2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 #if defined(LIBC_SCCS) && !defined(lint)
38 static char sccsid[] = "@(#)fgetln.c 8.2 (Berkeley) 1/2/94";
39 #endif /* LIBC_SCCS and not lint */
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
43 #include "namespace.h"
47 #include "un-namespace.h"
48 #include "libc_private.h"
52 * Expand the line buffer. Return -1 on error.
54 * The `new size' does not account for a terminating '\0',
59 slbexpand(FILE *fp, size_t newsize)
66 if (fp->_lb._size >= newsize)
68 if ((p = realloc(fp->_lb._base, newsize)) == NULL)
71 fp->_lb._size = newsize;
76 * Get an input line. The returned pointer often (but not always)
77 * points into a stdio buffer. Fgetln does not alter the text of
78 * the returned line (which is thus not a C string because it will
79 * not necessarily end with '\0'), but does allow callers to modify
80 * it if they wish. Thus, we set __SMOD in case the caller does.
83 fgetln(FILE *fp, size_t *lenp)
90 /* make sure there is input */
91 if (fp->_r <= 0 && __srefill(fp)) {
97 /* look for a newline in the input */
98 if ((p = memchr((void *)fp->_p, '\n', (size_t)fp->_r)) != NULL) {
102 * Found one. Flag buffer as modified to keep fseek from
103 * `optimising' a backward seek, in case the user stomps on
106 p++; /* advance over it */
107 ret = (char *)fp->_p;
108 *lenp = len = p - fp->_p;
109 fp->_flags |= __SMOD;
117 * We have to copy the current buffered data to the line buffer.
118 * As a bonus, though, we can leave off the __SMOD.
120 * OPTIMISTIC is length that we (optimistically) expect will
121 * accomodate the `rest' of the string, on each trip through the
124 #define OPTIMISTIC 80
126 for (len = fp->_r, off = 0;; len += fp->_r) {
130 * Make sure there is room for more bytes. Copy data from
131 * file buffer to line buffer, refill file and look for
132 * newline. The loop stops only when we find a newline.
134 if (slbexpand(fp, len + OPTIMISTIC))
136 (void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p,
140 break; /* EOF or error: return partial line */
141 if ((p = memchr((void *)fp->_p, '\n', (size_t)fp->_r)) == NULL)
144 /* got it: finish up the line (like code above) */
148 if (slbexpand(fp, len))
150 (void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p,
158 fp->_lb._base[len] = 0;
161 return ((char *)fp->_lb._base);
166 return (NULL); /* ??? */