


fileutil_traverse(n)      file utilities     fileutil_traverse(n)


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NAME
       fileutil_traverse - Iterative directory traversal

SYNOPSIS
       package require Tcl  8.3

       package require fileutil::traverse  ?0.4.1?

       package require fileutil

       package require control

       ::fileutil::traverse ?objectName? path ?option value...?

       $traverser command ?arg arg ...?

       $traverser files

       $traverser foreach filevar script

       $traverser next filevar

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DESCRIPTION
       This  package provides objects for the programmable traversal of direc-
       tory hierarchies.  The main command exported by the package is:

       ::fileutil::traverse ?objectName? path ?option value...?
              The command creates a new traversal object  with  an  associated
              global Tcl command whose name is objectName. This command may be
              used to invoke various operations  on  the  traverser.   If  the
              string  %AUTO% is used as the objectName then a unique name will
              be generated by the package itself.

              Regarding the recognized options see section OPTIONS. Note  that
              all  these  options  can  be set only during the creation of the
              traversal object. Changing them later is not possible and causes
              errors to be thrown if attempted.

              The object command has the following general form:

              $traverser command ?arg arg ...?
                     Command and its arguments determine the exact behavior of
                     the object.

       The following commands are possible for traversal objects:

       $traverser files
              This method is the most  highlevel  one  provided  by  traversal
              objects.  When invoked it returns a list containing the names of
              all files and directories matching the current configuration  of



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fileutil_traverse(n)      file utilities     fileutil_traverse(n)


              the traverser.

       $traverser foreach filevar script
              The  highlevel  files  method  (see above) is based on this mid-
              level method. When invoked it finds all  files  and  directories
              matching  per  the current configuration and executes the script
              for each path. The current path under consideration is stored in
              the  variable  named by filevar. Both variable and script live /
              are executed in the context of the caller of the method. In  the
              method  files  the  script simply saves the found paths into the
              list to return.

       $traverser next filevar
              This is the lowest possible interface to the traverser, the core
              all  higher  methods  are  built  on.  When invoked it returns a
              boolean value indicating whether it found a  path  matching  the
              current  configuration  (True),  or  not  (False). If a path was
              found it is stored into the variable named by  filevar,  in  the
              context  of  the  caller.   The foreach method simply calls this
              method in a loop until it returned False. This method is exposed
              so  that  we are also able to incrementally traverse a directory
              hierarchy in an event-based manner.


OPTIONS
       -prefilter command_prefix
              This callback is executed for directories. Its result determines
              if the traverser recurses into the directory or not. The default
              is to always recurse  into  all  directories.  The  callback  is
              invoked  with a single argument, the absolute path of the direc-
              tory, and has to return a boolean value, True when the directory
              passes the filter, and False if not.

       -filter command_prefix
              This  callback  is executed for all paths. Its result determines
              if the current path is a valid result, and returned by next. The
              default is to accept all paths as valid. The callback is invoked
              with a single argument, the absolute path to check, and  has  to
              return  a  boolean  value, True when the path passes the filter,
              and False if not.

       -errorcmd command_prefix
              This callback is executed for all paths the traverser has  trou-
              ble  with. Like being unable to change into them, get their sta-
              tus, etc. The default is to ignore any such problems. The  call-
              back  is  invoked  with  a  two arguments, the absolute path for
              which the error occured, and the error message. Errors thrown by
              the  filter  callbacks  are  handled  through this callback too.
              Errors thrown by the error callback itself are  not  caught  and
              ignored, but allowed to pass to the caller, i.e. however invoked
              the next. Any other results from the callback are ignored.






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fileutil_traverse(n)      file utilities     fileutil_traverse(n)


BUGS, IDEAS, FEEDBACK
       This document, and the package it describes, will  undoubtedly  contain
       bugs  and  other problems.  Please report such in the category fileutil
       of       the       Tcllib       SF       Trackers       [http://source-
       forge.net/tracker/?group_id=12883].   Please  also report any ideas for
       enhancements you may have for either package and/or documentation.

KEYWORDS
       directory traversal, traversal

CATEGORY
       Programming tools













































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