/*
** uncrlf.c - A small program to convert text files to the UNIX
**            end-of-line convention. Handles PC (CR-LF), Mac (CR)
**            and strange (LF-CR) files automatically.
**
** Copyright (c) 2000 Peter Eriksson <pen@lysator.liu.se>
**
** This program is free software; you can redistribute it and/or
** modify it as you wish - as long as you don't claim that you wrote
** it.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
**
** Usage:
**         uncrlf <file-1> [... <file-N>]
**
*/

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


int lf_seen = 0;
int cr_seen = 0;

char *
my_dirname(const char *path,
	   char *buf)
{
    char *cp;


    cp = strrchr(path, '/');
    if (cp == NULL)
    {
	strcpy(buf, ".");
	return buf;
    }

    strncpy(buf, path, cp-path);
    buf[cp-path] = '\0';

    return buf;
}


int
fix_crlf(FILE *in,
	 FILE *out)
{
    int c;

    while ((c = getc(in)) != EOF)
	switch (c)
	{
	  case 10:
	    if (lf_seen)
		putc(10, out);
	    else if (cr_seen)
	    {
		putc(10, out);
		cr_seen = 0;
	    }
	    else
		lf_seen = 1;
	    break;

	  case 13:
	    if (cr_seen)
		putc(10, out);
	    else if (lf_seen)
	    {
		putc(10, out);
		lf_seen = 0;
	    }
	    else
		cr_seen = 1;
	    break;

	  default:
	    if (lf_seen)
	    {
		putc(10, out);
		lf_seen = 0;
	    }

	    if (cr_seen)
	    {
		putc(10, out);
		cr_seen = 0;
	    }
	    
	    putc(c, out);
	}

    if (lf_seen)
    {
	putc(10, out);
	lf_seen = 0;
    }
	    
    if (cr_seen)
    {
	putc(10, out);
	cr_seen = 0;
    }
	    
    return 0;
}



int
main(int argc,
     char *argv[])
{
    int i;
    char buf[2048];
    FILE *in, *out;
   
    
    if (argc == 1)
    {
	if (fix_crlf(stdin, stdout) < 0)
	{
	    fprintf(stderr, "%s: conversion failed\n", argv[0]);
	    exit(1);
	}
    }
    else
    {
	for (i = 1; i < argc; i++)
	{
	    my_dirname(argv[i], buf);
	    sprintf(buf+strlen(buf), "/.tmp.%d", getpid());
	    
	    in = fopen(argv[i], "r");
	    if (in == NULL)
	    {
		fprintf(stderr, "%s: fopen: %s: %s\n",
			argv[0],
			argv[i],
			strerror(errno));
		exit(1);
	    }
	    
	    out = fopen(buf, "w");
	    if (out == NULL)
	    {
		fprintf(stderr, "%s: fopen: %s: %s\n",
			argv[0],
			buf,
			strerror(errno));
		exit(1);
	    }
	    
	    if (fix_crlf(in, out) < 0)
	    {
		fprintf(stderr, "%s: conversion failed\n", argv[0]);
		exit(1);
	    }

	    fclose(in);
	    fclose(out);
	    if (rename(buf, argv[i]) < 0)
	    {
		fprintf(stderr, "%s: rename: %s -> %s: %s",
			argv[0], buf, argv[i],
			strerror(errno));
		exit(1);
	    }
	}
    }

    return 0;
}