71 lines
1.7 KiB
C
71 lines
1.7 KiB
C
/*
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* Copyright (c) 2020 Dylan Lom <djl@dylanlom.com>
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
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* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
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* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
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* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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* PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <errno.h>
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include "util.h"
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const char *argv0;
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void
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usage()
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{
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fprintf(stderr, "usage: %s ln\n", argv0);
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exit(EXIT_FAILURE);
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}
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int
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main(int argc, char *argv[])
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{
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SET_ARGV0();
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if (argc < 1) usage();
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int ln;
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char *p;
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ln = (int)strtol(argv[0], &p, 10);
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if (errno != 0 || *p != '\0') {
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fprintf(stderr, "strtol: %s\n", errno
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? strerror(errno)
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: "Failed to parse ln argument."
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);
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exit(EXIT_FAILURE);
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}
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SHIFT_ARGS();
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int cln = 1;
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while (cln <= ln) {
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char c;
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int r;
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r = read(STDIN_FILENO, &c, 1);
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if (r == -1) {
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fprintf(stderr, "read: %s\n", strerror(errno));
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exit(1);
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} else if (r == 0) {
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exit(2);
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} else if (cln == ln) {
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putc(c, stdout);
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}
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if (c == '\n') cln++;
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}
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return EXIT_SUCCESS;
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}
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