/* vi: set sw=4 ts=4:
 *
 * dos2unix.c - convert newline format
 *
 * Copyright 2012 Rob Landley <rob@landley.net>

USE_DOS2UNIX(NEWTOY(dos2unix, NULL, TOYFLAG_BIN))
USE_DOS2UNIX(OLDTOY(unix2dos, dos2unix, NULL, TOYFLAG_BIN))

config DOS2UNIX
	bool "dos2unix/unix2dos"
	default y
	help
	  usage: dos2unix/unix2dos [file...]

	  Convert newline format between dos (\r\n) and unix (just \n)
	  If no files listed copy from stdin, "-" is a synonym for stdin.
*/

#include "toys.h"

DEFINE_GLOBALS(
	char *tempfile;
)

#define TT this.dos2unix

static void do_dos2unix(int fd, char *name)
{
	char c = toys.which->name[0];
	int outfd = 1, catch = 0;

	if (fd) outfd = copy_tempfile(fd, name, &TT.tempfile);

	for (;;) {
		int len, in, out;

		len = read(fd, toybuf+(sizeof(toybuf)/2), sizeof(toybuf)/2);
		if (len<0) {
			perror_msg("%s",name);
			toys.exitval = 1;
		}
		if (len<1) break;

		for (in = out = 0; in < len; in++) {
			char x = toybuf[in+sizeof(toybuf)/2];

			// Drop \r only if followed by \n in dos2unix mode
			if (catch) {
				if (c == 'u' || x != '\n') toybuf[out++] = '\r';
				catch = 0;
			// Add \r only if \n not after \r in unix2dos mode
			} else if (c == 'u' && x == '\n') toybuf[out++] = '\r';

			if (x == '\r') catch++;
			else toybuf[out++] = x;
		}
		xwrite(outfd, toybuf, out);
	}
	if (catch) xwrite(outfd, "\r", 1);

	if (fd) replace_tempfile(-1, outfd, &TT.tempfile);
}

void dos2unix_main(void)
{
	loopfiles(toys.optargs, do_dos2unix);
}