What is an equivalent of *Nix 'cut' command in Powershell?

问题

I have following content in a configuration file (sample.cfg),

Time_Zone_Variance(Mins):300
Alert_Interval(Mins):2
Server:10.0.0.9
Port:1840

I'm trying to store an each values after the : by using split in PowerShell. but i'm not able to produce require output.

Can someone tell me how to use PowerShell split for the above problem ?

回答1:

You can read the contents of the file using Get-Content, then pipe each line through ForEach-Object, then use the split command on each line, taking the second item in the array as follows:

$filename = "sample.cfg"

Get-Content $filename | ForEach-Object {
    $_.split(":")[1]
}

Output

300
2
10.0.0.9
1840

Update

I prefer the approach by @AnsgarWiechers, but if you really need specifically named values you could create a hashtable and replace the name with the value:

$configValues = @{
    hour    = "Time_Zone_Variance(Mins)"
    min     = "Alert_Interval(Mins)"
    server  = "Server"
    port    = "Port"
}

Get-Content $filename | ForEach-Object {

    # Courtesy of Ansgar Wiechers
    $key, $value = $_ -split ':', 2

    foreach($configValuesKey in $($configValues.keys)) {
        if ($configValues[$configValuesKey] -eq $key)
        {
            $configValues[$configValuesKey] = $value
        }
    }
}

write-host "`nAll Values:"
$configValues
write-host "`nIndividual value:"
$configValues.port

Output

All Values:

Name                           Value                                                                                             
----                           -----                                                                                             
port                           1840                                                                                              
min                            2                                                                                                 
server                         10.0.0.9                                                                                          
hour                           300                                                                                               

Individual value:
1840

回答2:

I suppose you don't want to just split the lines, but actually create key/value pairs. That could be achieved like this:

$config = @{}
Get-Content 'C:\path\to\sample.cfg' | % {
  $key, $value = $_ -split ':', 2
  $config[$key] = $value
}

You could also use the ConvertFrom-StringData cmdlet:

Get-Content 'C:\path\to\sample.cfg' | % {
  ConvertFrom-StringData ($_ -replace ':','=')
}

The -replace operation is necessary, because ConvertFrom-StringData expects key and value to be separated by =. If you could change the delimiter in the config file from : to =, you could use ConvertFrom-StringData $_ without replacement.

回答3:

How's this?

function cut {
  param(
    [Parameter(ValueFromPipeline=$True)] [string]$inputobject,
    [string]$delimiter='\s+',
    [string[]]$field
  )

  process {
    if ($field -eq $null) { $inputobject -split $delimiter } else {
      ($inputobject -split $delimiter)[$field] }
  }
}


PS C:\> 'hi:there' | cut -f 0 -d :
hi

PS C:\> 'hi:there' | cut -f 1 -d :
there

PS C:\> 'hi:there' | cut -f 0,1 -d :
hi
there

PS C:\> 'hi:::there' | cut -f 0 -d :+
hi

PS C:\> 'hi   there' | cut
hi
there

回答4:

For a more succint syntax, this will also do the trick:

((Get-Content "your-file.txt") -Split ":")[1]

So the trick to use the -Split method is to have a String object returned by Get-Content (alias cat can also be used, actually), and from the resulting String[] object you can use the brackets to extract the n^th item.

Note: Using -Split without parenthesis around Get-Content won't work since -Split is not a parameter name for that command... 🤷‍♂️

来源：https://stackoverflow.com/questions/24634022/what-is-an-equivalent-of-nix-cut-command-in-powershell