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	head.c - sbase - suckless unix tools
	git clone git://git.suckless.org/sbase
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	---
	head.c (1383B)
	---
	1 /* See LICENSE file for copyright and license details. */
	2 #include <stdint.h>
	3 #include <stdio.h>
	4 #include <stdlib.h>
	5 #include <string.h>
	6
	7 #include "util.h"
	8
	9 static void
	10 head(FILE fp, const char fname, size_t n)
	11 {
	12 char *buf = NULL;
	13 size_t i = 0, size = 0;
	14 ssize_t len;
	15
	16 while (i < n && (len = getline(&buf, &size, fp)) > 0) {
	17 fwrite(buf, 1, len, stdout);
	18 i += (len && (buf[len - 1] == '\n'));
	19 }
	20 free(buf);
	21 if (ferror(fp))
	22 eprintf("getline %s:", fname);
	23 }
	24
	25 static void
	26 usage(void)
	27 {
	28 eprintf("usage: %s [-num \| -n num] [file ...]\n", argv0);
	29 }
	30
	31 int
	32 main(int argc, char *argv[])
	33 {
	34 size_t n = 10;
	35 FILE *fp;
	36 int ret = 0, newline = 0, many = 0;
	37
	38 ARGBEGIN {
	39 case 'n':
	40 n = estrtonum(EARGF(usage()), 0, MIN(LLONG_MAX, SIZE_MAX…
	41 break;
	42 ARGNUM:
	43 n = ARGNUMF();
	44 break;
	45 default:
	46 usage();
	47 } ARGEND
	48
	49 if (!argc) {
	50 head(stdin, "<stdin>", n);
	51 } else {
	52 many = argc > 1;
	53 for (newline = 0; *argv; argc--, argv++) {
	54 if (!strcmp(*argv, "-")) {
	55 *argv = "<stdin>";
	56 fp = stdin;
	57 } else if (!(fp = fopen(*argv, "r"))) {
	58 weprintf("fopen %s:", *argv);
	59 ret = 1;
	60 continue;
	61 }
	62 if (many) {
	63 if (newline)
	64 putchar('\n');
	65 printf("==> %s <==\n", *argv);
	66 }
	67 newline = 1;
	68 head(fp, *argv, n);
	69 if (fp != stdin && fshut(fp, *argv))
	70 ret = 1;
	71 }
	72 }
	73
	74 ret \|= fshut(stdin, "<stdin>") \| fshut(stdout, "<stdout>");
	75
	76 return ret;
	77 }