source: MondoRescue/trunk/mindi-busybox/coreutils/uniq.c@ 929

/* vi: set sw=4 ts=4: */
/*
 * uniq implementation for busybox
 *
 * Copyright (C) 2005  Manuel Novoa III  <mjn3@codepoet.org>
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

/* BB_AUDIT SUSv3 compliant */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/uniq.html */

#include "busybox.h"
#include <string.h>
#include <ctype.h>
#include <unistd.h>

static const char uniq_opts[] = "f:s:" "cdu\0\1\2\4";

static FILE *xgetoptfile_uniq_s(char **argv, int read0write2)
{
    const char *n;

    if ((n = *argv) != NULL) {
        if ((*n != '-') || n[1]) {
            return bb_xfopen(n, "r\0w" + read0write2);
        }
    }
    return (read0write2) ? stdout : stdin;
}

int uniq_main(int argc, char **argv)
{
    FILE *in, *out;
    unsigned long dups, skip_fields, skip_chars, i, uniq_flags;
    const char *s0, *e0, *s1, *e1, *input_filename;
    int opt;

    uniq_flags = skip_fields = skip_chars = 0;

    while ((opt = getopt(argc, argv, uniq_opts)) > 0) {
        if ((opt == 'f') || (opt == 's')) {
            int t = bb_xgetularg10(optarg);
            if (opt == 'f') {
                skip_fields = t;
            } else {
                skip_chars = t;
            }
        } else if ((s0 = strchr(uniq_opts, opt)) != NULL) {
            uniq_flags |= s0[4];
        } else {
            bb_show_usage();
        }
    }

    input_filename = *(argv += optind);

    in = xgetoptfile_uniq_s(argv, 0);
    if (*argv) {
        ++argv;
    }
    out = xgetoptfile_uniq_s(argv, 2);
    if (*argv && argv[1]) {
        bb_show_usage();
    }

    s1 = e1 = NULL;             /* prime the pump */

    do {
        s0 = s1;
        e0 = e1;
        dups = 0;

        /* gnu uniq ignores newlines */
        while ((s1 = bb_get_chomped_line_from_file(in)) != NULL) {
            e1 = s1;
            for (i=skip_fields ; i ; i--) {
                e1 = skip_whitespace(e1);
                while (*e1 && !isspace(*e1)) {
                    ++e1;
                }
            }
            for (i = skip_chars ; *e1 && i ; i--) {
                ++e1;
            }

            if (!s0 || strcmp(e0, e1)) {
                break;
            }

            ++dups;      /* Note: Testing for overflow seems excessive. */
        }

        if (s0) {
            if (!(uniq_flags & (2 << !!dups))) {
                bb_fprintf(out, "\0%d " + (uniq_flags & 1), dups + 1);
                bb_fprintf(out, "%s\n", s0);
            }
            free((void *)s0);
        }
    } while (s1);

    bb_xferror(in, input_filename);

    bb_fflush_stdout_and_exit(EXIT_SUCCESS);
}