FILEREAD: file verification tool

Description

Reads any file and checks on its internal integrity, producing a report. All types of files may be checked. Used to check for concealed file damage.

Categories

System Operation
Disk Management

Related files

FILEREAD: Object file for program.

DISPLAY: The Wang DISPLAY utility is used to display the error report, if desired.

User Instructions

FILEREAD opens selected files and attempts to read them on a record basis. It can be used to check files for damage after a system crash or during a backup operation. The analysis is more thorough than the reorganization option of COPY, but does not pinpoint record errors like the Wang VERIFY utility.

To use, enter the name of the file, library, or volume to be examined and select the mode. BRIEF mode (the default) checks the data blocks of all files, including indexed files; FULL mode also reads through all index chains on indexed files and reports on their integrity. FILEREAD requires exclusive access to the files, and open files will return an error message from the OPEN SVC.

When all files have been examined, the program returns to the INPUT screen. The user may process additional files, display the listing created by the last run, or exit the program. The listing shows the file, library, and volume and the message ID and originator for all errors. Only one error per file is shown, since FILEREAD does not continue its analysis after an error occurs.

Errors can be associated with the file parameters (READFDR), the disk catalog (READVTOC), or various disk errors (DMS errors, etc.). The FILEREAD utility will also generate error messages for discrepancies in index count or for files not properly closed.

Programmer Instructions

FILEREAD may be run under program control through a program or procedure. The return code from FILEREAD indicates the number of errors encountered during analysis.

INPUT       Press (RETURN) to continue, PF(14) to examine
            listing (after run), or PF(16) to exit program.

  FILE      (blank)     The name and location of the file,
  LIBRARY   (blank)     library, or volume to be examined.
  VOLUME    (blank)     Leave FILE blank for library
                        analysis, FILE and LIBRARY blank for
                        volume analysis.

  MODE      BRIEF       Set to FULL for complete analysis of
                        indexed files.

Example of use

FILEREAD can find submerged DMS errors that could prove disastrous during critical operations; for this reason, it might be run regularly against critical files and volume. For example, a misplaced byte in a compressed file might render the entire block useless and abort a restore from tape, but FILEREAD can find such errors before the tape is prepared.

Comments

Why isn't this utility generally available?