Display entire error message from logfile using powershell - powershell

Question

One of the batch scripts creates a logfile and it can have error messages like as below
Msg 2714, Level 16, State 1:
Server 'ABC', Procedure 'proc_test1', Line 189:
There is already an object named 'table_test' in the database.
Msg 207, Level 16, State 4:
Server 'ABC', Procedure 'proc_test2', Line 197:
Invalid column name 'employee'.
Msg 207, Level 16, State 4:
Server 'ABC', Procedure 'proc_test2', Line 197:
Invalid column name 'address'.
Using a powershell script to read and report errors to a mail from the log file. And i'm using this, which excludes certain warning messages too.
Select-String -Path 'C:\Users\BatchLog_20200911.txt' -Pattern "Msg","Error" | Select-String -Pattern "SQLState = S1000, NativeError = 0" -notmatch | select-object -Property Line,LineNumber
Output is as below
Line LineNumber
---- ----------
Msg 2714, Level 16, State 1: 2791
Msg 207, Level 16, State 4: 2794
Msg 207, Level 16, State 4: 2797
CT-LIBRARY error: 2828
ct_results(): network packet layer: internal net library error: Net-Library operation terminated due to disconnect 2829
"Errors encountered during execution. Exited with status: 596" 4168
So, it just prints line which match the query. I want to print the next lines which has actual error message description. Any advise here. Thanks.

Answer 1

Use the -Context parameter of the Select-String cmdlet:
Select-String -Path 'C:\Users\BatchLog_20200911.txt' "Msg","Error" -Context 0,1 |
ForEach-Object {
if ($_.Context.PostContext[0] -notmatch 'SQLState = S1000, NativeError = 0') {
[pscustomobject] #{
Line = $_.Context.PostContext[0]
LineNumber = $_.LineNumber
}
}
}
-Context 0,1 captures 0 lines before and 1 line after along with the actually matching line.
In the resulting Microsoft.PowerShell.Commands.MatchInfo instance, .Context.PostContext[0] provides access to the first post-context (after) line.
With your sample input, the above yields:
Line LineNumber
---- ----------
Server 'ABC', Procedure 'proc_test1', Line 189: 1
Server 'ABC', Procedure 'proc_test2', Line 197: 4
Server 'ABC', Procedure 'proc_test2', Line 197: 7