busybox/coreutils/catv.c

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/* 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 source tree.
*/
/* See "Cat -v considered harmful" at
* http://cm.bell-labs.com/cm/cs/doc/84/kp.ps.gz */
//usage:#define catv_trivial_usage
//usage: "[-etv] [FILE]..."
//usage:#define catv_full_usage "\n\n"
//usage: "Display nonprinting characters as ^x or M-x\n"
//usage: "\nOptions:"
//usage: "\n -e End each line with $"
//usage: "\n -t Show tabs as ^I"
//usage: "\n -v Don't use ^x or M-x escapes"
#include "libbb.h"
int catv_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int catv_main(int argc UNUSED_PARAM, char **argv)
{
int retval = EXIT_SUCCESS;
int fd;
unsigned flags;
flags = getopt32(argv, "etv");
#define CATV_OPT_e (1<<0)
#define CATV_OPT_t (1<<1)
#define CATV_OPT_v (1<<2)
flags ^= CATV_OPT_v;
argv += optind;
/* Read from stdin if there's nothing else to do. */
if (!argv[0])
*--argv = (char*)"-";
do {
fd = open_or_warn_stdin(*argv);
if (fd < 0) {
retval = EXIT_FAILURE;
continue;
}
for (;;) {
int i, res;
#define read_buf bb_common_bufsiz1
res = read(fd, read_buf, COMMON_BUFSIZE);
if (res < 0)
retval = EXIT_FAILURE;
if (res < 1)
break;
for (i = 0; i < res; i++) {
unsigned char c = read_buf[i];
if (c > 126 && (flags & CATV_OPT_v)) {
if (c == 127) {
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printf("^?");
continue;
}
printf("M-");
c -= 128;
}
if (c < 32) {
if (c == 10) {
if (flags & CATV_OPT_e)
bb_putchar('$');
} else if (flags & (c==9 ? CATV_OPT_t : CATV_OPT_v)) {
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printf("^%c", c+'@');
continue;
}
}
bb_putchar(c);
}
}
if (ENABLE_FEATURE_CLEAN_UP && fd)
close(fd);
} while (*++argv);
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fflush_stdout_and_exit(retval);
}