/*
 *    	framefree -
 * 		Do you like Netscape and beyond, but HATE
 *	"frames"?  This program will patch the netscape 
 *	executable to make it forget that frames ever existed!!   
 *
 *	To compile:
		cc framefree.c -o framefree 
 *
 *	To use first exit netscape, then do:
 *
		su
		./framefree `which netscape`
		exit
		netscape
 *
 *	This changes the first letter of the strings "frameset" and 
 *	"noframes" to 'x'. This is technique still allows netscape's 
 *	"View Document Info" to work even though it uses frames!
 *	Tre' swank until Netscape starts encrypting their tag names. 
 *	(Maybe Netscape 3.1).
 *
 *			Paul Haeberli - 1996
 *
 */
#include "stdio.h"

#define READSIZE 	20000
char buf[READSIZE];

main(argc,argv)
int argc;
char **argv;
{
    int pos;
    char old[7], new[7];
  
    if(argc<2) {
	fprintf(stderr,"usage: su\n");
	fprintf(stderr,"       ./framefree `which netscape`\n");
	fprintf(stderr,"       exit\n");
	fprintf(stderr,"       netscape\n");
	exit(1);
    }
    delete(argv[1],"frameset");
    delete(argv[1],"noframes");
    exit(0);
}

delete(filename,pattern)
char *filename;
char *pattern;
{
    FILE *f;
    int len, i;
    char new[512];

    f = fopen(filename,"r+");
    if(!f) {
	fprintf(stderr,"framefree: can't open [%s] for read write!\n",filename);
	exit(1);
    }
    len = strlen(pattern);
    for(i=0; i<len; i++) { /* make the first letter 'x' */
	if(i==0)
	    new[i] = 'x';
	else
	    new[i] = pattern[i];
    }
    change(f,pattern,new,len);
    fclose(f);
}

int bsame(a,b,n)
char *a, *b;
int n;
{
    while(n--) {
	if(*a++ != *b++)
	    return 0;
    }
    return 1;
}

change(f,opat,npat,patlen)
FILE *f;
char *opat, *npat;
int patlen;
{
    int i, j, pos, touched, rn, n;
    char *sptr, *dptr;

    pos = 0;
    while(1) {
	fseek(f,pos,SEEK_SET);
	rn = fread(buf,1,READSIZE,f);
	if(rn<=0) {
	    fclose(f);
	    return;
	}
	touched = 0;
	n = rn-patlen;
	sptr = buf;
	for(i=0; i<=n; i++) {
	    if(sptr[0] == opat[0]) {
		if(bsame(sptr,opat,patlen)) {
		    for(j=0; j<patlen; j++)
			sptr[j] = npat[j];
		    fprintf(stderr,"framefree: fixed one spot\n");
		    touched = 1;
		}
	    }
	    sptr++;
	}
	if(touched) {
	    fseek(f,pos,SEEK_SET);
	    n = fwrite(buf,1,rn,f);
	}
	pos += READSIZE-patlen;
    }
}