On your import comman line use the SHOW=Y option. This option will cause import to go through all the steps of importing, without every doing the actual import. If the file is corrupted, it will fail. Below is the fragment on the option from the manual.
When SHOW=Y, the contents of the export file are listed to the display and not imported. The SQL statements contained in the export are displayed in the order in which Import will execute them.
The SHOW parameter can be used only with the FULL=Y, FROMUSER, TOUSER, or TABLES parameters.
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