fseek.c

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#include <stdio.h>
#include <sys/io.h>
 
#include "user/common/file.h"
 
int fseek(FILE* stream, long offset, int whence)
{
    mtx_lock(&stream->mtx);
 
    if (stream->flags & _FILE_WRITE)
    {
        if (_file_flush_buffer(stream) == ERR)
        {
            mtx_unlock(&stream->mtx);
            return EOF;
        }
    }
 
    stream->flags &= ~_FILE_EOF;
 
    if (stream->flags & _FILE_RW)
    {
        stream->flags &= ~(_FILE_READ | _FILE_WRITE);
    }
 
    if (whence == SEEK_CUR)
    {
        offset -= (((int)stream->bufEnd - (int)stream->bufIndex) + stream->ungetIndex);
    }
 
    uint64_t result = (_file_seek(stream, offset, whence) != ERR) ? 0 : EOF;
    mtx_unlock(&stream->mtx);
    return result;
}