Variable argument in for loop changes depending on powershell command

Question

I was attempting to use powershell to run a program on all files of a given type within a folder.

I first did a test to see if I could loop through all file types in a folder, and wrote this up:

$files = ls *.inp
foreach ($file in $files) {echo $file.basename}

which output:

myfile1.inp
myfile2.inp
myfile3.inp

So far, so good. Now, when I put this next bit in a for loop, it didn't work:

$files = ls *.inp
foreach ($file in $files) {myProgram arg1=$file.basename}

Note that the path to myProgram is already part of my path variable, so I don't have to write the full path to myProgram.exe, I can just write myProgram. Also, arg1 = the file I want processed.

I wanted to see what was going on, so I echoed the above commands in the loop:

foreach ($file in $files) {echo myProgram arg1=$file.basename}

...which output:

myProgram arg1=myfile.inp.basename

So for some reason, the basename method isn't doing what I want it to in the second scenario.

I changed my script to the following, which works fine:

foreach ($file in $files) {echo myProgram arg1=$file}

My question is, why does $file.basename output different things in the two scenarios? If I only want to use the basename in the second situation, how would I do that?

Thanks!

zdan · Accepted Answer · 2013-09-16 17:48:01Z

1

The powershell parser see $file in this context (a tring argument) as a complete expression. So it executes $file and then appends ".basename" to that. To tell it to execute the entire string as a single expression you need to wrap it in $():

foreach ($file in $files) {myProgram arg1=$($file.basename)}

answered Sep 16, 2013 at 17:48

zdan

29.6k7 gold badges62 silver badges73 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Variable argument in for loop changes depending on powershell command

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related