Common options

Certain options are available in all these programs. Rather than writing identical descriptions for each of the programs, they are described here. (In fact, every GNU program accepts (or should accept) these options.)

`--help'

Print a usage message listing all available options, then exit successfully.

`--version'

Print the version number, then exit successfully.

• Backup options: -b -S -V, in some programs.

Backup options

Some GNU programs (at least cp, mv, and ln) optionally make backups of files before writing new versions. These options control the details of these backups. The options are also briefly mentioned in the descriptions of the particular programs.

`-b'

`--backup'

Make backups of files that are about to be overwritten or removed. Without this option, the original versions are destroyed.

`-S suffix'

`--suffix=suffix'

Append suffix to each backup file made with `-b'. If this option is not specified, the value of the SIMPLE_BACKUP_SUFFIX environment variable is used. And if SIMPLE_BACKUP_SUFFIX is not set, the default is `~', just as in Emacs.

`-V method'

`--version-control=method'

Use method to determine the type of backups made with `-b'. If this option is not specified, the value of the VERSION_CONTROL environment variable is used. And if VERSION_CONTROL is not set, the default backup type is `existing'. This option corresponds to the Emacs variable `version-control'; the same values for method are accepted as in Emacs. This options also more descriptive name. The valid methods (unique abbreviations are accepted):

`t'

`numbered'

Always make numbered backups.

`nil'

`existing'

Make numbered backups of files that already have them, simple backups of the others.

`never'

`simple'

Always make simple backups.