Controlling column widths with Format-Table

Question

I am trying to get the last reboot time of some PCs from a list. When I use

foreach ($pc in $pclist) {
  Get-CimInstance -ClassName win32_operatingsystem -ComputerName $pc |
    select csname, lastbootuptime 
}

The output comes as following.

csname       lastbootuptime
------       --------------
CONFA7-L1-1A 7/15/2016 9:55:16 AM
CONFA7-L1-1F 5/31/2016 8:51:46 AM
CONFA7-L1-1G 6/18/2016 11:09:15 AM
CONFA7-L1... 6/26/2016 5:31:31 PM
CONFA7-L3... 7/24/2016 3:48:43 PM

Which is neat, but if the PC name is long, I am unable to see the full name. So I pipelined Format-Table:

Get-CimInstance -ClassName win32_operatingsystem -ComputerName $pc |
  select csname, lastbootuptime |
  Format-Table  -HideTableHeaders 

And this is what I get:

CONFA7-L1-1A 7/15/2016 9:55:16 AM



CONFA7-L1-1E 7/21/2016 12:58:16 PM



CONFA7-L1-1F 5/31/2016 8:51:46 AM

There are two problems here.

1. There is no heading. If I remove -HideTableHeaders there will be heading for every output which is not required.

2. There is a lot of white spaces in between.

Basically I just need to get an output similar to the first one, but without truncating the full names. How can I fix these?

Answer 1

If you want trim data past a certain length and manually specify column widths, you can pass a Width property for each property attribute.

For example, if you wanted your data to look like this:

Column 1    Column 2      Column 3      Column 4
--------    --------      --------      --------
Data        Lorem ip...   Lorem ip...   Important data

Here's the basic Format-Table syntax, with a list of explicit properties:

$data | Format-Table -Property Col1, Col2, Col3, Col4 -AutoSize

Instead of just passing in the property names, we can add some additional metadata to Property:

$a = @{Expression={$_.Col1}; Label="Column 1"; Width=30}, 
     @{Expression={$_.Col2}; Label="Column 2"; Width=30}, 
     @{Expression={$_.Col3}; Label="Column 3"; Width=30}, 
     @{Expression={$_.Col4}; Label="Column 4"; Width=30}
$data | Format-Table -Property $a

Note: I realize this is covered at the bottom of mklement0's more complete answer, but if this is your use case and you're scrolling quickly, I hope this helps highlight this strategy at a high level

Answer 2

To summarize and complement the helpful comments made by PetSerAl and Ansgar Wiechers:

tl;dr

Get-CimInstance -ClassName win32_operatingsystem -ComputerName $pclist |
  Sort-Object CSName |
    Format-Table CSName, LastBootUpTime -AutoSize

-AutoSize is what ensures that the CSName (computer name) column is as wide as it needs to be to show all values in full.

Get-CimInstance takes an array of computer names, so there's no need for a loop; however, since the target computers are queried in parallel, the order of objects returned will typically not match the input order of computer names - this is rectified with the Sort-Object CSName call.

Read on to learn more about table formatting.

---

At its core, your question is about how to control the output column width of tabular output, which applies to any cmdlet's output.

Use the Format-Table cmdlet (directly) for tabular output, not Select-Object: the purpose of Select-Object is to create custom objects, not to format output; if such objects (generally, instances of any type without predefined formatting views) happen to haven 4 or fewer properties, they are by default formatted with Format-Table behind the scenes (but you don't get to apply options); otherwise, it is Format-List that is implicitly used. ^{Thanks, PetSerAl.}

• Format-Table invariably limits output lines to the available screen width, which means:

  • Columns may not get printed at all.
  • The last column that is printed may have its value truncated, with the missing part indicated by ... (though note that all printed columns can have truncated values).

• If you want to create longer lines, pipe Format-Table's output to | Out-File -Width <int> or | Out-String -Stream -Width <int>; note that if you print the latter to the screen, lines will wrap (but the extra line breaks won't be part of the data).

  • Caveat: On Windows PowerShell, do NOT use -Width ([int]::MaxValue), because table-formatted data for types with formatting data is unconditionally right-padded with spaces to the full width, which can consume inordinate amounts of memory / space in the output file and you may even run out of memory. In PowerShell Core, this has been fixed as of at least v6.1.

  • An alternative on Windows (does not work in PowerShell Core on Unix-like platforms) is to use [console]::BufferWidth = <column-count> to widen the screen buffer to allow longer lines that don't wrap, but require horizontal scrolling.
    Additionally, on Windows it only works in the regular console, not in the ISE.

• To control column widths - which indirectly determines how many columns will fit - use the following parameters:

  • -AutoSize ... tells Format-Table to make columns as wide as necessary to fit all data values, but note that this can result in fewer (less typically: more) columns getting displayed.

  • -Wrap ... makes the values of the last column printed span multiple lines, if needed, to avoid truncation.

  • To specify custom column widths, pass a hashtable with a Width property as an element to Format-Table's -Property parameter; e.g., the following example limits the 1st output column to 5 characters:
    [pscustomobject] @{ prop1='1234567890'; prop2='other' } | Format-Table -Property @{ e='prop1'; width = 5 }, prop2
    If truncation occurs, the truncation indicator ... invariably takes up the last 3 characters of the truncated value; in the example above, the prop1 value renders as 12... for a total of 5 chars.
    Also, specifying at least one custom width means that you must explicitly enumerate all properties to output in the -Property argument, even the ones that don't need custom widths.