Powershell - Select a specific word from text - powershell

Question

I'm still very much learning Powershell and I'm a bit lost regarding a command to use.
I have this
docker login -u AWS -p PASSWORD -e none number.dkr.ecr.REGION.amazonaws.com
and I want to select PASSWORD.
Ideally, I would like this PASSWORD to get into a file, and use it after (but that I can do).
I am lost on what command to use. I know awk '{print $6}' would work but I need the powershell as I'm using a windows machine.
I know it's a really simple question, I have been reading answers, but I am just confused by the different parameters, and the different ways by different people and well, Powershell is wonderful but I'm still learning.
Thanks a lot!!

Answer 1

The default field separator(s) in awk is whitespace, so we can do the same in PowerShell and then grab the 6th resulting substring.
For this, we can use the -split regex operator - it supports the following syntaxes:
[strings] -split [pattern]
or
-split [strings]
When used as in the second example above, it defaults to splitting on whitespace just like awk:
-split "docker login -u AWS -p PASSWORD -e none number.dkr.ecr.REGION.amazonaws.com"
If we wrap the expression in #(), we can index into it:
$Password = #(
-split "docker login -u AWS -p PASSWORD -e none number.dkr.ecr.REGION.amazonaws.com"
)[5]
or we can use the Select-Object cmdlet to grab it:
$Password = -split "docker login -u AWS -p PASSWORD -e none number.dkr.ecr.REGION.amazonaws.com" |Select-Object -Index 5
If, however, we always want to grab the substring immediately after -p instead of whatever the 6th string is, we could use the -replace regex operator instead:
$string = "docker login -u AWS -p PASSWORD -e none number.dkr.ecr.REGION.amazonaws.com"
$string -replace '^.*-p\s+(\S+).*$','$1'

Answer 2

You can make this more complex :) I just used simple regexp, but you can make it better :)
$x = "docker login -u AWS -p PApSSWORD -e none number.dkr.ecr.REGION.amazonaws.com "
$x -match "(\-p[a-z0-9 ]*\-e)"
$matches[1] -replace '(\-p) ([a-z0-9 ]*) (\-e)' , ' $2'

Answer 3

Another solution using a Regular Expression,
here with lookarounds
$string = 'docker login -u AWS -p PASSWORD -e none number.dkr.ecr.REGION.amazonaws.com'
if ($string -match '(?<=-p\s+).*(?=\s+-e)'){
$Password = $Matches.Value
} else {
"No password found"
}