glibc/stdio/getdelim.c
1995-02-18 01:27:10 +00:00

174 lines
4.0 KiB
C

/* Copyright (C) 1991, 1992, 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
/* Read up to (and including) a TERMINATOR from STREAM into *LINEPTR
(and null-terminate it). *LINEPTR is a pointer returned from malloc (or
NULL), pointing to *N characters of space. It is realloc'd as
necessary. Returns the number of characters read (not including the
null terminator), or -1 on error or EOF. */
ssize_t
DEFUN(__getdelim, (lineptr, n, terminator, stream),
char **lineptr AND size_t *n AND int terminator AND FILE *stream)
{
char *line, *p;
size_t size, copy;
if (!__validfp (stream) || lineptr == NULL || n == NULL)
{
errno = EINVAL;
return -1;
}
if (ferror (stream))
return -1;
/* Make sure we have a line buffer to start with. */
if (*lineptr == NULL || *n < 2) /* !seen and no buf yet need 2 chars. */
{
#ifndef MAX_CANON
#define MAX_CANON 256
#endif
line = realloc (*lineptr, MAX_CANON);
if (line == NULL)
return -1;
*lineptr = line;
*n = MAX_CANON;
}
line = *lineptr;
size = *n;
copy = size;
p = line;
if (stream->__buffer == NULL && stream->__userbuf)
{
/* Unbuffered stream. Not much optimization to do. */
while (1)
{
size_t len;
while (--copy > 0)
{
register int c = getc (stream);
if (c == EOF)
goto lose;
else if ((*p++ = c) == terminator)
goto win;
}
/* Need to enlarge the line buffer. */
len = p - line;
size *= 2;
line = realloc (line, size);
if (line == NULL)
goto lose;
*lineptr = line;
*n = size;
p = line + len;
copy = size - len;
}
}
else
{
/* Leave space for the terminating null. */
--copy;
if (!stream->__seen || stream->__buffer == NULL || stream->__pushed_back)
{
/* Do one with getc to allocate a buffer. */
int c = getc (stream);
if (c == EOF)
goto lose;
*p++ = c;
if (c == terminator)
goto win;
--copy;
}
while (1)
{
size_t i;
char *found;
i = stream->__get_limit - stream->__bufp;
if (i == 0)
{
/* Refill the buffer. */
int c = __fillbf (stream);
if (c == EOF)
goto lose;
*p++ = c;
if (c == terminator)
goto win;
--copy;
i = stream->__get_limit - stream->__bufp;
}
if (i > copy)
i = copy;
found = (char *) __memccpy ((PTR) p, stream->__bufp, terminator, i);
if (found != NULL)
{
stream->__bufp += found - p;
p = found;
goto win;
}
stream->__bufp += i;
p += i;
copy -= i;
if (copy == 0)
{
/* Need to enlarge the line buffer. */
size_t len = p - line;
size *= 2;
line = realloc (line, size);
if (line == NULL)
goto lose;
*lineptr = line;
*n = size;
p = line + len;
copy = size - len;
/* Leave space for the terminating null. */
--copy;
}
}
}
lose:
if (p == *lineptr)
return -1;
/* Return a partial line since we got an error in the middle. */
win:
*p = '\0';
return p - *lineptr;
}
weak_alias (__getdelim, getdelim)