NetBSD/usr.sbin/sup/source/read_line.c

136 lines
3.7 KiB
C

/* $NetBSD: read_line.c,v 1.8 2003/10/16 06:26:06 itojun Exp $ */
/*
* Copyright (c) 1994 Mats O Jansson <moj@stacken.kth.se>
* All rights reserved.
*
* 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 Mats O Jansson
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <sys/cdefs.h>
#if defined(lint) && defined(__RCSID)
__RCSID("$NetBSD: read_line.c,v 1.8 2003/10/16 06:26:06 itojun Exp $");
#endif
#include <sys/param.h>
#include <err.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "supcdefs.h"
#include "supextern.h"
/* read_line():
* Read a line from a file, parsing continuations ending in \
* and eliminating trailing newlines.
* Returns a pointer to an internal buffer that is reused upon
* next invocation.
*
* NOTE: if HAS_FPARSELN is not defined, delim and flags are currently unused.
*/
char *
read_line(FILE * fp, size_t * size, size_t * lineno, const char *delim,
int flags)
{
static char *buf;
#ifdef HAS_FPARSELN
if (buf != NULL)
free(buf);
return (buf = fparseln(fp, size, lineno, delim, flags));
#else
char *n;
#ifndef HAS_FGETLN
char sbuf[1024];
#endif
static int buflen;
size_t s, len;
char *ptr;
int cnt;
len = 0;
cnt = 1;
while (cnt) {
if (lineno != NULL)
(*lineno)++;
#ifdef HAS_FGETLN
if ((ptr = fgetln(fp, &s)) == NULL) {
if (size != NULL)
*size = len;
if (len == 0)
return NULL;
else
return buf;
}
#else
if ((ptr = fgets(sbuf, sizeof(sbuf) - 1, fp)) == NULL) {
if (len == 0)
return NULL;
else
return buf;
} else {
char *l;
if ((l = strchr(sbuf, '\n')) == NULL) {
if (sbuf[sizeof(sbuf) - 3] != '\\') {
s = sizeof(sbuf);
sbuf[sizeof(sbuf) - 2] = '\\';
sbuf[sizeof(sbuf) - 1] = '\0';
} else
s = sizeof(sbuf) - 1;
} else {
s = l - sbuf;
}
}
#endif
if (ptr[s - 1] == '\n') /* the newline may be missing at EOF */
s--; /* forget newline */
if (!s)
cnt = 0;
else {
if ((cnt = (ptr[s - 1] == '\\')) != 0)
s--; /* forget \\ */
}
if (len + s + 1 > buflen) {
n = realloc(buf, len + s + 1);
if (n == NULL)
err(1, "can't realloc");
buf = n;
buflen = len + s + 1;
}
memcpy(buf + len, ptr, s);
len += s;
buf[len] = '\0';
}
if (size != NULL)
*size = len;
return buf;
#endif /* HAS_FPARSELN */
}