What does %~dp0 mean, and how does it work?

I find `%~dp0` very useful, and I use it a lot to make my batch files more portable.

But the label itself seems very cryptic to me... What is the `~` doing? Does `dp` mean drive and path? Does the `0` refer to `%0`, the path to the batch file that includes the file name?

Or it is just a weird label?

I'd also like to know if it is a documented feature, or something prone to be deprecated.

Great example from Strawberry Perl's portable shell launcher:


set drive=%~dp0
set drivep=%drive%
if #%drive:~-1%# == #\# set drivep=%drive:~0,-1%

set PATH=%drivep%\perl\site\bin;%drivep%\perl\bin;%drivep%\c\bin;%PATH%

not sure what the negative 1's doing there myself, but it works a treat!

Another tip that would help a lot is that to set the current directory to a **different drive** one would have to use **`%~d0`** first, then **`cd %~dp0`**. This will change the directory to the batch file's drive, then change to its folder.

Alternatively, for #oneLinerLovers, as @Omni pointed out in the comments **`cd /d %~dp0`** will change both the drive and directory :)

Hope this helps someone.

An example would be nice - here's a trivial one

for %I in (*.*) do @echo %~xI

it lists only the EXTENSIONS of each file in current folder

for more useful variable combinations (also listed in previous response) from the CMD prompt execute: `HELP FOR`
which contains this snippet

The modifiers can be combined to get compound results:

%~dpI - expands %I to a drive letter and path only
%~nxI - expands %I to a file name and extension only
%~fsI - expands %I to a full path name with short names only
%~dp$PATH:I - searches the directories listed in the PATH
environment variable for %I and expands to the
drive letter and path of the first one found.
%~ftzaI - expands %I to a DIR like output line

%~dp0 expands to current directory path of the running batch file.

To get clear understanding, let's create a batch file in a directory.

> C:\script\test.bat

with contents:

@echo off
echo %~dp0

When you run it from command prompt, you will see this result:

> C:\script\

Calling

for /?

in the command-line gives help about this syntax (which can be used outside FOR, too, this is just the place where help can be found).

> In addition, substitution of FOR
> variable references has been enhanced.
> You can now use the following optional
> syntax:
>
> %~I - expands %I removing any surrounding quotes (")
> %~fI - expands %I to a fully qualified path name
> %~dI - expands %I to a drive letter only
> %~pI - expands %I to a path only
> %~nI - expands %I to a file name only
> %~xI - expands %I to a file extension only
> %~sI - expanded path contains short names only
> %~aI - expands %I to file attributes of file
> %~tI - expands %I to date/time of file
> %~zI - expands %I to size of file
> %~$PATH:I - searches the directories listed in the PATH
> environment variable and expands %I to the
> fully qualified name of the first one found.
> If the environment variable name is not
> defined or the file is not found by the
> search, then this modifier expands to the
> empty string
>
> The modifiers can be combined to get
> compound results:
>
> %~dpI - expands %I to a drive letter and path only
> %~nxI - expands %I to a file name and extension only
> %~fsI - expands %I to a full path name with short names only
> %~dp$PATH:I - searches the directories listed in the PATH
> environment variable for %I and expands to the
> drive letter and path of the first one found.
> %~ftzaI - expands %I to a DIR like output line
>
> In the above examples %I and PATH can
> be replaced by other valid values.
> The %~ syntax is terminated by a valid
> FOR variable name. Picking upper case
> variable names like %I makes it more
> readable and avoids confusion with the
> modifiers, which are not case
> sensitive.

There are different letters you can use like `f` for "full path name", `d` for drive letter, `p` for path, and they can be combined. `%~` is the beginning for each of those sequences and a number `I` denotes it works on the parameter `%I` (where `%0` is the complete name of the batch file, just like you assumed).

The variable `%0` in a batch script is set to the name of the executing batch file.

The `~dp` special syntax between the `%` and the `0` basically says to expand the variable `%0` to show the drive letter and path, which gives you the current directory containing the batch file!

Help = [Link][1]


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(First, I'd like to recommend this useful reference site for batch:

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)


Then just another useful explanation:

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> # The %~dp0 Variable #
>
> The `%~dp0` (that’s a zero) variable when referenced within a Windows
> batch file will expand to the **d**rive letter and **p**ath of that batch
> file.
>
> The variables `%0-%9` refer to the command line parameters of the batch
> file. `%1-%9` refer to command line arguments after the batch file name.
> `%0` refers to the batch file itself.
>
> If you follow the percent character (`%`) with a tilde character (`~`),
> you can insert a modifier(s) before the parameter number to alter the
> way the variable is expanded. The `d` modifier expands to the drive
> letter and the `p` modifier expands to the path of the parameter.
>
> Example: Let’s say you have a directory on `C:` called `bat_files`, and
> in that directory is a file called `example.bat`. In this case, `%~dp0`
> (combining the `d` and `p` modifiers) will expand to `C:\bat_files\`.
>
> Check out [this Microsoft article][1] for a full explanation.
>
> Also, check out [this forum thread][2].


And a more clear reference from [here][3]:

- `%CmdCmdLine%` will return the entire command line as passed to CMD.EXE

- `%*` will return the remainder of the command line starting at the first command line argument (in Windows NT 4, %* also includes all leading spaces)

- `%~dn` will return the drive letter of %n (n can range from 0 to 9) if %n is a valid path or file name (no UNC)

- `%~pn` will return the directory of %n if %n is a valid path or file name (no UNC)

- `%~nn` will return the file name only of %n if %n is a valid file name

- `%~xn` will return the file extension only of %n if %n is a valid file name

- `%~fn` will return the fully qualified path of %n if %n is a valid file name or directory

ADD 1
---
Just found some good reference for the *mysterious* `~` tilde operator.

The `%~` string is called [percent tilde][4] operator. You can find it in situations like: `%~0`.

The `:~` string is called [colon tilde][5] operator. You can find it like `%SOME_VAR:~0,-1%`.

ADD 2 - 1:12 PM 7/6/2018
---
`%1-%9` refer to the command line args. If they are **not** valid path values, `%~dp1` - `%~dp9` will all expand to the same value as `%~dp0`. But if they **are** valid path values, they will expand to **their own** driver/path value.

For example:
(batch.bat)

@echo off
@echo ~dp0= %~dp0
@echo ~dp1= %~dp1
@echo ~dp2= %~dp2
@echo on

Run 1:

D:\Workbench>batch arg1 arg2

~dp0= D:\Workbench\
~dp1= D:\Workbench\
~dp2= D:\Workbench\

Run 2:

D:\Workbench>batch c:\123\a.exe e:\abc\b.exe

~dp0= D:\Workbench\
~dp1= c:\123\
~dp2= e:\abc\

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