TOPS-20 Commands Reference Manual
EXPUNGE
Permanently erases all the deleted files from a directory.
Format
@EXPUNGE (DIRECTORY) dev:<directory>, @@subcommand
where:
| dev:<directory> | is the name of the directory you wish to expunge; you may use wildcard
characters to expunge more than one directory.
| ||||||
| @@subcommand | means that after a final comma you can give one or more optional subcommands on successive lines. | ||||||
| DELETE | deletes and expunges temporary files (those with the Temporary (;T) attribute) created by some system programs to hold interim data. Do not use if you will have any further need of these files. | ||||||
| PURGE | expunges all files which you have opened but not closed. | ||||||
| REBUILD | rebuilds the symbol table of the directory named. |
Output
After a successful EXPUNGE command, the system reports the number of disk pages freed with the message [n pages freed]. If deleted files are mapped, they will not be expunged, and so will not contribute to the number of pages freed. Occasionally the system will report a negative number. This can mean that files were being written in the directory during the EXPUNGE, or (especially if you include the REBUILD subcommand) that previous computations of directory size had not adequately accounted for some files, for example, files written near the time of a system crash and reload.
Hints
Using the REBUILD Subcommand
The REBUILD subcommand is not needed under usual conditions, as the system performs this action automatically. Use REBUILD if a message is printed on your terminal advising you to rebuild the symbol table of a directory.
Using the PURGE Subcommand
The PURGE subcommand is useful chiefly for removing the remains of files that were being created at the time of a system crash or a structure dismount. Do not give it while anyone might be using the directory, because that user's program might be deprived of necessary files as a result.
Cannot CTRL/C
You cannot use <CTRL/C> to interrupt an EXPUNGE once it is started.
Special Cases
Files With the "Permanent" Attribute
The system erases only the contents of any files that have the Permanent attribute, for example your MAIL.TXT file, when you try to expunge them. The file specifications of permanent files remain among your deleted files, and cannot be removed by TOPS-20 commands.
Related Commands
| DELETE | for marking files to be later expunged |
| DIRECTORY-class commands | for obtaining lists of file specifications |
| INFORMATION DISK-USAGE | for finding out the size of a directory |
| UNDELETE | for recovering deleted files |
Examples
- Expunge all deleted files from your directory.
@EXPUNGE PS:<LATTA> [6 pages freed]
- Find out how much of your disk space is in use and how much is occupied
by deleted files. Delete some of your backup files, then give the EXPUNGE
command to erase all of these.
@INFORMATION DISK-USAGE PS:<LATTA> 154 Pages assigned, 101 in use, 53 deleted 590 Working pages, 590 Permanent pages allowed 33371 Pages free on PS: @DELETE *.Q* BLUE.QAR.1 [OK] REMARK.QXT.1 [OK] RIMOUSKI.QXT.1 [OK] @EXPUNGE PS:<LATTA> [56 pages freed]