1 /* vi: set sw=4 ts=4: */
2 /*
3 * cat implementation for busybox
4 *
5 * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
6 *
7 * Licensed under GPLv2, see file LICENSE in this source tree.
8 */
9 //config:config CAT
10 //config: bool "cat (5.6 kb)"
11 //config: default y
12 //config: help
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.
15 //config:
16 //config:config FEATURE_CATN
17 //config: bool "Enable -n and -b options"
18 //config: default y
19 //config: depends on CAT
20 //config: help
21 //config: -n numbers all output lines while -b numbers nonempty output lines.
22 //config:
23 //config:config FEATURE_CATV
24 //config: bool "cat -v[etA]"
25 //config: default y
26 //config: depends on CAT
27 //config: help
28 //config: Display nonprinting characters as escape sequences
29
30 //applet:IF_CAT(APPLET(cat, BB_DIR_BIN, BB_SUID_DROP))
31
32 //kbuild:lib-$(CONFIG_CAT) += cat.o
33
34 /* BB_AUDIT SUSv3 compliant */
35 /* http://www.opengroup.org/onlinepubs/007904975/utilities/cat.html */
36
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]..."
40 //usage:#else
41 //usage:#define cat_trivial_usage
42 //usage: "[FILE]..."
43 //usage:#endif
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"
49 //usage: )
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"
55 //usage: )
56 /*
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
62 Not implemented yet:
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
66 */
67 //usage:
68 //usage:#define cat_example_usage
69 //usage: "$ cat /proc/uptime\n"
70 //usage: "110716.72 17.67"
71
72 #include "libbb.h"
73 #include "common_bufsiz.h"
74
75 #if ENABLE_FEATURE_CATV
76 /*
77 * cat -v implementation for busybox
78 *
79 * Copyright (C) 2006 Rob Landley <rob@landley.net>
80 *
81 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
82 */
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
87 * """
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.
96 * """
97 *
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".
103 */
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)
catv(unsigned opts,char ** argv)110 static int catv(unsigned opts, char **argv)
111 {
112 int retval = EXIT_SUCCESS;
113 int fd;
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;
118 unsigned lineno = 0;
119 #endif
120
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;
128 #endif
129
130 #define read_buf bb_common_bufsiz1
131 setup_common_bufsiz();
132 do {
133 fd = open_or_warn_stdin(*argv);
134 if (fd < 0) {
135 retval = EXIT_FAILURE;
136 continue;
137 }
138 for (;;) {
139 int i, res;
140
141 res = read(fd, read_buf, COMMON_BUFSIZE);
142 if (res < 0)
143 retval = EXIT_FAILURE;
144 if (res <= 0)
145 break;
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);
153 #endif
154 visible(c, buf, opts);
155 fputs_stdout(buf);
156 }
157 }
158 if (ENABLE_FEATURE_CLEAN_UP && fd)
159 close(fd);
160 } while (*++argv);
161
162 fflush_stdout_and_exit(retval);
163 }
164 #undef CAT_OPT_n
165 #undef CAT_OPT_b
166 #endif
167
168 int cat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
cat_main(int argc UNUSED_PARAM,char ** argv)169 int cat_main(int argc UNUSED_PARAM, char **argv)
170 {
171 #if ENABLE_FEATURE_CATV || ENABLE_FEATURE_CATN
172 unsigned opts;
173
174 opts =
175 #endif
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 */)
180 );
181 argv += optind;
182
183 /* Read from stdin if there's nothing else to do. */
184 if (!argv[0])
185 *--argv = (char*)"-";
186
187 #if ENABLE_FEATURE_CATV
188 if (opts & 7)
189 return catv(opts, argv);
190 opts >>= 4;
191 #endif
192
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;
198 int exitcode;
199
200 ns.width = 6;
201 ns.start = 1;
202 ns.inc = 1;
203 ns.sep = "\t";
204 ns.empty_str = NULL;
205 ns.all = !(opts & CAT_OPT_b); /* -n without -b */
206 ns.nonempty = (opts & CAT_OPT_b); /* -b (with or without -n) */
207 exitcode = EXIT_SUCCESS;
208 do {
209 exitcode |= print_numbered_lines(&ns, *argv);
210 } while (*++argv);
211 fflush_stdout_and_exit(exitcode);
212 }
213 /*opts >>= 2;*/
214 #endif
215
216 return bb_cat(argv);
217 }
218