source: asp3_tinet_ecnl_rx/trunk/musl-1.1.18/src/stdio/__fdopen.c@ 337

#include "stdio_impl.h"
#include <stdlib.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>

FILE *__fdopen(int fd, const char *mode)
{
        FILE *f;
        struct winsize wsz;

        /* Check for valid initial mode character */
        if (!strchr("rwa", *mode)) {
                errno = EINVAL;
                return 0;
        }

        /* Allocate FILE+buffer or fail */
        if (!(f=malloc(sizeof *f + UNGET + BUFSIZ))) return 0;

        /* Zero-fill only the struct, not the buffer */
        memset(f, 0, sizeof *f);

        /* Impose mode restrictions */
        if (!strchr(mode, '+')) f->flags = (*mode == 'r') ? F_NOWR : F_NORD;

        /* Apply close-on-exec flag */
        if (strchr(mode, 'e')) __syscall(SYS_fcntl, fd, F_SETFD, FD_CLOEXEC);

        /* Set append mode on fd if opened for append */
        if (*mode == 'a') {
                int flags = __syscall(SYS_fcntl, fd, F_GETFL);
                if (!(flags & O_APPEND))
                        __syscall(SYS_fcntl, fd, F_SETFL, flags | O_APPEND);
                f->flags |= F_APP;
        }

        f->fd = fd;
        f->buf = (unsigned char *)f + sizeof *f + UNGET;
        f->buf_size = BUFSIZ;

        /* Activate line buffered mode for terminals */
        f->lbf = EOF;
        if (!(f->flags & F_NOWR) && !__syscall(SYS_ioctl, fd, TIOCGWINSZ, &wsz))
                f->lbf = '\n';

        /* Initialize op ptrs. No problem if some are unneeded. */
        f->read = __stdio_read;
        f->write = __stdio_write;
        f->seek = __stdio_seek;
        f->close = __stdio_close;

        if (!libc.threaded) f->lock = -1;

        /* Add new FILE to open file list */
        return __ofl_add(f);
}

#ifndef __c2__
weak_alias(__fdopen, fdopen);
#else
FILE *fdopen(int fd, const char *mode)
{
        return __fdopen(fd, mode);
}
#endif