C++程序  |  50行  |  1.21 KB

/*
 * Copyright 2012, The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <stdio.h>

ssize_t getline(char **lineptr, size_t *n, FILE *stream)
{
    char *ptr;

    ptr = fgetln(stream, n);

    if (ptr == NULL) {
        return -1;
    }

    /* Free the original ptr */
    if (*lineptr != NULL) free(*lineptr);

    /* Add one more space for '\0' */
    size_t len = n[0] + 1;

    /* Update the length */
    n[0] = len;

    /* Allocate a new buffer */
    *lineptr = malloc(len);

    /* Copy over the string */
    memcpy(*lineptr, ptr, len-1);

    /* Write the NULL character */
    (*lineptr)[len-1] = '\0';

    /* Return the length of the new buffer */
    return len;
}