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/*
* UNG's Not GNU
*
* Copyright (c) 2011-2019, Jakob Kaivo <jkk@ung.org>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#define _POSIX_C_SOURCE 2
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
static int head(const char *path, int nlines)
{
FILE *f = stdin;
if (path && strcmp(path, "-")) {
f = fopen(path, "rb");
}
if (f == NULL) {
fprintf(stderr, "head: %s: %s\n", path, strerror(errno));
return 1;
}
int c;
while ((c = fgetc(f)) != EOF && nlines > 0) {
putchar(c);
if (c == '\n') {
nlines--;
}
}
if (f != stdin) {
fclose(f);
}
return 0;
}
int main(int argc, char **argv)
{
int lines = 10;
int showname = 0;
char *end;
int c;
while ((c = getopt(argc, argv, "n:")) != -1) {
switch (c) {
case 'n':
lines = strtol(optarg, &end, 10);
if (*end != '\0') {
fprintf(stderr, "head: invalid number %s\n", optarg);
return 1;
}
break;
default:
return 1;
}
}
if (optind < argc - 1) {
showname = 1;
}
int r = 0;
do {
if (showname) {
if (showname == 1) {
showname++;
} else {
putchar('\n');
}
printf("==> %s <==\n", argv[optind]);
}
r |= head(argv[optind++], lines);
} while (optind < argc);
return r;
}
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