Powershell Search a pattern string in two lines together

Question

I am trying to search two strings in any two consecutive lines and need help.

Two search strings are "Airport" and "Rate" and sample Input file is described below :

Content of Input file :

1. Airport
2. Rate
3. Some text
4. Some more text
5. Airport
6. Some text

Desired Output :

1. Airport
2. Rate

P.S. Airport keyword in 5. is not in desired output since 4. and 6. doesn't have Rate keyword.

This is how I have get it so far :

PS> get-content "c:\Inputfile.txt" | select-string "Airport" -context 1 | s
elect-string "Rate" > c:\airportrate.txt


Thanks.

Answer 1

Using V3:

$Text = Get-Content "c:\Inputfile.txt" -Raw
[regex]$regex = '(?m)(^\d+\.\sAirport.*?\n\d+\.\sRate.*?)'
$regex.Matches($Text).value

From get-help get-content (V3)

-Raw Ignores newline characters and returns the entire contents of a file in one string. By default, the contents of a file is returned as a array of strings that is delimited by the newline character.

Raw is a dynamic parameter that the FileSystem provider adds to the Get-Content cmdlet. This parameter works only in file system drives.

This parameter is introduced in Windows PowerShell 3.0.

Answer 2

Try something like this, I've tested this on your input and got the correct output.

$reader = [System.IO.File]::OpenText("c:\Inputfile.txt")
$prevLine = ""
try {
    for(;;) {
        $line = $reader.ReadLine()
        if ($prevLine -ne "") 
        {
            if ($line -Match "Rate") 
            { 
                if ($prevLine -Match "Airport")
                {
                    $prevLine
                    $line
                }
            }                
        }
        $prevLine = $line
    }
}
finally {
    $reader.Close()
}

Credit due: https://stackoverflow.com/a/4192419/770270

Answer 3

Read the file content in chunks of two lines, cast each chunk to a string and test if it matches your criteria:

PS> Get-Content .\lines.txt -ReadCount 2 | Where-Object {"$_" -match 'Airport.*rate' }
1. Airport
2. Rate