ExifTool Forum

I am trying to copy the filename to subject, removing underscores and filename extension:

exiftool -r -overwrite_original '-subject<${filename;s/\.[^\.]+$|_/ /g}' 'PATHtoFILEorDIRECTORY'


Which does exactly what I told it to, including replacing the filename extension with a space... However for good form, I would like to remove this trailing space. A case of just knowing enough to be dangerous I guess!

I poked around the forum and came up with the following:

exiftool -r -overwrite_original '-subject<${filename;s/\.[^\.]+$|_/ /g;-subject;s/\s+$//}' 'PATHtoFILEorDIRECTORY'

Which appears to remove the trailing white space, however it presents the following warning:

Warning: Useless use of negation (-) in void context for 'filename'

So is there a better way to do this with my original regex? If not, where have I gone wrong with the syntax combining the two regex and the subject tag? I of course tried subject without the hyphen, however this did not work.

Warning: Bareword "subject" not allowed while "strict subs" in use for 'filename'

Remove the 2nd -subect.

edit:
Now that I'm home and off mobile, I can be more clear.   The second -subject; doesn't do anything and is the source of the error.  It should be removed.  Try this for your command:
exiftool -r -overwrite_original '-subject<${filename;s/\.[^\.]+$|_/ /g;s/\s+$//}' 'PATHtoFILEorDIRECTORY'

Thank you StarGeek!

So it appears to come down to adding three characters in order to string together two separate regex commands:

;s/

Is that correct?

Of course, when I went searching the web for info on combining separate Perl regular expressions, I did not find anything that simple... and the forum reference that got me half way there was from a different discussion (tag to filename, not filename to tag, so the syntax was different).

So rather than using the piple | for a "or" operator, I could achieve the same end result by stringing together three separate regex:

exiftool -r -overwrite_original '-subject<${filename;s/\.[^\.]+$/ /g;s/_/ /g;s/\s+$//}' 'PATHtoFILEorDIRECTORY'

EDIT:

Now that I think about it, I can now construct a better regex that only uses two expressions, without the need to correct the unwanted space as I no longer need to use the | pipe construct:

exiftool -r -overwrite_original '-subject<${filename;s/\.[^\.]+$//;s/_/ /g}' 'PATHtoFILEorDIRECTORY'

Thank you!

Quote from: Stephen Marsh on August 06, 2017, 04:42:29 PM
Thank you StarGeek!

So it appears to come down to adding three characters in order to string together two separate regex commands:

;s/

Is that correct?

Not quite.  It's the semicolon alone that indicates a separate statement.  The s/ is the start of a new regex substitution, but you can use a completely different perl command, such as tr or even something as complex as map or grep or even define a new variable with my.

Thanks again StarGeek, I think did see tr in another topic, however I could not get it to work in a different context. This is really useful!