Protection modes
Protection modes specify read, write, and execute rights for a protected object and a given user.
Information about an object’s protection mode usually takes the form of a single-character
abbreviation of each Boolean value in the protection mode; these abbreviations are displayed in
Table 1.
User category | Read permission | Write permission | Execute permission |
---|---|---|---|
Object owner | Yes (r ) or No (- ) |
Yes (w ) or No (- ) |
Yes (x ) or No (- ) |
Member of object’s group | Yes (r ) or No (- ) |
Yes (w ) or No (- ) |
Yes (x ) or No (- ) |
Other | Yes (r ) or No (- ) |
Yes (w ) or No (- ) |
Yes (x ) or No (- ) |
For example, suppose you are working in a view and want to see the protection mode for a directory element named lib. Suppose the owner and group of lib have read, write, and execute permission, but other users have only read and execute permissions. The cleartool describe command displays the mode, along with the elements owner (akp) and group (clearusers), as follows:
cleartool describe lib
...
Element Protection:
User : akp rwx
Group: clearusers rwx
Other: r-x
...
In addition to these single-character abbreviations, integers are sometimes used to display
object permissions in a compact form. For each user category (owner, group, and others), a single
digit from 0 through 7 represents the permissions for that category, as described in Table 2.
Digit | Read permission | Write permission | Execute permission |
---|---|---|---|
0 | No | No | No |
1 | No | No | Yes |
2 | No | Yes | No |
3 | No | Yes | Yes |
4 | Yes | No | No |
5 | Yes | No | Yes |
6 | Yes | Yes | No |
7 | Yes | Yes | Yes |
A sequence of three digits expresses the protection mode for an object,
in this order: owner’s permissions, group’s permissions, others’ permissions.
For example, the protection mode 750 for an object means that it has these
permissions:
Digit | User category | Permissions |
7 | Owner | Read, write, execute |
5 | Group | Read, execute |
0 | Others | None |