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/*-
* Copyright (c) 1990 The Regents of the University of California.
* Copyright (c) 1993, 1994 Chris Provenzano.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
/*static char *sccsid = "from: @(#)fgetline.c 5.2 (Berkeley) 5/4/91";*/
static char *rcsid = "$Id$";
#endif /* LIBC_SCCS and not lint */
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "local.h"
/*
* Expand the line buffer. Return -1 on error.
* The `new size' does not account for a terminating '\0',
* so we add 1 here.
*/
__slbexpand(fp, newsize)
FILE *fp;
size_t newsize;
{
void *p;
if (fp->_lb._size >= ++newsize)
return (0);
if ((p = realloc(fp->_lb._base, newsize)) == NULL)
return (-1);
fp->_lb._base = p;
fp->_lb._size = newsize;
return (0);
}
/*
* Get an input line. The returned pointer often (but not always)
* points into a stdio buffer. Fgetline smashes the newline (if any)
* in the stdio buffer; callers must not use it on streams that
* have `magic' setvbuf() games happening.
*/
char *
fgetline(fp, lenp)
register FILE *fp;
size_t *lenp;
{
register unsigned char *p;
register size_t len;
size_t off;
flockfile(fp);
/* make sure there is input */
if (fp->_r <= 0 && __srefill(fp)) {
if (lenp != NULL)
*lenp = 0;
funlockfile(fp);
return (NULL);
}
/* look for a newline in the input */
if ((p = memchr((void *)fp->_p, '\n', fp->_r)) != NULL) {
register char *ret;
/*
* Found one. Flag buffer as modified to keep
* fseek from `optimising' a backward seek, since
* the newline is about to be trashed. (We should
* be able to get away with doing this only if
* p is not pointing into an ungetc buffer, since
* fseek discards ungetc data, but this is the
* usual case anyway.)
*/
ret = (char *)fp->_p;
len = p - fp->_p;
fp->_flags |= __SMOD;
*p = 0;
fp->_r -= len + 1;
fp->_p = p + 1;
if (lenp != NULL)
*lenp = len;
funlockfile(fp);
return (ret);
}
/*
* We have to copy the current buffered data to the line buffer.
*
* OPTIMISTIC is length that we (optimistically)
* expect will accomodate the `rest' of the string,
* on each trip through the loop below.
*/
#define OPTIMISTIC 80
for (len = fp->_r, off = 0;; len += fp->_r) {
register size_t diff;
/*
* Make sure there is room for more bytes.
* Copy data from file buffer to line buffer,
* refill file and look for newline. The
* loop stops only when we find a newline.
*/
if (__slbexpand(fp, len + OPTIMISTIC))
goto error;
(void) memcpy((void *)(fp->_lb._base + off), (void *)fp->_p,
len - off);
off = len;
if (__srefill(fp))
break; /* EOF or error: return partial line */
if ((p = memchr((void *)fp->_p, '\n', fp->_r)) == NULL)
continue;
/* got it: finish up the line (like code above) */
fp->_flags |= __SMOD; /* soon */
diff = p - fp->_p;
len += diff;
if (__slbexpand(fp, len))
goto error;
(void) memcpy((void *)(fp->_lb._base + off), (void *)fp->_p, diff);
fp->_r -= diff + 1;
fp->_p = p + 1;
break;
}
if (lenp != NULL)
*lenp = len;
fp->_lb._base[len] = 0;
funlockfile(fp);
return ((char *)fp->_lb._base);
error:
if (lenp != NULL)
*lenp = 0; /* ??? */
funlockfile(fp);
return (NULL); /* ??? */
}
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