busybox/coreutils/uniq.c

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/* vi: set sw=4 ts=4: */
/*
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* uniq implementation for busybox
*
* Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org>
*
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*/
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/* BB_AUDIT SUSv3 compliant */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/uniq.html */
#include "busybox.h"
static const char uniq_opts[] = "f:s:" "cdu\0\1\2\4";
static FILE *xgetoptfile_uniq_s(char **argv, int read0write2)
{
const char *n;
if ((n = *argv) != NULL) {
if ((*n != '-') || n[1]) {
return xfopen(n, "r\0w" + read0write2);
}
}
return (read0write2) ? stdout : stdin;
}
int uniq_main(int argc, char **argv)
{
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FILE *in, *out;
unsigned long dups, skip_fields, skip_chars, i, uniq_flags;
const char *s0, *e0, *s1, *e1, *input_filename;
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int opt;
uniq_flags = skip_fields = skip_chars = 0;
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while ((opt = getopt(argc, argv, uniq_opts)) > 0) {
if ((opt == 'f') || (opt == 's')) {
int t = bb_xgetularg10(optarg);
if (opt == 'f') {
skip_fields = t;
} else {
skip_chars = t;
}
} else if ((s0 = strchr(uniq_opts, opt)) != NULL) {
uniq_flags |= s0[4];
} else {
bb_show_usage();
}
}
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input_filename = *(argv += optind);
in = xgetoptfile_uniq_s(argv, 0);
if (*argv) {
++argv;
}
out = xgetoptfile_uniq_s(argv, 2);
if (*argv && argv[1]) {
bb_show_usage();
}
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s1 = e1 = NULL; /* prime the pump */
do {
s0 = s1;
e0 = e1;
dups = 0;
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/* gnu uniq ignores newlines */
while ((s1 = bb_get_chomped_line_from_file(in)) != NULL) {
e1 = s1;
for (i=skip_fields ; i ; i--) {
e1 = skip_whitespace(e1);
while (*e1 && !isspace(*e1)) {
++e1;
}
}
for (i = skip_chars ; *e1 && i ; i--) {
++e1;
}
if (!s0 || strcmp(e0, e1)) {
break;
}
++dups; /* Note: Testing for overflow seems excessive. */
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}
if (s0) {
if (!(uniq_flags & (2 << !!dups))) {
bb_fprintf(out, "\0%d " + (uniq_flags & 1), dups + 1);
bb_fprintf(out, "%s\n", s0);
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}
free((void *)s0);
}
} while (s1);
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xferror(in, input_filename);
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bb_fflush_stdout_and_exit(EXIT_SUCCESS);
}