bob,*joe,*moe;
	int thing, factor, arg;
	int modifier;
	factor=0;
	while((modifier=getopt(argc,argv,"0123456789"))+1){
		switch(modifier){
		case '0': case '1': case '2': case '3': case '4':
		case '5': case '6': case '7': case '8': case '9':
			factor=factor*10+modifier-'0';
			break;
		default:
			fputs("You're going to have to be clearer about what you want.\n",stderr);
			return EXIT_FAILURE;
		}
	}
	if(factor==0){
		factor=9;
	}
	argc-=optind;
	argv+=optind;
	arg=0;
	if(argc<1){
		fputs("I pity the fool who don't have an input file!\n",stderr);
		return EXIT_FAILURE;
	}
	if(argc>1){
		fputs("Be patient, one thing at a time!\n",stderr);
	}
	if(strlen(argv[arg]) >= FILENAME_MAX - 4)
	{
		fputs("It's a filename, not a novel.\n", stderr);
		return EXIT_FAILURE;
	}
	strlcpy(name,argv[arg],sizeof(name));
	strlcat(name,".dpu",sizeof(name));	
	if((bob = fopen(argv[arg],"r"))==NULL){
		fputs("NO YOU FOOL, A REAL ONE!\n",stderr);
		return EXIT_FAILURE;
	}
	if((joe = fopen(name,"w"))==NULL){
		fputs("Ummm, you seem to have an unwritable file or directory or something silly called the output file, this is dumb. Please stop.\n",stderr);
		return EXIT_FAILURE;
	} 
	if((moe = fopen("/dev/urandom","r"))==NULL){
		fputs("So, you aren't random enough. Annoying.\n",stderr);
		return EXIT_FAILURE;
	}
	fprintf(joe,"DOUBLEPLUS UNZIP, FACTOR=%d;",factor);
	while((thing=fgetc(bob))!=EOF){
		int i;
		if((fputc(thing,joe))==EOF){
			perror("fputc(thing,joe)");
			fputs("problematic\n",stderr);
			return EXIT_FAILURE;
		}
		for(i=0;i<factor;i++){
			thing=fgetc(moe);
			fputc(thing,joe);
		}
	}
	return 0;
}