1 /* vi: set sw=4 ts=4: */
3 * cat implementation for busybox
5 * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
7 * Licensed under GPLv2, see file LICENSE in this source tree.
10 //config: bool "cat (5.6 kb)"
13 //config: cat is used to concatenate files and print them to the standard
14 //config: output. Enable this option if you wish to enable the 'cat' utility.
16 //config:config FEATURE_CATN
17 //config: bool "Enable -n and -b options"
19 //config: depends on CAT
21 //config: -n numbers all output lines while -b numbers nonempty output lines.
23 //config:config FEATURE_CATV
24 //config: bool "cat -v[etA]"
26 //config: depends on CAT
28 //config: Display nonprinting characters as escape sequences
30 //applet:IF_CAT(APPLET(cat, BB_DIR_BIN, BB_SUID_DROP))
32 //kbuild:lib-$(CONFIG_CAT) += cat.o
34 /* BB_AUDIT SUSv3 compliant */
35 /* http://www.opengroup.org/onlinepubs/007904975/utilities/cat.html */
37 //usage:#if ENABLE_FEATURE_CATN || ENABLE_FEATURE_CATV
38 //usage:#define cat_trivial_usage
39 //usage: "[-" IF_FEATURE_CATN("nb") IF_FEATURE_CATV("vteA") "] [FILE]..."
41 //usage:#define cat_trivial_usage
44 //usage:#define cat_full_usage "\n\n"
45 //usage: "Print FILEs to stdout\n"
46 //usage: IF_FEATURE_CATN(
47 //usage: "\n -n Number output lines"
48 //usage: "\n -b Number nonempty lines"
50 //usage: IF_FEATURE_CATV(
51 //usage: "\n -v Show nonprinting characters as ^x or M-x"
52 //usage: "\n -t ...and tabs as ^I"
53 //usage: "\n -e ...and end lines with $"
54 //usage: "\n -A Same as -vte"
57 Longopts not implemented yet:
58 --number-nonblank number nonempty output lines, overrides -n
59 --number number all output lines
60 --show-nonprinting use ^ and M- notation, except for LFD and TAB
61 --show-all equivalent to -vet
63 -E, --show-ends display $ at end of each line (-e sans -v)
64 -T, --show-tabs display TAB characters as ^I (-t sans -v)
65 -s, --squeeze-blank suppress repeated empty output lines
68 //usage:#define cat_example_usage
69 //usage: "$ cat /proc/uptime\n"
70 //usage: "110716.72 17.67"
73 #include "common_bufsiz.h"
75 #if ENABLE_FEATURE_CATV
77 * cat -v implementation for busybox
79 * Copyright (C) 2006 Rob Landley <rob@landley.net>
81 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
83 /* Rob had "cat -v" implemented as a separate applet, catv.
84 * See "cat -v considered harmful" at
85 * http://cm.bell-labs.com/cm/cs/doc/84/kp.ps.gz
86 * From USENIX Summer Conference Proceedings, 1983
88 * The talk reviews reasons for UNIX's popularity and shows, using UCB cat
89 * as a primary example, how UNIX has grown fat. cat isn't for printing
90 * files with line numbers, it isn't for compressing multiple blank lines,
91 * it's not for looking at non-printing ASCII characters, it's for
92 * concatenating files.
93 * We are reminded that ls isn't the place for code to break a single column
94 * into multiple ones, and that mailnews shouldn't have its own more
95 * processing or joke encryption code.
98 * I agree with the argument. Unfortunately, this ship has sailed (1983...).
99 * There are dozens of Linux distros and each of them has "cat" which supports -v.
100 * It's unrealistic for us to "reeducate" them to use our, incompatible way
101 * to achieve "cat -v" effect. The actual effect would be "users pissed off
102 * by gratuitous incompatibility".
104 #define CAT_OPT_e (1<<0)
105 #define CAT_OPT_t (1<<1)
106 #define CAT_OPT_v (1<<2)
107 /* -A occupies bit (1<<3) */
108 #define CAT_OPT_n ((1<<4) * ENABLE_FEATURE_CATN)
109 #define CAT_OPT_b ((1<<5) * ENABLE_FEATURE_CATN)
110 static int catv(unsigned opts, char **argv)
112 int retval = EXIT_SUCCESS;
114 #if ENABLE_FEATURE_CATN
115 bool eol_seen = (opts & (CAT_OPT_n|CAT_OPT_b));
116 unsigned eol_char = (eol_seen ? '\n' : 0x100);
117 unsigned skip_num_on = (opts & CAT_OPT_b) ? '\n' : 0x100;
121 BUILD_BUG_ON(CAT_OPT_e != VISIBLE_ENDLINE);
122 BUILD_BUG_ON(CAT_OPT_t != VISIBLE_SHOW_TABS);
123 #if 0 /* These consts match, we can just pass "opts" to visible() */
124 if (opts & CAT_OPT_e)
125 flags |= VISIBLE_ENDLINE;
126 if (opts & CAT_OPT_t)
127 flags |= VISIBLE_SHOW_TABS;
130 #define read_buf bb_common_bufsiz1
131 setup_common_bufsiz();
133 fd = open_or_warn_stdin(*argv);
135 retval = EXIT_FAILURE;
141 res = read(fd, read_buf, COMMON_BUFSIZE);
143 retval = EXIT_FAILURE;
146 for (i = 0; i < res; i++) {
147 unsigned char c = read_buf[i];
148 char buf[sizeof("M-^c")];
149 #if ENABLE_FEATURE_CATN
150 if (eol_seen && c != skip_num_on)
151 printf("%6u ", ++lineno);
152 eol_seen = (c == eol_char);
154 visible(c, buf, opts);
158 if (ENABLE_FEATURE_CLEAN_UP && fd)
162 fflush_stdout_and_exit(retval);
168 int cat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
169 int cat_main(int argc UNUSED_PARAM, char **argv)
171 #if ENABLE_FEATURE_CATV || ENABLE_FEATURE_CATN
176 getopt32(argv, IF_FEATURE_CATV("^")
177 /* -u is ignored ("unbuffered") */
178 IF_FEATURE_CATV("etvA")IF_FEATURE_CATN("nb")"u"
179 IF_FEATURE_CATV("\0" "Aetv" /* -A == -vet */)
183 /* Read from stdin if there's nothing else to do. */
185 *--argv = (char*)"-";
187 #if ENABLE_FEATURE_CATV
189 return catv(opts, argv);
193 #if ENABLE_FEATURE_CATN
194 # define CAT_OPT_n (1<<0)
195 # define CAT_OPT_b (1<<1)
196 if (opts & (CAT_OPT_n|CAT_OPT_b)) { /* -n or -b */
197 struct number_state ns;
204 ns.all = !(opts & CAT_OPT_b); /* -n without -b */
205 ns.nonempty = (opts & CAT_OPT_b); /* -b (with or without -n) */
207 print_numbered_lines(&ns, *argv);
209 fflush_stdout_and_exit(EXIT_SUCCESS);