1/* vi: set sw=4 ts=4: */
2/*
3 * cat -v implementation for busybox
4 *
5 * Copyright (C) 2006 Rob Landley <rob@landley.net>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8 */
9
10/* See "Cat -v considered harmful" at
11 * http://cm.bell-labs.com/cm/cs/doc/84/kp.ps.gz */
12
13#include "libbb.h"
14
15int catv_main(int argc, char **argv);
16int catv_main(int argc, char **argv)
17{
18	int retval = EXIT_SUCCESS;
19	int fd;
20	unsigned flags;
21
22	flags = getopt32(argv, "etv");
23#define CATV_OPT_e (1<<0)
24#define CATV_OPT_t (1<<1)
25#define CATV_OPT_v (1<<2)
26	flags ^= CATV_OPT_v;
27	argv += optind;
28
29	/* Read from stdin if there's nothing else to do. */
30	fd = 0;
31	if (!argv[0]) {
32		argv--;
33		goto jump_in;
34	}
35	do {
36		fd = open_or_warn(*argv, O_RDONLY);
37		if (fd < 0) {
38			retval = EXIT_FAILURE;
39			continue;
40		}
41 jump_in:
42		for (;;) {
43			int i, res;
44
45#define read_buf bb_common_bufsiz1
46			res = read(fd, read_buf, COMMON_BUFSIZE);
47			if (res < 0)
48				retval = EXIT_FAILURE;
49			if (res < 1)
50				break;
51			for (i = 0; i < res; i++) {
52				unsigned char c = read_buf[i];
53
54				if (c > 126 && (flags & CATV_OPT_v)) {
55					if (c == 127) {
56						printf("^?");
57						continue;
58					}
59					printf("M-");
60					c -= 128;
61				}
62				if (c < 32) {
63					if (c == 10) {
64						if (flags & CATV_OPT_e)
65							putchar('$');
66					} else if (flags & (c==9 ? CATV_OPT_t : CATV_OPT_v)) {
67						printf("^%c", c+'@');
68						continue;
69					}
70				}
71				putchar(c);
72			}
73		}
74		if (ENABLE_FEATURE_CLEAN_UP && fd)
75			close(fd);
76	} while (*++argv);
77
78	fflush_stdout_and_exit(retval);
79}
80