file rename

: file rename ?-force? ?--? source target
: file rename ?-force? ?--? source ?source ...? targetDir

The first form takes the file or directory specified by pathname source and renames it to target, moving the file if the pathname target specifies a name in a different directory. If target is an existing directory, then the second form is used. The second form moves each source file or directory into the directory targetDir. Existing files will not be overwritten unless the -force option is specified. When operating inside a single filesystem, Tcl will rename symbolic links rather than the things that they point to. Trying to overwrite a non-empty directory, overwrite a directory with a file, or a file with a directory will all result in errors. Arguments are processed in the order specified, halting at the first error, if any. A -- marks the end of switches; the argument following the -- will be treated as a source even if it starts with a -.

jmn 2008-07-11 On windows, check your version of Tcl is not subject to bug 2015723 [1] regarding file rename -force

I'm only annotating certain wiki pages with a pointer to this bug because it is a silent intermittent failure that may go undetected.

LV So, what kind of code would one need to take a directory of file names and rename them using regular expressions? For instance, say I wanted to remove spaces from files in a directory.

HJG Here is a piece of working code to replace spaces with underscores in filenames:

  set files [glob {*.*}]
  foreach fname1 $files {
    if { [string first " " $fname1] >= 0 } {
      set fname2 [regsub -all " " $fname1 "_"]
     #puts "rename '$fname1' to '$fname2'" 
      file rename -force -- $fname1 $fname2   ;# ! overwrites existing files !
    }
  }

However, to do the above generically, so that a general old and new pattern could be passed and observed, that would be more difficult I suppose. If this code could be generically written, it would make a nice addition to fileutil.

Another useful application would be Rename and redate photo-files, i.e. from a digital camera, according to date and time.

bll 2015-2-18 Windows has filenames that preserve case, but are not distinguished by case. So both 'type xyzzy' and 'type XYZZY' will work no matter what case 'xyzzy' has. If you wish to change the filename's case using file rename, you must use "file rename -force", as file rename's check to see if the file exists will be true, as both 'xyzzy' and 'XYZZY' point to the same file.

See also edit