busybox/coreutils/wc.c

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/* vi: set sw=4 ts=4: */
/*
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* wc implementation for busybox
*
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* Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
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/* 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:
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* 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 &&
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* (dd ibs=1k skip=1 count=0 &> /dev/null; wc -c) < /tmp/testfile
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*
* for which 'wc -c' should output '0'.
*/
//config:config WC
//config: bool "wc (4.5 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-$(CONFIG_WC) += wc.o
/* BB_AUDIT SUSv3 compliant. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/wc.html */
#include "libbb.h"
#include "unicode.h"
#if !ENABLE_LOCALE_SUPPORT
# undef isprint
# undef isspace
# define isprint(c) ((unsigned)((c) - 0x20) <= (0x7e - 0x20))
# define isspace(c) ((c) == ' ')
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#endif
#if ENABLE_FEATURE_WC_LARGE
# define COUNT_T unsigned long long
# define COUNT_FMT "llu"
#else
# define COUNT_T unsigned
# define COUNT_FMT "u"
#endif
/* We support -m even when UNICODE_SUPPORT is off,
* we just don't advertise it in help text,
* since it is the same as -c in this case.
*/
//usage:#define wc_trivial_usage
//usage: "[-c"IF_UNICODE_SUPPORT("m")"lwL] [FILE]..."
//usage:
//usage:#define wc_full_usage "\n\n"
//usage: "Count lines, words, and bytes for each FILE (or stdin)\n"
//usage: "\n -c Count bytes"
//usage: IF_UNICODE_SUPPORT(
//usage: "\n -m Count characters"
//usage: )
//usage: "\n -l Count newlines"
//usage: "\n -w Count words"
//usage: "\n -L Print longest line length"
//usage:
//usage:#define wc_example_usage
//usage: "$ 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:
*/
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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;
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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;
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smallint status = EXIT_SUCCESS;
unsigned print_type;
init_unicode();
print_type = getopt32(argv, "lwmcL");
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if (print_type == 0) {
print_type = (1 << WC_LINES) | (1 << WC_WORDS) | (1 << WC_BYTES);
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}
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argv += optind;
if (!argv[0]) {
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*--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;
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}
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memset(totals, 0, sizeof(totals));
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pcounts = counts;
num_files = 0;
while ((arg = *argv++) != NULL) {
FILE *fp;
const char *s;
unsigned u;
unsigned linepos;
smallint in_word;
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++num_files;
fp = fopen_or_warn_stdin(arg);
if (!fp) {
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status = EXIT_FAILURE;
continue;
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}
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memset(counts, 0, sizeof(counts));
linepos = 0;
in_word = 0;
while (1) {
int c;
/* Our -w doesn't match GNU wc exactly... oh well */
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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 */
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++linepos;
if (!isspace(c)) {
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in_word = 1;
continue;
}
} else if ((unsigned)(c - 9) <= 4) {
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/* \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:
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if (linepos > counts[WC_LENGTH]) {
counts[WC_LENGTH] = linepos;
}
if (c == '\n') {
++counts[WC_LINES];
}
if (c != '\v') {
linepos = 0;
}
}
} else {
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continue;
}
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counts[WC_WORDS] += in_word;
in_word = 0;
if (c == EOF) {
break;
}
}
fclose_if_not_stdin(fp);
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if (totals[WC_LENGTH] < counts[WC_LENGTH]) {
totals[WC_LENGTH] = counts[WC_LENGTH];
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}
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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;
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u = 0;
do {
if (print_type & (1 << u)) {
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printf(s, pcounts[u]);
s = " %9"COUNT_FMT; /* Ok... restore the leading space. */
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}
totals[u] += pcounts[u];
} while (++u < NUM_WCS);
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printf(fname_fmt, arg);
}
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/* 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";
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pcounts = totals;
--argv;
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goto OUTPUT;
}
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fflush_stdout_and_exit(status);
}