TOPS-20 Commands Reference Manual
Allows you to read a file using read-only editor commands.
@PERUSE (FILE) /switch(es) filespec
|/switch(es)||are keywords that apply to the EDIT editor. For descriptions of these switches, see the /CREATE or EDIT commands.|
|filespec||is the name of the file you want to read.
The PERUSE command runs the EDIT system program in read-only mode. (However, see Special Cases - Using an Editor Other than EDIT, below.) PERUSE is actually the same as the EDIT /READONLY command. In EDIT /READONLY mode you can use only EDIT program switches and commands that do not modify the file.
Avoid Accidental File Modification
Use PERUSE when it is important to avoid the risk of accidentally modifying a file.
PERUSE Line in SWITCH.INI
Add a line to your SWITCH.INI file for use with the PERUSE command. (See Example 3.)
Using an Editor Other than EDIT
The CREATE, EDIT and PERUSE commands in this manual assume that these commands call on the program EDIT. If your job uses another editing program, for example, EDT, the switches and examples shown here will not be applicable.
The Editor used by the CREATE, EDIT and PERUSE commands is specified by the logical name EDITOR:. You can find out the name of this program by giving the command, INFORMATION LOGICAL-NAMES EDITOR:. The job-wide definition (if any) will be given first, followed by the system-wide definition; the job-wide definition prevails if both exist. If the definition of EDITOR: is SYS:EDIT.EXE, the CREATE, EDIT and PERUSE commands will function as described in this manual. Otherwise, you must consult the appropriate manual (for example, the EDT-20 Reference Manual) for information.
Listing Available EDIT Read-Only Switches and Commands
Many of the EDIT switches and commands that are displayed in response to a ? modify the file and do not function with PERUSE. If you give a file-modifying switch, the switch is ignored but no error message is displayed. If you give a file-modifying EDIT command, you receive the message %ILLEGAL COMMAND.
For further information on these switches and commands see the EDIT Reference Manual.
Effect on Memory
The PERUSE command clears any unkept forks from memory, then loads your edit program.
|CREATE||for creating new files|
|DIRECTORY-class commands||for getting lists of existing files|
|EDIT||for modifying files|
|TYPE||for printing files on your terminal|
- PERUSE a file
- PERUSE a file, ten lines at a time, and begin at line 100.
@PERUSE FILEX.FOR Read: FILEX.FOR.1 *P 00100 !THIS IS FILEX.FOR
@PERUSE /PLINES:10 FIND.BAS Read: FIND.BAS *P 100 00100 ! ADD ROUTINE 00200 FOR X = 0 TO 400 00300 IF X$(X) = "XXX" THEN GOTO 2050 00400 NEXT X 00500 PRINT STRING$(10,10);"FILE FULL"\SLEEP 4\GOTO 199 00600 PRINT E$ \LINPUT"ENTER THE NAME ";M$ 00700 IF M$ <> "" THEN LET X$(X) = M$ ELSE GOTO 199 00800 PRINT E$ \LINPUT"ENTER THE NUMBER ";O$ 00900 IF O$ <> "" THEN LET Y$(X) = O$ ELSE GOTO 199 01000 PRINT E$\INPUT"MORE NAMES TO ENTER ";D$ *E