What does dp0 mean and how does it work

Question

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

User · Answer

First  I d like to recommend this useful reference site for batch  http   ss64 com nt   Then just another useful explanation  http   htipe wordpress com 2008 10 09 the-dp0-variable   The   dp0 Variable The   dp0  that   s a zero  variable when referenced within a Windows batch file will expand to the drive letter and path 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 for a full explanation  Also  check out this forum thread   And a more clear reference from here    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 operator  You can find it in situations like    0  The    string is called colon tilde 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 gt batch arg1 arg2   dp0  D  Workbench   dp1  D  Workbench   dp2  D  Workbench   Run 2  D  Workbench gt batch c  123 a exe e  abc b exe   dp0  D  Workbench   dp1  c  123   dp2  e  abc

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

[batch-file] What does %~dp0 mean, and how does it work?

The %~dp0 Variable

ADD 1

ADD 2 - 1:12 PM 7/6/2018

Examples related to batch-file