75 lines
1.2 KiB
C
75 lines
1.2 KiB
C
/* See LICENSE file for copyright and license details. */
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "text.h"
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#include "util.h"
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static void head(FILE *, const char *, long);
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static void
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usage(void)
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{
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eprintf("usage: %s [-n lines] [file...]\n", argv0);
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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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long n = 10;
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FILE *fp;
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int ret = 0;
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int newline, many;
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ARGBEGIN {
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case 'n':
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n = estrtol(EARGF(usage()), 0);
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break;
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ARGNUM:
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n = ARGNUMF(0);
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break;
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default:
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usage();
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} ARGEND;
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if (argc == 0) {
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head(stdin, "<stdin>", n);
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} else {
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many = argc > 1;
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for (newline = 0; argc > 0; argc--, argv++) {
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if (!(fp = fopen(argv[0], "r"))) {
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weprintf("fopen %s:", argv[0]);
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ret = 1;
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continue;
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}
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if (many)
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printf("%s==> %s <==\n",
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newline ? "\n" : "", argv[0]);
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newline = 1;
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head(fp, argv[0], n);
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fclose(fp);
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}
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}
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return ret;
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}
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static void
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head(FILE *fp, const char *str, long n)
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{
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char *buf = NULL;
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size_t size = 0;
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ssize_t len;
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unsigned long i = 0;
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while (i < n && ((len = getline(&buf, &size, fp)) != -1)) {
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fputs(buf, stdout);
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if (buf[len - 1] == '\n')
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i++;
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}
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free(buf);
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if (ferror(fp))
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eprintf("%s: read error:", str);
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}
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