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 -C         


        

Answer 1

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.

To control the width of individual columns:

# Instead of a simple property name, 'prop1', pass a *hashtable*
# (@{ ... }`) with a 'width' entry to Format-Table
PS> [pscustomobject] @{ prop1='1234567890'; prop2='other' } |
       Format-Table -Property @{ e='prop1'; width = 5 }, prop2

prop1 prop2
----- -----
1234… other

^{Note: In Windows PowerShell, you'll see just 12... as the truncated value, because it uses 3 individual . characters to represent the truncation; in PowerShell [Core] 6+ this was improved to using a single character, … (HORIZONTAL ELLIPSIS, U+2026).}

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 or | Out-String -Stream -Width ; 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 = 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 (Windows PowerShell), only the last character (PowerShell [Core] 6+); in the example above, the prop1 value renders as 12... / 1234… 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.