/************************************************************************ 
   改行コード変換・統一プログラム
					copyright 2004, TKEN
*************************************************************************/
#include <stdio.h>

#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>

static int newline( char * );
static int newline_internal( char *, char *, int size );
static int newline_p( int, int );
static int output_newline( char *, int * );

int
main( int argc, char **argv )
{
	int	i;

	if ( argc < 2 ) {
		fprintf( stderr, "Usage:%s filename, ...\n", argv[0] );
		exit(1);
	}

	for ( i = 1; i < argc; i++ ) {
		newline( argv[i] );
	}

	return 0;
}

static
int
newline( char *filename )
{
	int	ret;
	int	len;

#ifdef _WIN32
	static	struct _stat buf;
#else
	static	struct stat buf;
#endif
	static	char backup_file[1024];

	len = strlen( filename );

	if ( len > 512 ) {
		fprintf( stderr, "Too long filename:%s\n", filename );
		exit(1);
	}

	strcpy( backup_file, filename );
	strcat( backup_file, ".bak" );

#ifdef _WIN32
	ret = _stat( backup_file, &buf );
#else
	ret = stat( backup_file, &buf );
#endif

	if ( ret == 0 ) {
		fprintf( stderr, "<%s> exits!\n", backup_file );
		fprintf( stderr, "please remove or rename <%s>\n", 				backup_file );
		exit(1);
	}

#ifdef _WIN32
	ret = _stat( filename, &buf );
#else
	ret = stat( filename, &buf );
#endif
	if ( ret != 0 ) {
		fprintf( stderr, "<%s> does not exit!\n", filename );
		exit(1);
	}

	newline_internal( filename, backup_file, buf.st_size );

	return 0;
}

static
int
newline_internal( char *srcfile, char *backfile, int size )
{
	char	*filebuf;
	char	*outbuf;
	int	i;
	int	j;
	int	ret;
	int	check;

	FILE *fp1;
	FILE *fp2;

	filebuf = (char *)malloc( size );

	if ( filebuf == NULL ) {
		fprintf( stderr, "Cannot alloc!\n" );
		exit(1);
	}

	outbuf = (char *)malloc( size * 2 );

	if ( filebuf == NULL ) {
		fprintf( stderr, "Cannot alloc!\n" );
		exit(1);
	}

	fp1 = fopen( srcfile, "rb" );

	if ( fp1 == NULL ) {
		fprintf( stderr, "Cannot open %s\n", srcfile );
		exit(1);
	}

	ret = fread( filebuf, size, 1, fp1 );
	if ( ret != 1 ) {
		fprintf( stderr, "Cannot read %s\n", srcfile );
		exit(1);
	}
	fclose( fp1 );

	/* binary check */
	for ( i = 0; i < size; i++ ) {

		if ( filebuf[i] ==  '\0' ) {
			fprintf( stderr, 
				"<%s> seems to be binary file\n", srcfile );
			exit(1);
		}
	}

	fp2= fopen( backfile, "wb" );

	if ( fp2 == NULL ) {
		fprintf( stderr, "Cannot open %s\n", backfile );
		exit(1);
	}

	ret = fwrite( filebuf, size, 1, fp2 );

	if ( ret != 1 ) {
		fprintf( stderr, "Cannot backup %s\n", backfile );
		exit(1);
	}
	fclose( fp2 );
	
	i = 0;
	j = 0;

	while ( i < size ) {
		if ( j >= size * 2) {
			fprintf( stderr, "Panic!\n" );
			exit(1);
		}

		check = newline_p( filebuf[i], filebuf[i+1] );

		if ( check != 0 ) {
			output_newline( outbuf, &j );
			i = i + check;
		}
		else {
			outbuf[j] = filebuf[i], 
			j++;
			i++;
		}
	}

	fp1 = fopen( srcfile, "wb" );

	if ( fp1 == NULL ) {
		fprintf( stderr, "Cannot open %s\n", srcfile );
		exit(1);
	}

	ret = fwrite( outbuf, j, 1, fp1 );
	if ( ret != 1 ) {
		fprintf( stderr, "Cannot write %s\n", srcfile );
		exit(1);
	}

	free( filebuf );
	free( outbuf );

	fclose( fp1 );

	return 1;
}

static
int
newline_p( int c1, int c2 )
{
	if ( c1 == 10 ) {
		/* unix */
		return 1;
	}
		
	if ( ( c1 == 13 ) && ( c2 == 10 ) ) {
		/* dos */
		return 2;
	}

	if ( c1 == 13 )  {
		/* mac */
		return 1;
	}

	return 0;
}

static
int
output_newline( char *buf, int *index )
{

#ifdef _WIN32
	
	buf[*index] = 13;
	(*index)++;
	buf[*index] = 10;
	(*index)++;
#else
	buf[*index] = 10;
	(*index)++;
#endif

	return 1;
}