Is it possible to use a ternary operator inside a pipeline?

Question

I wish to send file and folder attributes to either a csv file or to the screen depending on the boolean value of $debug. I have tried to accomplish this by including a ternary operator in the end of the following pipeline:

Get-ChildItem $directory -Recurse -File |
    Select-Object @{name='Folder_Name';expression={$($_.directoryname)}},
                  @{name='File_type';expression={$($_.extension)}},
                  @{name='File_name';expression={$($_.name)}},
                  @{name='File_size_bytes';expression={$($_.length)}},
                  @{name='Creation_datetime';expression={$($_.creationtime)}},
                  @{name='Last_update_datetime';expression={$($_.lastwritetime)}},
                  @{name='Last_read_datetime';expression={$($_.lastaccesstime)}} |
                  (&{if ($debug) {Write-Host} else {Export-Csv -path $outpath -NoTypeInformation -force -Delimiter ';'}})

Is this a bad approach, and which approach is recommended?

Answer 1

this will do what you seem to want. however, it is a REALLY strange way to handle the problem. it is SLOW since it does a file write for every item OR a screen write for each item if that is enabled. saving to a $Var and then writing to file and/or screen would be much faster. [grin]

this code expands your last line into a ForEach-Object call with an if to test the output destination. it also adds an -ErrorAction to the Get-ChildItem call to handle "inaccessible file" errors.

it also removes the unneeded $() in the expression = lines.

$directory = $env:TEMP
$outpath = "$env:TEMP\GustavRasmussen.csv"

# uncomment the 2nd line to test the negative
$ToScreen = $True
#$ToScreen = $False

Get-ChildItem $directory -Recurse -File -ErrorAction SilentlyContinue |
    Select-Object @{name='Folder_Name';expression={$_.directoryname}},
                  @{name='File_type';expression={$_.extension}},
                  @{name='File_name';expression={$_.name}},
                  @{name='File_size_bytes';expression={$_.length}},
                  @{name='Creation_datetime';expression={$_.creationtime}},
                  @{name='Last_update_datetime';expression={$_.lastwritetime}},
                  @{name='Last_read_datetime';expression={$_.lastaccesstime}} |
    ForEach-Object {
        if ($ToScreen)
            {
            $_
            }
            else
            {
            Export-Csv -InputObject $_ -path $outpath -NoTypeInformation -force -Delimiter ';' -Append
            }
        }

1st three lines of the CSV ...

"Folder_Name";"File_type";"File_name";"File_size_bytes";"Creation_datetime";"Last_update_datetime";"Last_read_datetime"
"C:\Temp";".tmp";"DELCD3A.tmp";"861968";"2019-07-13 11:43:18 PM";"2019-07-13 11:42:36 PM";"2019-07-13 11:43:18 PM"
"C:\Temp";".txt";"FXSAPIDebugLogFile.txt";"0";"2015-11-03 6:54:02 PM";"2015-11-03 6:54:02 PM";"2015-11-03 6:54:02 PM"
"C:\Temp";".log";"Genre-List_2019-10-01.log";"178";"2019-10-01 12:33:47 PM";"2019-10-01 12:33:47 PM";"2019-10-01 12:33:47 PM"

the 1st three items of the screen output ...

Folder_Name          : C:\Temp
File_type            : .tmp
File_name            : DELCD3A.tmp
File_size_bytes      : 861968
Creation_datetime    : 2019-07-13 11:43:18 PM
Last_update_datetime : 2019-07-13 11:42:36 PM
Last_read_datetime   : 2019-07-13 11:43:18 PM

Folder_Name          : C:\Temp
File_type            : .txt
File_name            : FXSAPIDebugLogFile.txt
File_size_bytes      : 0
Creation_datetime    : 2015-11-03 6:54:02 PM
Last_update_datetime : 2015-11-03 6:54:02 PM
Last_read_datetime   : 2015-11-03 6:54:02 PM

Folder_Name          : C:\Temp
File_type            : .log
File_name            : Genre-List_2019-10-01.log
File_size_bytes      : 178
Creation_datetime    : 2019-10-01 12:33:47 PM
Last_update_datetime : 2019-10-01 12:33:47 PM
Last_read_datetime   : 2019-10-01 12:33:47 PM