mirror of
https://github.com/freebsd/freebsd-src.git
synced 2024-12-02 23:43:25 +00:00
105 lines
3.3 KiB
C
105 lines
3.3 KiB
C
/*-
|
|
* Copyright (c) 1990, 1993
|
|
* The Regents of the University of California. 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[] = "@(#)fgets.c 8.2 (Berkeley) 12/22/93";
|
|
#endif /* LIBC_SCCS and not lint */
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
|
|
/*
|
|
* Read at most n-1 characters from the given file.
|
|
* Stop when a newline has been read, or the count runs out.
|
|
* Return first argument, or NULL if no characters were read.
|
|
*/
|
|
char *
|
|
fgets(buf, n, fp)
|
|
char *buf;
|
|
register size_t n;
|
|
register FILE *fp;
|
|
{
|
|
register size_t len;
|
|
register char *s;
|
|
register unsigned char *p, *t;
|
|
|
|
if (n == 0) /* sanity check */
|
|
return (NULL);
|
|
|
|
s = buf;
|
|
n--; /* leave space for NUL */
|
|
while (n != 0) {
|
|
/*
|
|
* If the buffer is empty, refill it.
|
|
*/
|
|
if ((len = fp->_r) <= 0) {
|
|
if (__srefill(fp)) {
|
|
/* EOF/error: stop with partial or no line */
|
|
if (s == buf)
|
|
return (NULL);
|
|
break;
|
|
}
|
|
len = fp->_r;
|
|
}
|
|
p = fp->_p;
|
|
|
|
/*
|
|
* Scan through at most n bytes of the current buffer,
|
|
* looking for '\n'. If found, copy up to and including
|
|
* newline, and stop. Otherwise, copy entire chunk
|
|
* and loop.
|
|
*/
|
|
if (len > n)
|
|
len = n;
|
|
t = memchr((void *)p, '\n', len);
|
|
if (t != NULL) {
|
|
len = ++t - p;
|
|
fp->_r -= len;
|
|
fp->_p = t;
|
|
(void)memcpy((void *)s, (void *)p, len);
|
|
s[len] = 0;
|
|
return (buf);
|
|
}
|
|
fp->_r -= len;
|
|
fp->_p += len;
|
|
(void)memcpy((void *)s, (void *)p, len);
|
|
s += len;
|
|
n -= len;
|
|
}
|
|
*s = 0;
|
|
return (buf);
|
|
}
|