Error codes during file processing (DMS error codes)

In conjunction with file processing, return codes in the form yxxx occur in the event of an error. These are also known as DMS errors and have the following meanings:

y

The first character y denotes the function in which the error occurred. y may have the following values: A Error in loading shared memories into the address space C Error in close call D Error in signing off from a shared memory area F Error in fstat/stat call G Error in allocating shared memory L Error in lseek call O Error in open call R Error in read call W Error in write call X Error in create call

xxx

The three characters xxx represent, in printable form, the error number which is stored by the operating system in the external variable errno. The meanings of the individual error numbers are described in the operating system manuals and in the errno.h header file. You will find some of the error codes which occur most often in System error codes .

In addition, the errors CONS, LERR, OERR, REND, RERR, WERR, SXDE, SDDE and SDFE can occur.
These have the following meaning:

CONS	The data contents are inconsistent.
LERR	lseek could not be positioned at the desired point.
OERR	An attempt was made to open a directory as a normal file.
REND	End-of-file reached on reading from a file.
RERR	Insufficient bytes could be read.
WERR	Insufficient bytes could be written.
SXDE	A directory could not be created.
SDDE	A directory could not be deleted.
SDFE	A file could not be deleted.