source: MondoRescue/branches/2.2.5/mindi-busybox/coreutils/catv.c@ 1765

/* vi: set sw=4 ts=4: */
/*
 * cat -v implementation for busybox
 *
 * Copyright (C) 2006 Rob Landley <rob@landley.net>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

/* See "Cat -v considered harmful" at
 * http://cm.bell-labs.com/cm/cs/doc/84/kp.ps.gz */

#include "libbb.h"

int catv_main(int argc, char **argv);
int catv_main(int argc, char **argv)
{
    int retval = EXIT_SUCCESS;
    int fd;
    unsigned flags;

    flags = getopt32(argv, "etv");
#define CATV_OPT_e (1<<0)
#define CATV_OPT_t (1<<1)
#define CATV_OPT_v (1<<2)
    flags ^= CATV_OPT_v;
    argv += optind;

    /* Read from stdin if there's nothing else to do. */
    fd = 0;
    if (!argv[0]) {
        argv--;
        goto jump_in;
    }
    do {
        fd = open_or_warn(*argv, O_RDONLY);
        if (fd < 0) {
            retval = EXIT_FAILURE;
            continue;
        }
 jump_in:
        for (;;) {
            int i, res;

#define read_buf bb_common_bufsiz1
            res = read(fd, read_buf, COMMON_BUFSIZE);
            if (res < 0)
                retval = EXIT_FAILURE;
            if (res < 1)
                break;
            for (i = 0; i < res; i++) {
                unsigned char c = read_buf[i];

                if (c > 126 && (flags & CATV_OPT_v)) {
                    if (c == 127) {
                        printf("^?");
                        continue;
                    }
                    printf("M-");
                    c -= 128;
                }
                if (c < 32) {
                    if (c == 10) {
                        if (flags & CATV_OPT_e)
                            putchar('$');
                    } else if (flags & (c==9 ? CATV_OPT_t : CATV_OPT_v)) {
                        printf("^%c", c+'@');
                        continue;
                    }
                }
                putchar(c);
            }
        }
        if (ENABLE_FEATURE_CLEAN_UP && fd)
            close(fd);
    } while (*++argv);

    fflush_stdout_and_exit(retval);
}