/* vi: set sw=4 ts=4: *//* * Mini head implementation for busybox * * Copyright (C) 1999 by Lineo, inc. and John Beppu * Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */#include <stdio.h>#include <getopt.h>#include <stdlib.h>#include <string.h>#include <ctype.h>#include "busybox.h"static int head(int len, FILE *fp){	int i;	char *input;	for (i = 0; i < len; i++) {		if ((input = get_line_from_file(fp)) == NULL)			break;		fputs(input, stdout);		free(input);	}	return 0;}/* BusyBoxed head(1) */int head_main(int argc, char **argv){	FILE *fp;	int need_headers, opt, len = 10, status = EXIT_SUCCESS;	if (( argc >= 2 ) && ( argv [1][0] == '-' ) && isdigit ( argv [1][1] )) {		len = atoi ( &argv [1][1] );		optind = 2;	}	/* parse argv[] */	while ((opt = getopt(argc, argv, "n:")) > 0) {		switch (opt) {		case 'n':			len = atoi(optarg);			if (len >= 0)				break;			/* fallthrough */		default:			show_usage();		}	}	/* get rest of argv[] or stdin if nothing's left */	if (argv[optind] == NULL) {		head(len, stdin);		return status;	} 	need_headers = optind != (argc - 1);	while (argv[optind]) {		if (strcmp(argv[optind], "-") == 0) {			fp = stdin;			argv[optind] = "standard input";		} else {			if ((fp = wfopen(argv[optind], "r")) == NULL)				status = EXIT_FAILURE;		}		if (fp) {			if (need_headers) {				printf("==> %s <==\n", argv[optind]);			}			head(len, fp);			if (ferror(fp)) {				perror_msg("%s", argv[optind]);				status = EXIT_FAILURE;			}			if (optind < argc - 1)				putchar('\n');			if (fp != stdin)				fclose(fp);		}		optind++;	}	return status;}