getline.c
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/* getline.c -- Replacement for GNU C library function getline
Copyright (C) 1993, 1996, 2001 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Written by Jan Brittenson, bson@gnu.ai.mit.edu. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
/* The `getdelim' function is only declared if the following symbol
is defined. */
#define _GNU_SOURCE 1
#include <stdio.h>
#include <sys/types.h>
#if defined __GNU_LIBRARY__ && HAVE_GETDELIM
ssize_t
getline (lineptr, n, stream)
char **lineptr;
size_t *n;
FILE *stream;
{
return getdelim (lineptr, n, '\n', stream);
}
#else /* ! have getdelim */
# define NDEBUG
# include <assert.h>
# if STDC_HEADERS
# include <stdlib.h>
# else
char *malloc (), *realloc ();
# endif
/* Always add at least this many bytes when extending the buffer. */
# define MIN_CHUNK 64
/* Read up to (and including) a TERMINATOR from STREAM into *LINEPTR
+ OFFSET (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. Return the number of characters read (not including the
null terminator), or -1 on error or EOF. */
ssize_t
getstr (lineptr, n, stream, terminator, offset)
char **lineptr;
size_t *n;
FILE *stream;
char terminator;
size_t offset;
{
int nchars_avail; /* Allocated but unused chars in *LINEPTR. */
char *read_pos; /* Where we're reading into *LINEPTR. */
int ret;
if (!lineptr || !n || !stream)
return -1;
if (!*lineptr)
{
*n = MIN_CHUNK;
*lineptr = malloc (*n);
if (!*lineptr)
return -1;
}
nchars_avail = *n - offset;
read_pos = *lineptr + offset;
for (;;)
{
register int c = getc (stream);
/* We always want at least one char left in the buffer, since we
always (unless we get an error while reading the first char)
NUL-terminate the line buffer. */
assert(*n - nchars_avail == read_pos - *lineptr);
if (nchars_avail < 2)
{
if (*n > MIN_CHUNK)
*n *= 2;
else
*n += MIN_CHUNK;
nchars_avail = *n + *lineptr - read_pos;
*lineptr = realloc (*lineptr, *n);
if (!*lineptr)
return -1;
read_pos = *n - nchars_avail + *lineptr;
assert(*n - nchars_avail == read_pos - *lineptr);
}
if (c == EOF || ferror (stream))
{
/* Return partial line, if any. */
if (read_pos == *lineptr)
return -1;
else
break;
}
*read_pos++ = c;
nchars_avail--;
if (c == terminator)
/* Return the line. */
break;
}
/* Done - NUL terminate and return the number of chars read. */
*read_pos = '\0';
ret = read_pos - (*lineptr + offset);
return ret;
}
ssize_t
getline (lineptr, n, stream)
char **lineptr;
size_t *n;
FILE *stream;
{
return getstr (lineptr, n, stream, '\n', 0);
}
ssize_t
getdelim (lineptr, n, delimiter, stream)
char **lineptr;
size_t *n;
int delimiter;
FILE *stream;
{
return getstr (lineptr, n, stream, delimiter, 0);
}
#endif