wc

busybox-wc.c (6530B)

---

 /* vi: set sw=4 ts=4: */
 /*
  * wc implementation for busybox
  *
  * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
  *
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 /* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
  *
  * Rewritten to fix a number of problems and do some size optimizations.
  * Problems in the previous busybox implementation (besides bloat) included:
  *  1) broken 'wc -c' optimization (read note below)
  *  2) broken handling of '-' args
  *  3) no checking of ferror on EOF returns
  *  4) isprint() wasn't considered when word counting.
  *
  * NOTES:
  *
  * The previous busybox wc attempted an optimization using stat for the
  * case of counting chars only.  I omitted that because it was broken.
  * It didn't take into account the possibility of input coming from a
  * pipe, or input from a file with file pointer not at the beginning.
  *
  * To implement such a speed optimization correctly, not only do you
  * need the size, but also the file position.  Note also that the
  * file position may be past the end of file.  Consider the example
  * (adapted from example in gnu wc.c)
  *
  *      echo hello > /tmp/testfile &&
  *      (dd ibs=1k skip=1 count=0 &> /dev/null; wc -c) < /tmp/testfile
  *
  * for which 'wc -c' should output '0'.
  */
 //config:config WC
 //config:	bool "wc (4.7 kb)"
 //config:	default y
 //config:	help
 //config:	wc is used to print the number of bytes, words, and lines,
 //config:	in specified files.
 //config:
 //config:config FEATURE_WC_LARGE
 //config:	bool "Support very large counts"
 //config:	default y
 //config:	depends on WC
 //config:	help
 //config:	Use "unsigned long long" for counter variables.
 
 //applet:IF_WC(APPLET(wc, BB_DIR_USR_BIN, BB_SUID_DROP))
 
 //kbuild:lib-$(CONFIG_WC) += wc.o
 
 /* BB_AUDIT SUSv3 compliant. */
 /* http://www.opengroup.org/onlinepubs/007904975/utilities/wc.html */
 
 #include "libbb.h"
 #include "unicode.h"
 
 #if !ENABLE_LOCALE_SUPPORT
 # undef isprint
 # undef isspace
 # define isprint(c) ((unsigned)((c) - 0x20) <= (0x7e - 0x20))
 # define isspace(c) ((c) == ' ')
 #endif
 
 #if ENABLE_FEATURE_WC_LARGE
 # define COUNT_T unsigned long long
 # define COUNT_FMT "llu"
 #else
 # define COUNT_T unsigned
 # define COUNT_FMT "u"
 #endif
 
 /* We support -m even when UNICODE_SUPPORT is off,
  * we just don't advertise it in help text,
  * since it is the same as -c in this case.
  */
 
 //usage:#define wc_trivial_usage
 //usage:       "[-c"IF_UNICODE_SUPPORT("m")"lwL] [FILE]..."
 //usage:
 //usage:#define wc_full_usage "\n\n"
 //usage:       "Count lines, words, and bytes for FILEs (or stdin)\n"
 //usage:     "\n	-c	Count bytes"
 //usage:	IF_UNICODE_SUPPORT(
 //usage:     "\n	-m	Count characters"
 //usage:	)
 //usage:     "\n	-l	Count newlines"
 //usage:     "\n	-w	Count words"
 //usage:     "\n	-L	Print longest line length"
 //usage:
 //usage:#define wc_example_usage
 //usage:       "$ wc /etc/passwd\n"
 //usage:       "     31      46    1365 /etc/passwd\n"
 
 /* Order is important if we want to be compatible with
  * column order in "wc -cmlwL" output:
  */
 enum {
 	WC_LINES    = 0, /* -l */
 	WC_WORDS    = 1, /* -w */
 	WC_UNICHARS = 2, /* -m */
 	WC_BYTES    = 3, /* -c */
 	WC_LENGTH   = 4, /* -L */
 	NUM_WCS     = 5,
 };
 
 int wc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int wc_main(int argc UNUSED_PARAM, char **argv)
 {
 	const char *arg;
 	const char *start_fmt = " %9"COUNT_FMT + 1;
 	const char *fname_fmt = " %s\n";
 	COUNT_T *pcounts;
 	COUNT_T counts[NUM_WCS];
 	COUNT_T totals[NUM_WCS];
 	int num_files;
 	smallint status = EXIT_SUCCESS;
 	unsigned print_type;
 
