CODEWITHSUNDEEP
variablesbatch-filesubstringexpansion
David De Weerdt
David De Weerdt

Reputation: 33

batch files, variable expansion and substrings in loops

I can't wrap my head around the variable substitution mechanism of DOS batch files, especially in for loops.

Simplified batch problem: imagine the following directory
01foo.txt
02foo.dir (this is a directory)
bar01 (this is a directory)
bar02 (this is a directory)

i want to move all files/directories in this directory that do NOT start with 'bar' to a subdirectory that is bar+_the_first_2_characters_of_the_filename_or_directory_name.
In this case, 01foo.txt would be moved into bar01 and 02foo.dir would be moved into bar02.

The following script is my first attempt: 

setlocal EnableDelayedExpansion  
for %%A in (*) do (  
    set _x=%%A
    if (!_x:~0,2! NEQ "bar") move %%A bar!_x:~0,2!
)
endlocal

apart from the fact that this seems to loop only for files, it simply doesn't work at all :-). I get an error in the if statement saying "3! was unexpected at this time"

Any idea on how to improve the situation/script?

Thanks

Upvotes: 1

Views: 1898

Answers (1)

jeb
jeb

Reputation: 82337

It's only a problem of the syntax...

The IF statement does not expect not accept surrounding brackets.
The the comma in !_x:~0,2! breaks the IF-statment, you could quote both parts or move it into an own set prefix=!_x:~0,2!" line.
If you quote "bar" you also need to quote "!prefix!".

That's all

setlocal EnableDelayedExpansion  
for %%A in (*) do (  
    set "_x=%%A"
    set "prefix=!_x:~0,2!"
    if "!prefix!" NEQ "bar" move %%A bar!prefix!
)
endlocal

Upvotes: 2

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