rt-thread/components/libc/compilers/common/cstdio.c

/*
 * Copyright (c) 2006-2022, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2014-05-22     ivanrad      implement getline
 */

#include "posix/stdio.h"
#include <stdlib.h>
#include <limits.h>
#include <sys/errno.h>

ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream)
{
    char *cur_pos, *new_lineptr;
    size_t new_lineptr_len;
    int c;

    if (lineptr == NULL || n == NULL || stream == NULL)
    {
        errno = EINVAL;
        return -1;
    }

    if (*lineptr == NULL)
    {
        *n = 128; /* init len */
        if ((*lineptr = (char *)malloc(*n)) == NULL)
        {
            errno = ENOMEM;
            return -1;
        }
    }

    cur_pos = *lineptr;
    for (;;)
    {
        c = getc(stream);

        if (ferror(stream) || (c == EOF && cur_pos == *lineptr))
            return -1;

        if (c == EOF)
            break;

        if ((*lineptr + *n - cur_pos) < 2)
        {
            if (LONG_MAX / 2 < *n)
            {
#ifdef EOVERFLOW
                errno = EOVERFLOW;
#else
                errno = ERANGE; /* no EOVERFLOW defined */
#endif
                return -1;
            }
            new_lineptr_len = *n * 2;

            if ((new_lineptr = (char *)realloc(*lineptr, new_lineptr_len)) == NULL)
            {
                errno = ENOMEM;
                return -1;
            }
            cur_pos = new_lineptr + (cur_pos - *lineptr);
            *lineptr = new_lineptr;
            *n = new_lineptr_len;
        }

        *cur_pos++ = (char)c;

        if (c == delim)
            break;
    }

    *cur_pos = '\0';
    return (ssize_t)(cur_pos - *lineptr);
}

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