The following variables can be accessed only on UNIX. These variables have been superseded by the functions listed in “Functions for Returning System Variables”, which are available on all platforms. In all cases, these variables should be considered READ-ONLY:

 

IDL System Variable	Internal Variable	Type
!DIR	IDL_SysvDir	IDL_STRING
!VERSION.ARCH	IDL_SysvVersion.arch	IDL_STRING
!VERSION.OS	IDL_SysvVersion.os	IDL_STRING
!VERSION.OS_FAMILY	IDL_SysvVersion.os_family	IDL_STRING
!VERSION.RELEASE	IDL_SysvVersion.release	IDL_STRING
!ERR	IDL_SysvErrCode	IDL_LONG
!ERROR	IDL_SysvErrorCode	IDL_LONG
!ORDER	IDL_SysvOrder	IDL_LONG

!ORDER IDL_SysvOrder IDL_LONG

In addition, the following function has been superseded by the

IDL_SysvErrorCodeValue( ) function:

IDL_LONG IDL_SysvErrCodeValue(void)

This function returns the value of !ERR.