busybox/coreutils/head.c
Rob Landley d921b2ecc0 Remove bb_ prefixes from xfuncs.c (and a few other places), consolidate
things like xasprintf() into xfuncs.c, remove xprint_file_by_name() (it only
had one user), clean up lots of #includes...  General cleanup pass.  What I've
been doing for the last couple days.

And it conflicts!  I've removed httpd.c from this checkin due to somebody else
touching that file.  It builds for me.  I have to catch a bus.  (Now you know
why I'm looking forward to Mercurial.)
2006-08-03 15:41:12 +00:00

142 lines
2.9 KiB
C

/* vi: set sw=4 ts=4: */
/*
* head implementation for busybox
*
* Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
/* BB_AUDIT SUSv3 compliant */
/* BB_AUDIT GNU compatible -c, -q, and -v options in 'fancy' configuration. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/head.html */
#include "busybox.h"
static const char head_opts[] =
"n:"
#if ENABLE_FEATURE_FANCY_HEAD
"c:qv"
#endif
;
#if ENABLE_FEATURE_FANCY_HEAD
static const struct suffix_mult head_suffixes[] = {
{ "b", 512 },
{ "k", 1024 },
{ "m", 1024*1024 },
{ NULL, 0 }
};
#endif
static const char header_fmt_str[] = "\n==> %s <==\n";
int head_main(int argc, char **argv)
{
unsigned long count = 10;
unsigned long i;
#if ENABLE_FEATURE_FANCY_HEAD
int count_bytes = 0;
int header_threshhold = 1;
#endif
FILE *fp;
const char *fmt;
char *p;
int opt;
int c;
int retval = EXIT_SUCCESS;
#if !ENABLE_DEBUG_YANK_SUSv2 || ENABLE_FEATURE_FANCY_HEAD
/* Allow legacy syntax of an initial numeric option without -n. */
if ((argc > 1) && (argv[1][0] == '-')
/* && (isdigit)(argv[1][1]) */
&& (((unsigned int)(argv[1][1] - '0')) <= 9)
) {
--argc;
++argv;
p = (*argv) + 1;
goto GET_COUNT;
}
#endif
/* No size benefit in converting this to bb_getopt_ulflags */
while ((opt = getopt(argc, argv, head_opts)) > 0) {
switch(opt) {
#if ENABLE_FEATURE_FANCY_HEAD
case 'q':
header_threshhold = INT_MAX;
break;
case 'v':
header_threshhold = -1;
break;
case 'c':
count_bytes = 1;
/* fall through */
#endif
case 'n':
p = optarg;
#if !ENABLE_DEBUG_YANK_SUSv2 || ENABLE_FEATURE_FANCY_HEAD
GET_COUNT:
#endif
#if !ENABLE_FEATURE_FANCY_HEAD
count = bb_xgetularg10(p);
#else
count = bb_xgetularg_bnd_sfx(p, 10,
0, ULONG_MAX,
head_suffixes);
#endif
break;
default:
bb_show_usage();
}
}
argv += optind;
if (!*argv) {
*--argv = "-";
}
fmt = header_fmt_str + 1;
#if ENABLE_FEATURE_FANCY_HEAD
if (argc - optind <= header_threshhold) {
header_threshhold = 0;
}
#else
if (argc <= optind + 1) {
fmt += 11;
}
/* Now define some things here to avoid #ifdefs in the code below.
* These should optimize out of the if conditions below. */
#define header_threshhold 1
#define count_bytes 0
#endif
do {
if ((fp = bb_wfopen_input(*argv)) != NULL) {
if (fp == stdin) {
*argv = (char *) bb_msg_standard_input;
}
if (header_threshhold) {
bb_printf(fmt, *argv);
}
i = count;
while (i && ((c = getc(fp)) != EOF)) {
if (count_bytes || (c == '\n')) {
--i;
}
putchar(c);
}
if (bb_fclose_nonstdin(fp)) {
bb_perror_msg("%s", *argv); /* Avoid multibyte problems. */
retval = EXIT_FAILURE;
}
xferror_stdout();
}
fmt = header_fmt_str;
} while (*++argv);
bb_fflush_stdout_and_exit(retval);
}