|Purpose:||Search for and optionally delete or symlink duplicated files.|
|Format:||DEDUPE [ranges] [/= /A:[[-|+]rhsadecijopt /D /H /L /N[defjnstz] /P /Q /R /S[[+]n] /SHA1 /SHA256 /SHA384 /SHA512 /T /V /W[n]] filename directory [directory...]|
|filename||The filename to search for (* for everything)|
|directory||The directories (and optionally subdirectories) to search|
File Completion Syntax:
The default filename completion syntax is:  * [2*] dirs
DEDUPE searches one or more directories, assigns a hash value to files, and then compares the hash value to all the other files. On slow systems (and particularly in x86 Windows) this can take a while, so you should try to reduce the amount of searching & hashing by using ranges, and not try to dedupe an entire disk at one time.
DEDUPE assumes that the first file it finds for each hash is the original file.
|/=||Display the DEDUPE command dialog to help you set the filename and command line options. The /= option can be anywhere on the line; additional options will set the appropriate fields in the command dialog.|
|/A:||Dedupe those files that have the specified attribute(s) set. See Attribute Switches for information on the attributes which can follow /A:. Do not use /A: with @file lists. See @file lists for details.|
You can specify /A:= to display a dialog to help you set individual attributes.
|/L||Convert duplicate files to symlinks of the first file. Note that to create symlinks, you must be in an elevated session.|
|d||Skip hidden directories (when used with /S)|
|e||Don't display errors|
|f||Don't display the bytes freed in the summary|
|j||Skip junctions (when used with /S)|
|s||Don't display the summary|
|t||Don't update the CD / CDD extended directory search database (JPSTREE.IDX)|
|z||Skip system directories (when used with /S)|
|/SHAx||Hash algorithm to use. The default is SHA256; you can optionally use SHA1 or SHA512. SHA1 is slightly faster but potentially insecure.|