xref: /freebsd/contrib/file/src/getline.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*	$NetBSD: getline.c,v 1.2 2014/09/16 17:23:50 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2011 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Christos Zoulas.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include "file.h"
33 #if !HAVE_GETLINE
34 #include <stdlib.h>
35 #include <stdio.h>
36 #include <unistd.h>
37 #include <errno.h>
38 #include <string.h>
39 
40 file_public ssize_t
41 getdelim(char **buf, size_t *bufsiz, int delimiter, FILE *fp)
42 {
43 	char *ptr, *eptr;
44 
45 
46 	if (*buf == NULL || *bufsiz == 0) {
47 		*bufsiz = BUFSIZ;
48 		if ((*buf = malloc(*bufsiz)) == NULL)
49 			return -1;
50 	}
51 
52 	for (ptr = *buf, eptr = *buf + *bufsiz;;) {
53 		int c = fgetc(fp);
54 		if (c == -1) {
55 			if (feof(fp)) {
56 				ssize_t diff = (ssize_t)(ptr - *buf);
57 				if (diff != 0) {
58 					*ptr = '\0';
59 					return diff;
60 				}
61 			}
62 			return -1;
63 		}
64 		*ptr++ = c;
65 		if (c == delimiter) {
66 			*ptr = '\0';
67 			return ptr - *buf;
68 		}
69 		if (ptr + 2 >= eptr) {
70 			char *nbuf;
71 			size_t nbufsiz = *bufsiz * 2;
72 			ssize_t d = ptr - *buf;
73 			if ((nbuf = realloc(*buf, nbufsiz)) == NULL)
74 				return -1;
75 			*buf = nbuf;
76 			*bufsiz = nbufsiz;
77 			eptr = nbuf + nbufsiz;
78 			ptr = nbuf + d;
79 		}
80 	}
81 }
82 
83 file_public ssize_t
84 getline(char **buf, size_t *bufsiz, FILE *fp)
85 {
86 	return getdelim(buf, bufsiz, '\n', fp);
87 }
88 
89 #endif
90 
91 #ifdef TEST
92 int
93 main(int argc, char *argv[])
94 {
95 	char *p = NULL;
96 	ssize_t len;
97 	size_t n = 0;
98 
99 	while ((len = getline(&p, &n, stdin)) != -1)
100 		(void)printf("%" SIZE_T_FORMAT "d %s", len, p);
101 	free(p);
102 	return 0;
103 }
104 #endif
105