PowerShell equivalent to grep -f

Question

I'm looking for the PowerShell equivalent to grep --file=filename. If you don't know grep, filename is a text file where each line has a regular expression pattern you want to match.

Maybe I'm missing something obvious, but Select-String doesn't seem to have this option.

Solution 1

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

Solution 2

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 /?

Solution 3

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'

Solution 4

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"

Solution 5

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

View more solutions

Comments

[joon]

Also, PowerShell tab completion will make commands properly capitalized, so it is not hard to input.

[Jeroen]

Extended this to e.g. dir *.cs -Recurse | sls "TODO" | select -Unique "Path". Thx for the excellent pointer.

[Frode F.]

I never understood how this got so many votes. It's doesn't even answer the question..

[Elijah W. Gagne]

What I like about this answer is that findstr works the most like grep on Linux does. Select-String is great for working with objects, but sometimes you just want to match on strings.

[dee-see]

@joon A couple of years late, but I'd add that Powershell is case insensitive so the capitalization of commands is not an issue.

[joon]

@Vache of course - I think my comment above is a reply to another comment, but it seems the comment is gone anymore.

[anishpatel]

It is worth noting that findstr is not native to PowerShell, but Command Prompt.

[Rag]

He wants to load the pattern from a file.

[Lennon]

This findstr command was already available to me, and it worked just like unix GREP.

[Kellen Stuart]

This is a bad answer. Select-String -Pattern somestring is much cleaner

[cody.tv.weber]

If that is what he is asking, there are other answers that are similar to mine, so I feel like the question may not be worded super clear of desired answer. But after rereading it, I agree that he probably is wanting to pipe regex from a file into select string.

[Ken Seehart]

That's pretty good, but I also want the name of the file where it was found

[pixis]

@dee-see A couple of years late, but I'd add that Windows is case insensitive so the capitalization of commands, paths,... is not an issue. :)

[skaveesh]

@FrodeF. that's because this question is the first thing comes up when we search for "powershell grep equivalent". :)

[ruffin]

Worth mentioning that -I is "insensitive" and -N includes the line number, and that in Windows you'd normally use /i and /n. Also note that the /r option for regex is on by default. All parameters for findstr are currently described here. As best as I can tell, you use find (no str) to avoid regular expressions.

[рüффп]

Good to know the alias is sls which is faster to write

[Dan]

Select-String isn't very good at doing line-based context, which grep is great at.