Opens the file for reading. It must exists. Also reads file header.
* It will try to identify the file format.
* See also \ref imErrorCodes. \n
* In Lua the IM file metatable name is "imFile".
* When converted to a string will return "imFile(%p)" where %p is replaced by the userdata address.
* If the file is already closed by im.FileClose, then it will return also the suffix "-closed".
*
* \verbatim im.FileOpen(file_name: string) -> ifile: imFile, error: number [in Lua 5] \endverbatim
* \ingroup file
Opens the file for reading. It must exists. Also reads file header. * It will try to identify the file format. * See also \ref imErrorCodes. \n * In Lua the IM file metatable name is "imFile". * When converted to a string will return "imFile(%p)" where %p is replaced by the userdata address. * If the file is already closed by im.FileClose, then it will return also the suffix "-closed". * * \verbatim im.FileOpen(file_name: string) -> ifile: imFile, error: number [in Lua 5] \endverbatim * \ingroup file