CODEWITHSUNDEEP
powershellpowershell-3.0
user746461
user746461

Reputation:

PowerShell: select string in standard output?

PS C:\squid\sbin> .\squid.exe -v
Squid Cache: Version 2.7.STABLE8
configure options: --enable-win32-service --enable-storeio='ufs aufs null coss' --enable-default-hostsfile=none --enable
-removal-policies='heap lru' --enable-snmp --enable-htcp --disable-wccp --disable-wccpv2 --enable-useragent-log --enable
-referer-log --enable-cache-digests --enable-auth='basic ntlm digest negotiate' --enable-basic-auth-helpers='LDAP NCSA m
swin_sspi squid_radius_auth' --enable-negotiate-auth-helpers=mswin_sspi --enable-ntlm-auth-helpers='mswin_sspi fakeauth'
 --enable-external-acl-helpers='mswin_ad_group mswin_lm_group ldap_group' --enable-large-cache-files --enable-digest-aut
h-helpers='password LDAP eDirectory' --enable-forw-via-db --enable-follow-x-forwarded-for --enable-arp-acl --prefix=c:/s
quid
Compiled as Windows System Service.
PS C:\squid\sbin> .\squid.exe -v|Select-String Squid

squid.exe -v will output its version information, which contains keyword "Squid".

I want powershell to tell me whether keyword "Squid" exists in the output. So I use .\squid.exe -v|Select-String Squid, but it outputs nothing.

What's the right way to do it? I'm using PS 3.0.

Upvotes: 2

Views: 1433

Answers (1)

Andy Arismendi
Andy Arismendi

Reputation: 52577

You ARE doing it the right way :)

The problem is not your code but the squid port itself. Its doing something weird to write text to the console to where PowerShell and cmd can't capture it through the stdout/stderr streams. I'm guessing instead of using the stdout/stderr api it may be manipulating characters on the console directly or something. I tried redirecting stderr to stdout (2>&1) but that didn't work either.

It comes with a change log text file, I guess you can just parse that instead...

EDIT --

Or you can use this kludgy but serviceable workaround to scrape the console text:

function Get-ConsoleText {
    if ($host.Name -eq 'ConsoleHost') { 
        $text_builder = new-object system.text.stringbuilder 
        $buffer_width = $host.ui.rawui.BufferSize.Width 
        $buffer_height = $host.ui.rawui.CursorPosition.Y 
        $rec = new-object System.Management.Automation.Host.Rectangle 0,0,($buffer_width -2), $buffer_height
        $buffer = $host.ui.rawui.GetBufferContents($rec) 

        $console_out = @()
        for($i = 0; $i -lt $buffer_height; $i++) { 
            $text_builder = new-object system.text.stringbuilder 
            for($j = 0; $j -lt $buffer_width; $j++) { 
                $cell = $buffer[$i,$j] 
                $text_builder.Append($cell.Character) | Out-Null
            }
            $console_out += $text_builder.ToString()
        } 
        return $console_out
    } 
}

cls; .\squid.exe -v; Get-ConsoleText | 
    ForEach-Object {
        if ($_ -match 'Version (.+)') {$matches[1]}
    }

Upvotes: 2

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