My code has the following function:
function status{
if ($args[0] -eq "Stopped"){
Write-Host -NoNewline "Stopped" -fore red
.....
}
}
and the function is used as:
...
Write-Host "$($count)) $($i.DisplayName) STATUS: $(status $i.State)"
...
The result after script execution is:
Stopped 1) XXXXXX STATUS:
Why "Stopped" is in the beginning of the line? can someone help me?
The function is only to change the text color. As the example -fore red is to Stopped value.
You could use ANSI Escape sequences for this but it wouldn't work in old terminals. I'm not convinced if this is possible combining outputs from Write-Host and, if it is, I'll assume is an extremely tedious task.
function status {
$ansi = switch($args[0]) {
Stopped { "$([char] 27)[91m" }
Running { "$([char] 27)[32m" }
}
$ansi + $args[0]
}
foreach($state in 'Running', 'Stopped') {
$count++
$i = [pscustomobject]@{ state = $state; displayname = 'Hello!' }
Write-Host "$($count)) $($i.DisplayName) STATUS: $(status $i.State)"
}
Which would produce the following output:
Santiago Squarzon's helpful answer provides an effective solution; let me complement it with an explanation of what you tried:
Why "Stopped" is in the beginning of the line?
The reason is that Write-Host doesn't write to PowerShell's success output stream and therefore doesn't "return" a value from your status function.
Instead, Write-Host instantly prints to the host (display; in PSv5+ via the information stream), before exiting the function, and your function produces no success-stream output.
Since subexpressions (via $(...)) are evaluated first in an expandable string (or command in general):
the Write-Host call inside your status function executes right away and prints at the start of the line.
only then does the outer Write-Host call execute, which - due to the inner call's -NoNewLine switch - prints on the same line, after what the function printed, and $(status $i.State), due to the status call producing no success output, evaluates to the empty string.
A simple example can illustrate the problem:
Write-Host "foo: >>$(Write-Host bar)<<"
Output:
bar # The inner Write-Host printed right away.
foo >><< # $(Write-Host bar) produced no success output
Santiago's solution avoids this problem by replacing the Write-Host call inside the function with sending a string (implicitly) to the success output stream, so that it becomes the function's "return value" that subexpression $(status $i.State) expands to, and to make this string colored, ANSI / VT escape sequences are needed.
Note that while "$([char] 27)" is required in Windows PowerShell to embed an ESC character in an expanable string, PowerShell (Core) 7+ now offers escape sequence "`e"
Also, PowerShell (Core) 7.2+ offers the automatic $PSStyle variable, which, while more verbose, offers a more descriptive way to embed ANSI / VT escape sequences; e.g.:
# Prints only the word "green" in green.
"It ain't easy being $($PSStyle.Foreground.Green)green$($PSStyle.Reset)."
Note:
If you send strings with ANSI / VT sequences to the success output stream, as in the example above, colors are not automatically reset; $PSStyle.Reset is needed for a manual reset.
By contrast, if Write-Host prints a string, it resets colors automatically.
