port/stdio/getline.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include "lint.h"
#include "file64.h"
#include "mtlib.h"
#include <stdio.h>
#include <errno.h>
#include <thread.h>
#include <synch.h>
#include <unistd.h>
#include <limits.h>
#include <malloc.h>
#include <sys/types.h>
#include "stdiom.h"

#define LINESZ  128 /* initial guess for a NULL *lineptr */

ssize_t
getdelim(char **_RESTRICT_KYWD lineptr, size_t *_RESTRICT_KYWD n,
    int delimiter, FILE *_RESTRICT_KYWD iop)
{
    rmutex_t *lk;
    char *ptr;
    size_t size;
    int c;
    size_t cnt;

    if (lineptr == NULL || n == NULL ||
        delimiter < 0 || delimiter > UCHAR_MAX) {
        errno = EINVAL;
        return (-1);
    }

    if (*lineptr == NULL || *n < LINESZ) {  /* initial allocation */
        if ((*lineptr = realloc(*lineptr, LINESZ)) == NULL) {
            errno = ENOMEM;
            return (-1);
        }
        *n = LINESZ;
    }
    ptr = *lineptr;
    size = *n;
    cnt = 0;

    FLOCKFILE(lk, iop);

    _SET_ORIENTATION_BYTE(iop);

    do {
        c = (--iop->_cnt < 0) ? __filbuf(iop) : *iop->_ptr++;
        if (c == EOF)
            break;
        *ptr++ = c;
        if (++cnt == size) {    /* must reallocate */
            if ((ptr = realloc(*lineptr, 2 * size)) == NULL) {
                FUNLOCKFILE(lk);
                ptr = *lineptr + size - 1;
                *ptr = '\0';
                errno = ENOMEM;
                return (-1);
            }
            *lineptr = ptr;
            ptr += size;
            *n = size = 2 * size;
        }
    } while (c != delimiter);

    *ptr = '\0';

    FUNLOCKFILE(lk);
    if (cnt > SSIZE_MAX) {
        errno = EOVERFLOW;
        return (-1);
    }
    return (cnt ? cnt : -1);
}

ssize_t
getline(char **_RESTRICT_KYWD lineptr, size_t *_RESTRICT_KYWD n,
    FILE *_RESTRICT_KYWD iop)
{
    return (getdelim(lineptr, n, '\n', iop));
}