Failure of Commands 

Commands could fail for a number of reasons. Some reasons are listed below : 

·        A command invokes an executable that is missing in the defined path. 

·        When a command invokes an executable, the executable is required to create an output file. Sometimes, the command for creating such a file could fail because of lack of disk space or lack of permissions to a folder. 

·        If a command runs a script on a database, then the script may fail if the connection to the database cannot be established. This could happen if the DSN is not properly configured or if the SQL Server service is not running.

·        A command to delete a file could fail (on Windows 2000, not Windows NT) if the file is not present on the target machine.

·        A command to move or copy a file to a destination could fail if the source or target file is in use. It could also fail if the destination folder is marked as ‘ReadOnly’.

·        A command that contains a path could fail (on Windows NT) if the path contains spaces. Hence, all the file paths within a command string must be enclosed with quotation marks ( “ and “ ).

·        If a command uses registry variables (as above) or environment variables (like %WINDIR% ), then the command would fail if these are not present. In such cases, the log file will show that the Registry or Environment variable has not been resolved correctly.