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