/*
 *                              DOS2UNIX.C
 *
 * Clean out cr/lf combinations in a file but keep it's original
 * date/time stamp.
 *
 * - to compile type gcc -o d2u dos2unix.c
 */

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifndef TRUE
#	define TRUE  (1)
#	define FALSE (0)
#endif

#if MSDOS
#	define link(x,y) rename (x, y)
#	define R_CNTRL   "rb"
#	define W_CNTRL   "wb"
#else
#	define R_CNTRL   "r"
#	define W_CNTRL   "w"
#endif


struct stat s_buf;

/**************************************************************************/
int main (int argc, char **argv)
{
	char *path;
	while (--argc>0)
	{
		if (stat (path=*++argv, &s_buf) != -1)
		{
			printf ("Dos2Unix: Cleaning file %s ...\n", path);
			if (dos2u (path))
			{
				fprintf (stderr, "Dos2Unix: Problems cleaning file %s\n", path);
			}
		}
		else
		{
			fprintf (stderr, "Dos2Unix: Can't stat '%s'\n", path);
		}
	}
}

/**************************************************************************/
int dos2u(char *path)
{
	FILE *in, *out;
	int ch,
		rval = FALSE;
	char temppath [16];
	struct utimbuf { time_t actime, modtime; } ut_buf;
	
	strcpy (temppath, "./clntmp");
#if !defined (MSDOS)
	strcat (temppath, "XXXXXX");
	mkstemp (temppath);
#endif	
	if ((in=fopen (path, R_CNTRL)) == (FILE *) 0)
		return TRUE;
	if ((out=fopen (temppath, W_CNTRL)) == (FILE *) 0)
	{
		fclose (in);
		return TRUE;
	}
	while ((ch = getc (in)) != EOF){
        if ((ch == '\t') && (fputs("    ", out)==EOF))
        {
            rval = TRUE;
            break;
        }
		if ((ch != '\015' && ch != '\032') &&
			(putc(ch, out)==EOF)           )
		{
			rval = TRUE;
			break;
		}
	}

	if (fclose (in) == EOF){
		rval = TRUE;
	}

	if (fclose (out) == EOF){
		rval = TRUE;
	}
	ut_buf.actime = s_buf.st_atime;
	ut_buf.modtime = s_buf.st_mtime;
	if (utime (temppath, &ut_buf) == -1){
		rval = TRUE;
	}
	if (unlink (path) == -1){
		rval = TRUE;
	}
	if (rval)
	{
		unlink (temppath);
		return TRUE;
	}
	if (link (temppath,path) == -1)
	{
		fprintf (stderr, "Dos2Unix: Problems renaming '%s' to '%s'\n", temppath, path);
		fprintf (stderr, "          However, file '%s' remains\n", temppath);
		exit (1);
	}
	unlink (temppath);
	return FALSE;
}
/**************************************************************************/