Mixing Option Styles
--------------------
All three styles may be intermixed in a single `tar' command, so
long as the rules for each style are fully respected(1). Old style
options and either of the modern styles of options may be mixed within
a single `tar' command. However, old style options must be introduced
as the first arguments only, following the rule for old options (old
options must appear directly after the `tar' command and some white
space). Modern options may be given only after all arguments to the
old options have been collected. If this rule is not respected, a
modern option might be falsely interpreted as the value of the argument
to one of the old style options.
For example, all the following commands are wholly equivalent, and
illustrate the many combinations and orderings of option styles.
tar --create --file=archive.tar
tar --create -f archive.tar
tar --create -farchive.tar
tar --file=archive.tar --create
tar --file=archive.tar -c
tar -c --file=archive.tar
tar -c -f archive.tar
tar -c -farchive.tar
tar -cf archive.tar
tar -cfarchive.tar
tar -f archive.tar --create
tar -f archive.tar -c
tar -farchive.tar --create
tar -farchive.tar -c
tar c --file=archive.tar
tar c -f archive.tar
tar c -farchive.tar
tar cf archive.tar
tar f archive.tar --create
tar f archive.tar -c
tar fc archive.tar
On the other hand, the following commands are _not_ equivalent to
the previous set:
tar -f -c archive.tar
tar -fc archive.tar
tar -fcarchive.tar
tar -farchive.tarc
tar cfarchive.tar
These last examples mean something completely different from what the
user intended (judging based on the example in the previous set which
uses long options, whose intent is therefore very clear). The first
four specify that the `tar' archive would be a file named `-c', `c',
`carchive.tar' or `archive.tarc', respectively. The first two examples
also specify a single non-option, NAME argument having the value
`archive.tar'. The last example contains only old style option letters
(repeating option `c' twice), not all of which are meaningful (eg., `.',
`h', or `i'), with no argument value.
---------- Footnotes ----------
(1) Before GNU `tar' version 1.11.6, a bug prevented intermixing old
style options with mnemonic options in some cases.