3.6 Obtaining GNU tar default values

GNU tar has some predefined defaults that are used when you do not explicitly specify another values. To obtain a list of such defaults, use --show-defaults option. This will output the values in the form of tar command line options:

     tar --show-defaults
     --format=gnu -f- -b20 --quoting-style=escape
     --rmt-command=/etc/rmt --rsh-command=/usr/bin/rsh

Notice, that this option outputs only one line. The example output above has been split to fit page boundaries.

The above output shows that this version of GNU tar defaults to using ‘gnu’ archive format (see Formats), it uses standard output as the archive, if no --file option has been given (see file tutorial), the default blocking factor is 20 (see Blocking Factor). It also shows the default locations where tar will look for rmt and rsh binaries.