/* vi: set sw=4 ts=4: */ /* * cat implementation for busybox * * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org> * * Licensed under GPLv2, see file LICENSE in this source tree. */ //config:config CAT //config: bool "cat (5.6 kb)" //config: default y //config: help //config: cat is used to concatenate files and print them to the standard //config: output. Enable this option if you wish to enable the 'cat' utility. //config: //config:config FEATURE_CATN //config: bool "Enable -n and -b options" //config: default y //config: depends on CAT //config: help //config: -n numbers all output lines while -b numbers nonempty output lines. //config: //config:config FEATURE_CATV //config: bool "cat -v[etA]" //config: default y //config: depends on CAT //config: help //config: Display nonprinting characters as escape sequences //applet:IF_CAT(APPLET(cat, BB_DIR_BIN, BB_SUID_DROP)) //kbuild:lib-$(CONFIG_CAT) += cat.o /* BB_AUDIT SUSv3 compliant */ /* http://www.opengroup.org/onlinepubs/007904975/utilities/cat.html */ //usage:#if ENABLE_FEATURE_CATN || ENABLE_FEATURE_CATV //usage:#define cat_trivial_usage //usage: "[-" IF_FEATURE_CATN("nb") IF_FEATURE_CATV("vteA") "] [FILE]..." //usage:#else //usage:#define cat_trivial_usage //usage: "[FILE]..." //usage:#endif //usage:#define cat_full_usage "\n\n" //usage: "Print FILEs to stdout\n" //usage: IF_FEATURE_CATN( //usage: "\n -n Number output lines" //usage: "\n -b Number nonempty lines" //usage: ) //usage: IF_FEATURE_CATV( //usage: "\n -v Show nonprinting characters as ^x or M-x" //usage: "\n -t ...and tabs as ^I" //usage: "\n -e ...and end lines with $" //usage: "\n -A Same as -vte" //usage: ) /* Longopts not implemented yet: --number-nonblank number nonempty output lines, overrides -n --number number all output lines --show-nonprinting use ^ and M- notation, except for LFD and TAB --show-all equivalent to -vet Not implemented yet: -E, --show-ends display $ at end of each line (-e sans -v) -T, --show-tabs display TAB characters as ^I (-t sans -v) -s, --squeeze-blank suppress repeated empty output lines */ //usage: //usage:#define cat_example_usage //usage: "$ cat /proc/uptime\n" //usage: "110716.72 17.67" #include "libbb.h" #include "common_bufsiz.h" #if ENABLE_FEATURE_CATV /* * cat -v implementation for busybox * * Copyright (C) 2006 Rob Landley <rob@landley.net> * * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ /* Rob had "cat -v" implemented as a separate applet, catv. * See "cat -v considered harmful" at * http://cm.bell-labs.com/cm/cs/doc/84/kp.ps.gz * From USENIX Summer Conference Proceedings, 1983 * """ * The talk reviews reasons for UNIX's popularity and shows, using UCB cat * as a primary example, how UNIX has grown fat. cat isn't for printing * files with line numbers, it isn't for compressing multiple blank lines, * it's not for looking at non-printing ASCII characters, it's for * concatenating files. * We are reminded that ls isn't the place for code to break a single column * into multiple ones, and that mailnews shouldn't have its own more * processing or joke encryption code. * """ * * I agree with the argument. Unfortunately, this ship has sailed (1983...). * There are dozens of Linux distros and each of them has "cat" which supports -v. * It's unrealistic for us to "reeducate" them to use our, incompatible way * to achieve "cat -v" effect. The actual effect would be "users pissed off * by gratuitous incompatibility". */ #define CAT_OPT_e (1<<0) #define CAT_OPT_t (1<<1) #define CAT_OPT_v (1<<2) /* -A occupies bit (1<<3) */ #define CAT_OPT_n ((1<<4) * ENABLE_FEATURE_CATN) #define CAT_OPT_b ((1<<5) * ENABLE_FEATURE_CATN) static int catv(unsigned opts, char **argv) { int retval = EXIT_SUCCESS; int fd; #if ENABLE_FEATURE_CATN bool eol_seen = (opts & (CAT_OPT_n|CAT_OPT_b)); unsigned eol_char = (eol_seen ? '\n' : 0x100); unsigned skip_num_on = (opts & CAT_OPT_b) ? '\n' : 0x100; unsigned lineno = 0; #endif BUILD_BUG_ON(CAT_OPT_e != VISIBLE_ENDLINE); BUILD_BUG_ON(CAT_OPT_t != VISIBLE_SHOW_TABS); #if 0 /* These consts match, we can just pass "opts" to visible() */ if (opts & CAT_OPT_e) flags |= VISIBLE_ENDLINE; if (opts & CAT_OPT_t) flags |= VISIBLE_SHOW_TABS; #endif #define read_buf bb_common_bufsiz1 setup_common_bufsiz(); do { fd = open_or_warn_stdin(*argv); if (fd < 0) { retval = EXIT_FAILURE; continue; } for (;;) { int i, res; res = read(fd, read_buf, COMMON_BUFSIZE); if (res < 0) retval = EXIT_FAILURE; if (res <= 0) break; for (i = 0; i < res; i++) { unsigned char c = read_buf[i]; char buf[sizeof("M-^c")]; #if ENABLE_FEATURE_CATN if (eol_seen && c != skip_num_on) printf("%6u ", ++lineno); eol_seen = (c == eol_char); #endif visible(c, buf, opts); fputs(buf, stdout); } } if (ENABLE_FEATURE_CLEAN_UP && fd) close(fd); } while (*++argv); fflush_stdout_and_exit(retval); } #undef CAT_OPT_n #undef CAT_OPT_b #endif int cat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int cat_main(int argc UNUSED_PARAM, char **argv) { #if ENABLE_FEATURE_CATV || ENABLE_FEATURE_CATN unsigned opts; opts = #endif getopt32(argv, IF_FEATURE_CATV("^") /* -u is ignored ("unbuffered") */ IF_FEATURE_CATV("etvA")IF_FEATURE_CATN("nb")"u" IF_FEATURE_CATV("\0" "Aetv" /* -A == -vet */) ); argv += optind; /* Read from stdin if there's nothing else to do. */ if (!argv[0]) *--argv = (char*)"-"; #if ENABLE_FEATURE_CATV if (opts & 7) return catv(opts, argv); opts >>= 4; #endif #if ENABLE_FEATURE_CATN # define CAT_OPT_n (1<<0) # define CAT_OPT_b (1<<1) if (opts & (CAT_OPT_n|CAT_OPT_b)) { /* -n or -b */ struct number_state ns; ns.width = 6; ns.start = 1; ns.inc = 1; ns.sep = "\t"; ns.empty_str = "\n"; ns.all = !(opts & CAT_OPT_b); /* -n without -b */ ns.nonempty = (opts & CAT_OPT_b); /* -b (with or without -n) */ do { print_numbered_lines(&ns, *argv); } while (*++argv); fflush_stdout_and_exit(EXIT_SUCCESS); } /*opts >>= 2;*/ #endif return bb_cat(argv); }