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BASIC keyword
Keyword:	VERIFY
Abbreviation:	V Shift+E
Type:	Command
Token code:	-/$-
Handling routine in BASIC ROM:	-–- $-–-
List of all BASIC keywords

Remark: This article describes the BASIC-Command VERIFY in BASIC V2 at the Commodore 64.

Type: Command
General Programming-Syntax: VERIFY ["<filename>"] [,<device number>]

The BASIC-Command VERIFY is used for verifying files, which was written with the BASIC-Command SAVE on a storage medium, with the datas in the memory (RAM). This command can used directly or in programs.

The device number is needed for the computer, which relaised the correct storage device:

• datasette (device number 1)
• diskdrives (device numbers 8-15, optional first diskdrive 8, second diskdrive 9, etc.)

When isn't used a device number, the computer uses the first device: datasette.

Also can be used the command VERIFY for the datasette to fast-forward the cassette. With this method you can precaution that the new datas are written behind the old datas on tape. For comparing files on disks, it is important to use the filename, which can contained wildcards like * and ?.

During the data compare the BASIC message "VERIFYING" is showing. When the datas in the RAM aren't correct with the saved datas, the BASIC-error "?VERIFY ERROR" appears.

[edit] Examples

VERIFY 
(compare the first programfile on datasette)

VERIFY "FILENAME",8
(compare this file from diskdrive 8)

VERIFY "*",9
(compare the first program 9)

VERIFY FILE$,1
(compare the file, which is in the string FILE$ on tape)

10000 REM SUBROUTINE SAVE ON DISK WITH VERIFYING
10001 SAVE FILE$,8
10002 VERIFY FILE$,8
10003 RETURN