Tar

Extract specific file

tar xvf tarball.tar path/to/file

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Extract into a directory

tar xvf tarball.tar -C dest_dir

Flat extraction (remove first directory)

tar xvf tarball.tar --strip-components=1

Search a file

tar tf archive.tar | grep file

Search if a string is present into files of multiple archives

find . -name \*.tar.gz -print0 | xargs -0 zgrep "STRING"

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Original size of a file (with no unzip)

tar ztvf archive.tar.gz -v --wildcards '*file.txt'