Which directories were archived? Command-line

I archived a directory. It took two hours, then exited with a non-zero exit status (that means an error). Hmm — I was just testing something; I only cared if certain specific subdirectories were present in the archive. So I needed a way to look deep inside, quickly, and find those particular directories.

GNU tar will let you “test” an archive with -t, but I only wanted a list of the directories archived. Then I wanted that sorted. So…

$ nice tar -tjvf data.tar.bz2 | tr -s ' ' | cut -d' ' -f 6- | cut -d / -f -2 > tardirs.txt
$ uniq tardirs.txt > tardirs_uniq.txt
$ sort tardirs_uniq.txt > tardirs_uniq_sorted.txt

The -tjvf arguments to tar let you look inside, the “tr” command collapses adjacent spaces so that the first “cut” command will output only the sixth (file) field, and the second “cut” command will reduce a directory like “folder/folder/folder/fun.txt” to “folder/folder.” Then “uniq” will remove non-unique names.