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: "\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 opts;
#define CATV_OPT_e (1<<0)
#define CATV_OPT_t (1<<1)
#define CATV_OPT_v (1<<2)
typedef char BUG_const_mismatch[
CATV_OPT_e == VISIBLE_ENDLINE && CATV_OPT_t == VISIBLE_SHOW_TABS
? 1 : -1
];
opts = getopt32(argv, "etv");
argv += optind;
#if 0 /* These consts match, we can just pass "opts" to visible() */
if (opts & CATV_OPT_e)
flags |= VISIBLE_ENDLINE;
if (opts & CATV_OPT_t)
flags |= VISIBLE_SHOW_TABS;
#endif
/* 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 <= 0)
break;
for (i = 0; i < res; i++) {
unsigned char c = read_buf[i];
if (opts & CATV_OPT_v) {
putchar(c);
} else {
char buf[sizeof("M-^c")];
visible(c, buf, opts);
fputs(buf, stdout);
}
}
}
if (ENABLE_FEATURE_CLEAN_UP && fd)
close(fd);
} while (*++argv);
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fflush_stdout_and_exit(retval);
}