VMS Help  —  COBOL  Run-Time Messages, FILE_LOCKED
  File is locked by another program

  Explanation: The specified disk file has already been opened by
  another file connector, using file sharing options that prohibit
  the current program from opening the same file.  The program that
  successfully opened the file could be part of the same run-unit,
  or it could belong to a different person running another program.

  User Action: You must take the following actions:

      a. Check the program logic, and verify that the file
         being opened is the one you intended.

      b. If you expect that some cases will attempt to open a
         file that is already open, add a declarative procedure
         to handle this condition.

      c. If the file should be available for sharing, use the
         DCL command SHOW DEVICE /FILES to find the process that
         has the file open and locked.  In a clustered environment,
         perform this DCL command on each node in the cluster.

      d. Once you have identified the process, use the DCL command
         SHOW PROCESS /CONTINUOUS to find the program that is being
         executed.

      e. Check the program logic and the file sharing options for
         the program that has the file locked.
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