Powershell：如果命令输出与预期的3个字符串数组不同，则发送电子邮件

Question

this is what i got so far

if the command places a forth line of output then the regex shouldn't be match, but it does for me.

any ideas?

$From = "cody@tech.com"
$To = "cody@tech.com"
$Subject = "hello"
$Body = "body"
$SMTPServer = "smtp.office365.com"
$SMTPPort = "587"
$Attachment = "c:\checkpointlog.txt"

$RE = [regex]"(?smi)^Checkpointing to checkpoint.*^MD5 \(checkpoint.*^Rotating D:\\Perforce\\Server\\journal to journal.*?$"

$output = p4d -jc
$output | add-content c:\checkpointlog.txt

if ($output -notmatch $RE) { 
    $param = @{
        From        = $From
        To          = $To
        Subject     = $Subject
        Body        = $Body 
        SmtpServer  = $SMTPServer 
        port        = $SMTPPort 
        Usessl      = $True
        Credential  = $cred 
        Attachments = $Attachment
    }
    Send-MailMessage @param
    Write-Host 'unexpected value, email sent' 
    exit
}
else {
Write-Host 'continuing script' 

}

the output of a Perforce Helix Server command p4 -jc should always be like the following 3 lines:

Checkpointing to checkpoint.22... 
MD5 (checkpoint.22) = F561234wer2B8E5123456767745645616D 
Rotating D:\Perforce\Server\journal to journal.21...

I would like to use a regex in an if statement so that if the output doesn't match the 3 line string below then an email is sent with the log file for us to inspect.

Checkpointing to checkpoint.*
MD5 (checkpoint.*
Rotating D:\Perforce\Server\journal to journal.*

I am hoping to use a wild card * to account for the incremental number

Any ideas would be great!

Answer 1

• Your regex tries to match multiple lines , and therefore needs a single multi-line string as input .

• Capturing an external program's output returns an array of strings (lines) .

• Using an array of string as the LHS of the -match operator causes PowerShell to match the regex against each string individually .

Therefore, join the lines output by p4d with newlines to form a single multi-line string , so that your regex can match multiple lines:

$output = (p4d -jc) -join "`n"

---

Additionally, if you want to make sure that your regex matches the entire input, not just a substring , restructure you regex as follows:

• Remove in-line option m (multi-line) so that ^ and $ truly only match the very start and end of the multi-line string

• Remove in-line option s , so that . doesn't match newlines, and match newlines explicitly with \\n (instead of ^ ).

$RE = '(?i)^Checkpointing to checkpoint.*\nMD5 \(checkpoint.*\nRotating D:\\Perforce\\Server\\journal to journal.*$'

Answer 2

• Build (and test) your Regular Expression on a website like regex101.com
• I suggest to use splatting

---

$RE = [regex]"(?smi)^Checkpointing to checkpoint.*^MD5 \(checkpoint.*^Rotating D:\\Perforce\\Server\\journal to journal.*?$"

$output = p4d -jc
$output | add-content c:\checkpointlog.txt

if ($output -notmatch $RE) { 
    $param = @{
        From        = $From
        To          = $To
        Subject     = $Subject
        Body        = $Body 
        SmtpServer  = $SMTPServer 
        port        = $SMTPPort 
        Usessl      = $True
        Credential  = $cred 
        Attachments = 'c:\checkpointlog.txt'
    }
    Send-MailMessage @param
    exit
}

Answer 3

I know you wanted to use RegEx but maybe this would help? It might not be the greatest but it should work.

$file='checkpointlog.txt'

$line1Expected="Checkpointing to checkpoint*"
$line2Expected="MD5 (checkpoint*"
$line3Expected="Rotating D:\Perforce\Server\journal to journal*"

$line1Actual=Get-Content($file) | Select -Index 0
$line2Actual=Get-Content($file) | Select -Index 1
$line3Actual=Get-Content($file) | Select -Index 2


if($line1Actual -like $line1Expected`
    -and $line2Actual -like $line2Expected`
    -and $line3Actual -like $line3Expected){
}else{
    echo 'send mail'
}