summaryrefslogtreecommitdiff
path: root/coreutils/catv.c (plain)
blob: e3499c59787947c56f64522312d1f46fcce55190
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 source tree.
8 */
9
10/* See "Cat -v considered harmful" at
11 * http://cm.bell-labs.com/cm/cs/doc/84/kp.ps.gz */
12
13//usage:#define catv_trivial_usage
14//usage: "[-etv] [FILE]..."
15//usage:#define catv_full_usage "\n\n"
16//usage: "Display nonprinting characters as ^x or M-x\n"
17//usage: "\n -e End each line with $"
18//usage: "\n -t Show tabs as ^I"
19//usage: "\n -v Don't use ^x or M-x escapes"
20
21#include "libbb.h"
22
23int catv_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
24int catv_main(int argc UNUSED_PARAM, char **argv)
25{
26 int retval = EXIT_SUCCESS;
27 int fd;
28 unsigned opts;
29#define CATV_OPT_e (1<<0)
30#define CATV_OPT_t (1<<1)
31#define CATV_OPT_v (1<<2)
32 typedef char BUG_const_mismatch[
33 CATV_OPT_e == VISIBLE_ENDLINE && CATV_OPT_t == VISIBLE_SHOW_TABS
34 ? 1 : -1
35 ];
36
37 opts = getopt32(argv, "etv");
38 argv += optind;
39#if 0 /* These consts match, we can just pass "opts" to visible() */
40 if (opts & CATV_OPT_e)
41 flags |= VISIBLE_ENDLINE;
42 if (opts & CATV_OPT_t)
43 flags |= VISIBLE_SHOW_TABS;
44#endif
45
46 /* Read from stdin if there's nothing else to do. */
47 if (!argv[0])
48 *--argv = (char*)"-";
49 do {
50 fd = open_or_warn_stdin(*argv);
51 if (fd < 0) {
52 retval = EXIT_FAILURE;
53 continue;
54 }
55 for (;;) {
56 int i, res;
57
58#define read_buf bb_common_bufsiz1
59 res = read(fd, read_buf, COMMON_BUFSIZE);
60 if (res < 0)
61 retval = EXIT_FAILURE;
62 if (res <= 0)
63 break;
64 for (i = 0; i < res; i++) {
65 unsigned char c = read_buf[i];
66 if (opts & CATV_OPT_v) {
67 putchar(c);
68 } else {
69 char buf[sizeof("M-^c")];
70 visible(c, buf, opts);
71 fputs(buf, stdout);
72 }
73 }
74 }
75 if (ENABLE_FEATURE_CLEAN_UP && fd)
76 close(fd);
77 } while (*++argv);
78
79 fflush_stdout_and_exit(retval);
80}
81