Logging all warning and errors in a single directory

[neebah]

Is there a command line command for logging all errors by file for everything in a directory

[StarGeek]

You can get some info by using a command like
exiftool -if "$error or $warning" -error -warning DIR
but there are many errors that don't get flagged unless the file is actually being changed.  Exiftool isn't designed to validate images (see FAQ 25).  Also check this thread.