PowerShell Select-String

File and stream text search with Select-String — the PowerShell grep equivalent.

Select-String Quick Reference (PowerShell grep)

Basic pattern search

Select-String -Path *.log -Pattern "ERROR"
Select-String -Path *.log -Pattern "ERROR" -CaseSensitive

Recursive search

Get-ChildItem -Recurse -Filter *.adoc | Select-String -Pattern "hardcoded"

Context lines (like grep -A/-B/-C)

Select-String -Path auth.log -Pattern "Failed" -Context 2,3
# 2 lines before, 3 lines after

Extract matched value only

Get-Content log.txt | Select-String -Pattern '\d+\.\d+\.\d+\.\d+' -AllMatches |
    ForEach-Object { $_.Matches.Value } | Sort-Object -Unique

Multiple patterns

Select-String -Path *.log -Pattern "ERROR", "FATAL", "CRITICAL"

Invert match (like grep -v)

Select-String -Path config.txt -Pattern "^#" -NotMatch
# Lines NOT starting with #

Search with file filtering

Get-ChildItem -Recurse -Include *.ps1, *.psm1 |
    Select-String -Pattern "Invoke-Command" |
    Select-Object Path, LineNumber, Line

Pipe to object manipulation (the PowerShell advantage over grep)

Select-String -Path *.log -Pattern "Failed login from (?<ip>\d+\.\d+\.\d+\.\d+)" |
    ForEach-Object { $_.Matches.Groups['ip'].Value } |
    Group-Object | Sort-Object Count -Descending | Select-Object -First 10
# Top 10 source IPs for failed logins — structured, not text

PowerShell Select-String

Select-String Quick Reference (PowerShell grep)

See Also