4.6.2 Output of `--version'

The `--version' output is meant not only to give the program name, but to give a precise reference to where the actual sources for the program can be found. One asset of GNU is that all sources are available. It should never be difficult to discover and grab the proper sources for any given executable program or script.

A few maintenance scripts may depend of a rather precise format for `--version' output, which is now detailed. The output should consist of only one line containing many fields separated with a single space. >From left to right, these fields are:

• The program name, at least when it is different from the package name, or when specific program version numbers follow. When a single package distributes many programs, the program name is always given.
• The program version numbers, but only if they differ from the version numbers of the whole package. This happens, rather unfrequently, when a single package distributes programs which are maintained by different people, each using his own version scheme (e.g. the Texinfo distribution).
• A single dash `-' character, surrounded by one space on each side, of course. This string is used in case both the program name and the package name are given. When only the package and package version numbers are given, it is assumed that the program name is identical to the package name, and that program version numbers are the same as the package version numbers. In this case, this single dash is omitted.
• The optional word `GNU', all in capitals.
• The mandatory package name.
• The mandatory version numbers for the package name.

If package is the package name and version are the package version numbers, then package-version.tar.gz should be the exact name of the archive file containing the distribution, exact even to the capitalization.

Here are some examples:

     cat - GNU textutils 1.19c
     msgfmt - GNU gettext 0.10.24
     GNU recode 3.4.2

We use `-' instead of words like `from', and avoid using the word `version' between names and numbers, in hope to escape the need of internationalising `--version' output.