source: MondoRescue/branches/2.2.9/mindi-busybox/coreutils/comm.c@ 2859

/* vi: set sw=4 ts=4: */
/*
 * Mini comm implementation for busybox
 *
 * Copyright (C) 2005 by Robert Sullivan <cogito.ergo.cogito@gmail.com>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

#include "libbb.h"

#define COMM_OPT_1 (1 << 0)
#define COMM_OPT_2 (1 << 1)
#define COMM_OPT_3 (1 << 2)

/* writeline outputs the input given, appropriately aligned according to class */
static void writeline(char *line, int class)
{
    int flags = option_mask32;
    if (class == 0) {
        if (flags & COMM_OPT_1)
            return;
    } else if (class == 1) {
        if (flags & COMM_OPT_2)
            return;
        if (!(flags & COMM_OPT_1))
            putchar('\t');
    } else /*if (class == 2)*/ {
        if (flags & COMM_OPT_3)
            return;
        if (!(flags & COMM_OPT_1))
            putchar('\t');
        if (!(flags & COMM_OPT_2))
            putchar('\t');
    }
    puts(line);
}

int comm_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int comm_main(int argc UNUSED_PARAM, char **argv)
{
    char *thisline[2];
    FILE *stream[2];
    int i;
    int order;

    opt_complementary = "=2";
    getopt32(argv, "123");
    argv += optind;

    for (i = 0; i < 2; ++i) {
        stream[i] = xfopen_stdin(argv[i]);
    }

    order = 0;
    thisline[1] = thisline[0] = NULL;
    while (1) {
        if (order <= 0) {
            free(thisline[0]);
            thisline[0] = xmalloc_fgetline(stream[0]);
        }
        if (order >= 0) {
            free(thisline[1]);
            thisline[1] = xmalloc_fgetline(stream[1]);
        }

        i = !thisline[0] + (!thisline[1] << 1);
        if (i)
            break;
        order = strcmp(thisline[0], thisline[1]);

        if (order >= 0)
            writeline(thisline[1], order ? 1 : 2);
        else
            writeline(thisline[0], 0);
    }

    /* EOF at least on one of the streams */
    i &= 1;
    if (thisline[i]) {
        /* stream[i] is not at EOF yet */
        /* we did not print thisline[i] yet */
        char *p = thisline[i];
        writeline(p, i);
        while (1) {
            free(p);
            p = xmalloc_fgetline(stream[i]);
            if (!p)
                break;
            writeline(p, i);
        }
    }

    if (ENABLE_FEATURE_CLEAN_UP) {
        fclose(stream[0]);
        fclose(stream[1]);
    }

    return EXIT_SUCCESS;
}