Question

myprogram.cmd is in PATH;

myprogram.cmd uses %~dp0 to determine the folder it is in;

I have included @echo %~dp0 into myprogram.cmd for debugging;

When I call myprogram.cmd from anywhere, it works perfectly, displaying the folder myprogram.cmd is in;

When I call hg extdiff -p myprogram.cmd, it does not work, displaying something like c:\Users\Username\AppData\Local\Temp\extdiff.3n8op2\.

Here is the related part of hgrc file:

[extensions]
hgext.extdiff = 

What do I do wrong? Should not %~dp0 return drive and path of the batch file? What do I use instead? Do I have to apply some special configuration to Mercurial repository? Passing the full path of myprogram.cmd to hg extdiff -p is not an option, unless it is done automatically.

Answer 1

You can try using %~dp$PATH:0, but you need to always specify the extension. For example, for the following test.cmd:

rem test.cmd
@echo dp0 == %~dp0
@echo dp$PATH:0 == %~dp$PATH:0

these are two sample runs from the d:\hg folder:

$ hg extdiff -p test.cmd
dp0 == c:\Users\estefan\AppData\Local\Temp\extdiff.pamj6n\
dp$PATH:0 == k:\home\Scripts\

$ hg extdiff -p test
dp0 == c:\Users\estefan\AppData\Local\Temp\extdiff.dgp0qz\
dp$PATH:0 ==

From http://ss64.com/nt/syntax-args.html:

%~$PATH:1 Search the PATH environment variable and expand %1 to the fully qualified name of the first match found.