coreutils: Backup options
1
1 2.2 Backup options
1 ==================
1
1 Some GNU programs (at least ‘cp’, ‘install’, ‘ln’, and ‘mv’) optionally
1 make backups of files before writing new versions. These options
1 control the details of these backups. The options are also briefly
1 mentioned in the descriptions of the particular programs.
1
1 ‘-b’
1 ‘--backup[=METHOD]’
1 Make a backup of each file that would otherwise be overwritten or
1 removed. Without this option, the original versions are destroyed.
1 Use METHOD to determine the type of backups to make. When this
1 option is used but METHOD is not specified, then the value of the
1 ‘VERSION_CONTROL’ environment variable is used. And if
1 ‘VERSION_CONTROL’ is not set, the default backup type is
1 ‘existing’.
1
1 Note that the short form of this option, ‘-b’ does not accept any
1 argument. Using ‘-b’ is equivalent to using ‘--backup=existing’.
1
1 This option corresponds to the Emacs variable ‘version-control’;
1 the values for METHOD are the same as those used in Emacs. This
1 option also accepts more descriptive names. The valid METHODs are
1 (unique abbreviations are accepted):
1
1 ‘none’
1 ‘off’
1 Never make backups.
1
1 ‘numbered’
1 ‘t’
1 Always make numbered backups.
1
1 ‘existing’
1 ‘nil’
1 Make numbered backups of files that already have them, simple
1 backups of the others.
1
1 ‘simple’
1 ‘never’
1 Always make simple backups. Please note ‘never’ is not to be
1 confused with ‘none’.
1
1 ‘-S SUFFIX’
1 ‘--suffix=SUFFIX’
1 Append SUFFIX to each backup file made with ‘-b’. If this option
1 is not specified, the value of the ‘SIMPLE_BACKUP_SUFFIX’
1 environment variable is used. And if ‘SIMPLE_BACKUP_SUFFIX’ is not
1 set, the default is ‘~’, just as in Emacs.
1