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/* Part of publib.
Copyright (c) 1994-2006 Lars Wirzenius. 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.
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.
*/
/*
* getaline.c -- read arbitrarily long line from file
*
* Part of publib. See man page for more information
* "@(#)publib-files:$Id: getaline.c,v 1.4 1996/04/28 14:01:19 liw Exp $"
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "publib/errormsg.h"
#include "publib/files.h"
char *getaline(FILE *f) {
char *buf; /* buffer for line */
size_t size; /* size of buffer */
size_t inc; /* how much to enlarge buffer */
size_t len; /* # of chars stored into buf before '\0' */
char *p;
const size_t thres = 128; /* initial buffer size (most lines should
fit into this size, so think of this as
the "long line threshold"). */
const size_t mucho = 128; /* if there is at least this much wasted
space when the whole buffer has been
read, try to reclaim it. Don't make
this too small, else there is too much
time wasted trying to reclaim a couple
of bytes. */
const size_t mininc = 64; /* minimum number of bytes by which
to increase the allocated memory */
len = 0;
size = thres;
buf = malloc(size);
if (buf == NULL) {
__publib_error("malloc failed");
return NULL;
}
while (fgets(buf+len, size-len, f) != NULL) {
len += strlen(buf+len);
if (len > 0 && buf[len-1] == '\n')
break; /* the whole line has been read */
for (inc = size, p = NULL; inc > mininc; inc /= 2)
if ((p = realloc(buf, size + inc)) != NULL)
break;
if (p == NULL) {
__publib_error("realloc failed");
free(buf);
return NULL; /* couldn't get more memory */
}
size += inc;
buf = p;
}
if (len == 0) {
if (ferror(f))
__publib_error("I/O error");
free(buf);
return NULL; /* nothing read (eof or error) */
}
if (buf[len-1] == '\n') /* remove newline, if there */
buf[--len] = '\0';
if (size - len > mucho) { /* a plenitude of unused memory? */
p = realloc(buf, len+1);
if (p != NULL) {
buf = p;
size = len+1;
}
}
return buf;
}
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