Is it possible to count specific strings in a file and save the value in a variable?
For me it would be the String "/export" (without quotes).
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5 Answers
Here's one method:
$FileContent = Get-Content "YourFile.txt"
$Matches = Select-String -InputObject $FileContent -Pattern "/export" -AllMatches
$Matches.Matches.Count
6 Comments
akhansari
one liner :
(Select-String -Path "YourFile.txt" -Pattern "/export" -AllMatches).Matches.Count
NealWalters
Gives "Out of Memory" on very large files, might need to use a streaming technique if working with huge files.
Bennett McElwee
@NealWalters Do you have any more information on a streaming technique? I need to count occurrences of a string in a 6GB file: I expect about 5 million occurrences.
NealWalters
@BennettMcElwee - I can't remember now if I solved it or not.
Bennett McElwee
@NealWalters I'll take that as a no :-) But thanks - I used your idea to come up with a solution that solved my problem.
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Here's a way to do it.
$count = (get-content file1.txt | select-string -pattern "/export").length
As mentioned in comments, this will return the count of lines containing the pattern, so if any line has more than one instance of the pattern, the count won't be correct.
4 Comments
Allen Z.
This returns the number of lines containing the string, not the total number of matches.
Knox
Can confirm what @AllenZ. says
Leon Bambrick
Agreed. I've added a note on it to the answer. Decided not to delete my answer, as it's often a useful approach.
VinyJones
Please at lease put in bold "the count won't be correct"
If you're searching in a large file (several gigabytes) that could have have millions of matches, you might run into memory problems. You can do something like this (inspired by a suggestion from NealWalters):
Select-String -Path YourFile.txt -Pattern '/export' -SimpleMatch | Measure-Object -Line
This is not perfect because
- it counts the number of lines that contain the match, not the total number of matches.
- it prints some headings along with the count, rather than putting just the count into a variable.
You can probably solve these if you need to. But at least you won't run out of memory.
Comments
The best solution I applied was
$count = (Select-String -Path "filepath" -Pattern "pattern" -AllMatches).Matches.Count
This one is memory optimized and accurate
Comments
grep -co vs grep -c
Both are useful and thanks for the "o" version. New one to me.
3 Comments
Phil
grep is not a thing in PowerShell.
Phil
my experience with powershell is use when you have to use whatever comes with windows. if you can install arbitrary packages, you can use something else entirely. certainly how to do x in y is not satisfactorily answered by install z