The MPE/iX shell does not provide a way to distinguish files containing executable scripts from other files. However, the POSIX standard requires that file permission bits should be checked to verify that execute access has been granted to at least one of the file classes.
When ALL access would normally be granted to a user, X access is handled as a special case. Users with appropriate privilege are granted X access only if the file has an executable file code (PROG, SL, NMPRG, or NMXL), if the file access matrix assigns X access to the user, or if the file has an ACD that assigns X access to at least one user.
The file creator is granted X access only if the $OWNER ACD entry grants X access. If the $OWNER entry does not exist, the file creator is granted X access if the file has an executable file code or at least one user is granted X access by the file access matrix or an ACD.
A RELEASEd file grants X access only if it has an executable file code.
Users with appropriate privilege still get X access to files with executable file codes. X is also used to grant STREAM access to JOB files. Users with appropriate privilege can still stream these files because they have R access to the files.
