source: MondoRescue/branches/stable/mindi-busybox/coreutils/wc.c@ 821

/* vi: set sw=4 ts=4: */
/*
 * wc implementation for busybox
 *
 * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

/* BB_AUDIT SUSv3 _NOT_ compliant -- option -m is not currently supported. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/wc.html */

/* 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.
 *
 * TODO:
 *
 * When locale support is enabled, count multibyte chars in the '-m' case.
 *
 * 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'.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "busybox.h"

#ifdef CONFIG_LOCALE_SUPPORT
#include <locale.h>
#include <ctype.h>
#define isspace_given_isprint(c) isspace(c)
#else
#undef isspace
#undef isprint
#define isspace(c) ((((c) == ' ') || (((unsigned int)((c) - 9)) <= (13 - 9))))
#define isprint(c) (((unsigned int)((c) - 0x20)) <= (0x7e - 0x20))
#define isspace_given_isprint(c) ((c) == ' ')
#endif

enum {
    WC_LINES    = 0,
    WC_WORDS    = 1,
    WC_CHARS    = 2,
    WC_LENGTH   = 3
};

/* Note: If this changes, remember to change the initialization of
 *       'name' in wc_main.  It needs to point to the terminating nul. */
static const char wc_opts[] = "lwcL";   /* READ THE WARNING ABOVE! */

enum {
    OP_INC_LINE = 1, /* OP_INC_LINE must be 1. */
    OP_SPACE    = 2,
    OP_NEWLINE  = 4,
    OP_TAB      = 8,
    OP_NUL      = 16,
};

/* Note: If fmt_str changes, the offsets to 's' in the OUTPUT section
 *       will need to be updated. */
static const char fmt_str[] = " %7u\0 %s\n";
static const char total_str[] = "total";

int wc_main(int argc, char **argv)
{
    FILE *fp;
    const char *s;
    unsigned int *pcounts;
    unsigned int counts[4];
    unsigned int totals[4];
    unsigned int linepos;
    unsigned int u;
    int num_files = 0;
    int c;
    char status = EXIT_SUCCESS;
    char in_word;
    char print_type;

    print_type = bb_getopt_ulflags(argc, argv, wc_opts);

    if (print_type == 0) {
        print_type = (1 << WC_LINES) | (1 << WC_WORDS) | (1 << WC_CHARS);
    }

    argv += optind;
    if (!*argv) {
        *--argv = (char *) bb_msg_standard_input;
    }

    memset(totals, 0, sizeof(totals));

    pcounts = counts;

    do {
        ++num_files;
        if (!(fp = bb_wfopen_input(*argv))) {
            status = EXIT_FAILURE;
            continue;
        }

        memset(counts, 0, sizeof(counts));
        linepos = 0;
        in_word = 0;

        do {
            ++counts[WC_CHARS];
            c = getc(fp);
            if (isprint(c)) {
                ++linepos;
                if (!isspace_given_isprint(c)) {
                    in_word = 1;
                    continue;
                }
            } else if (((unsigned int)(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 if (c == EOF) {
                if (ferror(fp)) {
                    bb_perror_msg("%s", *argv);
                    status = EXIT_FAILURE;
                }
                --counts[WC_CHARS];
                goto DO_EOF;        /* Treat an EOF as '\r'. */
            } else {
                continue;
            }

            counts[WC_WORDS] += in_word;
            in_word = 0;
            if (c == EOF) {
                break;
            }
        } while (1);

        if (totals[WC_LENGTH] < counts[WC_LENGTH]) {
            totals[WC_LENGTH] = counts[WC_LENGTH];
        }
        totals[WC_LENGTH] -= counts[WC_LENGTH];

        bb_fclose_nonstdin(fp);

    OUTPUT:
        s = fmt_str + 1;            /* Skip the leading space on 1st pass. */
        u = 0;
        do {
            if (print_type & (1 << u)) {
                bb_printf(s, pcounts[u]);
                s = fmt_str;        /* Ok... restore the leading space. */
            }
            totals[u] += pcounts[u];
        } while (++u < 4);

        s += 8;                     /* Set the format to the empty string. */

        if (*argv != bb_msg_standard_input) {
            s -= 3;                 /* We have a name, so do %s conversion. */
        }
        bb_printf(s, *argv);

    } while (*++argv);

    /* 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. */
        *--argv = (char *) total_str;
        pcounts = totals;
        goto OUTPUT;
    }

    bb_fflush_stdout_and_exit(status);
}