 	init_unicode();
 
 	print_type = getopt32(argv, "lwmcL");
 
 	if (print_type == 0) {
 		print_type = (1 << WC_LINES) | (1 << WC_WORDS) | (1 << WC_BYTES);
 	}
 
 	argv += optind;
 	if (!argv[0]) {
 		*--argv = (char *) bb_msg_standard_input;
 		fname_fmt = "\n";
 	}
 	if (!argv[1]) { /* zero or one filename? */
 		if (!((print_type-1) & print_type)) /* exactly one option? */
 			start_fmt = "%"COUNT_FMT;
 	}
 
 	memset(totals, 0, sizeof(totals));
 
 	pcounts = counts;
 
 	num_files = 0;
 	while ((arg = *argv++) != NULL) {
 		FILE *fp;
 		const char *s;
 		unsigned u;
 		unsigned linepos;
 		smallint in_word;
 
 		++num_files;
 		fp = fopen_or_warn_stdin(arg);
 		if (!fp) {
 			status = EXIT_FAILURE;
 			continue;
 		}
 
 		memset(counts, 0, sizeof(counts));
 		linepos = 0;
 		in_word = 0;
 
 		while (1) {
 			int c;
 			/* Our -w doesn't match GNU wc exactly... oh well */
 
 			c = getc(fp);
 			if (c == EOF) {
 				if (ferror(fp)) {
 					bb_simple_perror_msg(arg);
 					status = EXIT_FAILURE;
 				}
 				goto DO_EOF;  /* Treat an EOF as '\r'. */
 			}
 
 			/* Cater for -c and -m */
 			++counts[WC_BYTES];
 			if (unicode_status != UNICODE_ON /* every byte is a new char */
 			 || (c & 0xc0) != 0x80 /* it isn't a 2nd+ byte of a Unicode char */
 			) {
 				++counts[WC_UNICHARS];
 			}
 
 			if (isprint_asciionly(c)) { /* FIXME: not unicode-aware */
 				++linepos;
 				if (!isspace(c)) {
 					in_word = 1;
 					continue;
 				}
 			} else if ((unsigned)(c - 9) <= 4) {
 				/* \t  9
 				 * \n 10
 				 * \v 11
 				 * \f 12
 				 * \r 13
 				 */
 				if (c == '\t') {
 					linepos = (linepos | 7) + 1;
 				} else {  /* '\n', '\r', '\f', or '\v' */
  DO_EOF:
 					if (linepos > counts[WC_LENGTH]) {
 						counts[WC_LENGTH] = linepos;
 					}
 					if (c == '\n') {
 						++counts[WC_LINES];
 					}
 					if (c != '\v') {
 						linepos = 0;
 					}
 				}
 			} else {
 				continue;
 			}
 
 			counts[WC_WORDS] += in_word;
 			in_word = 0;
 			if (c == EOF) {
 				break;
 			}
 		}
 
 		fclose_if_not_stdin(fp);
 
 		if (totals[WC_LENGTH] < counts[WC_LENGTH]) {
 			totals[WC_LENGTH] = counts[WC_LENGTH];
 		}
 		totals[WC_LENGTH] -= counts[WC_LENGTH];
 
  OUTPUT:
 		/* coreutils wc tries hard to print pretty columns
 		 * (saves results for all files, finds max col len etc...)
 		 * we won't try that hard, it will bloat us too much */
 		s = start_fmt;
 		u = 0;
 		do {
 			if (print_type & (1 << u)) {
 				printf(s, pcounts[u]);
 				s = " %9"COUNT_FMT; /* Ok... restore the leading space. */
 			}
 			totals[u] += pcounts[u];
 		} while (++u < NUM_WCS);
 		printf(fname_fmt, arg);
 	}
 
 	/* If more than one file was processed, we want the totals.  To save some
 	 * space, we set the pcounts ptr to the totals array.  This has the side
 	 * effect of trashing the totals array after outputting it, but that's
 	 * irrelavent since we no longer need it. */
 	if (num_files > 1) {
 		num_files = 0;  /* Make sure we don't get here again. */
 		arg = "total";
 		pcounts = totals;
 		--argv;
 		goto OUTPUT;
 	}
 
 	fflush_stdout_and_exit(status);
 }