PowerShell equivalent to grep -f

Question

The -Pattern parameter in Select-String supports an array of patterns. So the one you're looking for is:

Get-Content .\doc.txt | Select-String -Pattern (Get-Content .\regex.txt)

This searches through the textfile doc.txt by using every regex(one per line) in regex.txt

PS) new-alias grep findstr
PS) C:\WINDOWS> ls | grep -I -N exe

105:-a---        2006-11-02     13:34      49680 twunk_16.exe
106:-a---        2006-11-02     13:34      31232 twunk_32.exe
109:-a---        2006-09-18     23:43     256192 winhelp.exe
110:-a---        2006-11-02     10:45       9216 winhlp32.exe

PS) grep /?

I'm not familiar with grep but with Select-String you can do:

Get-ChildItem filename.txt | Select-String -Pattern <regexPattern>

You can also do that with Get-Content:

(Get-Content filename.txt) -match 'pattern'

So I found a pretty good answer at this link: https://www.thomasmaurer.ch/2011/03/powershell-search-for-string-or-grep-for-powershell/

But essentially it is:

Select-String -Path "C:\file\Path\*.txt" -Pattern "^Enter REGEX Here$"

This gives a directory file search (*or you can just specify a file) and a file-content search all in one line of PowerShell, very similar to grep. The output will be similar to:

doc.txt:31: Enter REGEX Here
HelloWorld.txt:13: Enter REGEX Here

I had the same issue trying to find text in files with powershell. I used the following - to stay as close to the Linux environment as possible.

Hopefully this helps somebody:

PowerShell:

PS) new-alias grep findstr
PS) ls -r *.txt | cat | grep "some random string"

Explanation:

ls       - lists all files
-r       - recursively (in all files and folders and subfolders)
*.txt    - only .txt files
|        - pipe the (ls) results to next command (cat)
cat      - show contents of files comming from (ls)
|        - pipe the (cat) results to next command (grep)
grep     - search contents from (cat) for "some random string" (alias to findstr)

Yes, this works as well:

PS) ls -r *.txt | cat | findstr "some random string"