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

#include "stdio_impl.h"

int __fseeko_unlocked(FILE *f, off_t off, int whence)
{
        /* Adjust relative offset for unread data in buffer, if any. */
        if (whence == SEEK_CUR) off -= f->rend - f->rpos;

        /* Flush write buffer, and report error on failure. */
        if (f->wpos > f->wbase) {
                f->write(f, 0, 0);
                if (!f->wpos) return -1;
        }

        /* Leave writing mode */
        f->wpos = f->wbase = f->wend = 0;

        /* Perform the underlying seek. */
        if (f->seek(f, off, whence) < 0) return -1;

        /* If seek succeeded, file is seekable and we discard read buffer. */
        f->rpos = f->rend = 0;
        f->flags &= ~F_EOF;
        
        return 0;
}

int __fseeko(FILE *f, off_t off, int whence)
{
        int result;
        FLOCK(f);
        result = __fseeko_unlocked(f, off, whence);
        FUNLOCK(f);
        return result;
}

int fseek(FILE *f, long off, int whence)
{
        return __fseeko(f, off, whence);
}

weak_alias(__fseeko, fseeko);

LFS64(fseeko);