powershell equivalents of unix commands

Source: powershell equivalents of unix commands




At it’s simplest, the powershell equivalent of the unix ‘alias’ is ‘set-alias’

set-alias ss select-string

However, there’s a slight wrinkle….

In *nix, you can do this

alias bdump="cd /u01/app/oracle/admin/$ORACLE_SID/bdump/"

If you try doing this in Powershell, it doesn’t work so well:

set-alias cdtemp "cd c:\temp"

You get:

cdtemp : The term 'cd c:\temp' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:1
+ cdtemp
+ ~~~~~~
    + CategoryInfo          : ObjectNotFound: (cd c:\temp:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

A way around is to create a function instead:

remove-item -path alias:cdtemp
function cdtemp {cd c:\temp}

you can then create an alias for the function:

set-alias cdt cdtemp


Apropos is one of my favourite bash commands, not so much for what it does, but because I like the word ‘apropos’.

I’m not sure it exists on all flavours of *nix, but in bash ‘apropos’ returns a list of all the man pages which have something to do with what you’re searching for. If apropos isn’t implemented on your system you can use man -k instead.

anyway on bash ‘apropos’ looks like this:

apropos process
AF_LOCAL [unix]      (7)  - Sockets for local interprocess communication
AF_UNIX [unix]       (7)  - Sockets for local interprocess communication
Apache2::Process     (3pm)  - Perl API for Apache process record
BSD::Resource        (3pm)  - BSD process resource limit and priority functions
CPU_CLR [sched_setaffinity] (2)  - set and get a process's CPU affinity mask
CPU_ISSET [sched_setaffinity] (2)  - set and get a process's CPU affinity mask
CPU_SET [sched_setaffinity] (2)  - set and get a process's CPU affinity mask
CPU_ZERO [sched_setaffinity] (2)  - set and get a process's CPU affinity mask
GConf2              (rpm) - A process-transparent configuration system

The Powershell equivalent of ‘apropos’ or ‘man -k’ is simply ‘get-help’

get-help process

Name                              Category  Module                    Synopsis
----                              --------  ------                    --------
get-dbprocesses                   Function                            Get processes for a particular databases [SH]
show-dbprocesses                  Function                            Show processes for a particular database [SH]
show-timeandprocesses             Function                            ...
function-show-timeandprocesses... Extern...                           function-show-timeandprocesses.ps1 ...
Debug-Process                     Cmdlet    Evil empire.PowerShell.M... Debugs one or more processes running on the local computer.
Get-Process                       Cmdlet    Evil empire.PowerShell.M... Gets the processes that are running on the local computer or a rem...

This is quite a nice feature of Powershell compared to Bash. If get-help in Powershell shell scores a ‘direct hit’ (i.e. you type something like ‘get-help debug-process’) it will show you the help for that particular function. If you type something more vague, it will show you a list of all the help pages you might be interested in.

By contrast if type ‘man process’ at the Bash prompt, you’d just get

No manual entry for process


dir  | select name

or, following on from a PowerShell.com ‘Power Tips of the Day’



There’s no one-liner equivalent for the Linux ‘cal’, but I’ve downloaded the code at:


… and turned it into a function




The unix ‘clear’ command clears your screen. The Powershell equivalent to the unix ‘clear’ is


PowerShell also has built-in alias ‘clear’ for ‘clear-screen’.

However, it’s possibly worth noting that the behaviour of the two commands is slightly different between the two environments.

In my Linux environment, running putty, ‘clear’ gives you a blank screen by effectively scrolling everything up, which means you can scroll back down. ‘Clear-screen’ on the other hand seems to wipe the previous output (actually in the same way that cmd’s cls command does….). This could be quite a significant difference, depending on what you want to clear and why!


The Posh version of cp is


The following are built-in aliases for copy-item:


cp -R

To recursively copy:

copy -recurse


The Powershell equivalent of the Unix ‘date’ is


The Powershell equivalent of the Unix ‘date -s’ is


I was anticipating doing a fairly tedious exercise of going through all the Unix date formats and then working out the Powershell equivalent, but discovered the Powershell Team has effectively done all this for me. There is a Powershell option


which stands for ‘unix format’.

So the Powershell:

date -Uformat '%D'

is the same as the *nix

date +'%D'

This is handy but I have found the odd difference. I tried this for a demo:

date +'Today is %A the %d of %B, the %V week of the year %Y. My timezone is %Z, and here it is %R'
Today is Monday the 08 of September, the 37 week of the year 2014. My timezone is BST, and here it is 17:24

get-date -Uformat 'Today is %A the %d of %B, the %V week of the year %Y. My timezone is %Z, and here it is %R'
Today is Monday the 08 of September, the 36 week of the year 2014. My timezone is +01, and here it is 17:25

I presume the discrepancy in the week of the year is to do with when the week turns – as you can see I ran the command on a Monday. Some systems have the turn of the week being Monday, others have it on Sunday.

I don’t know why %Z outputs different things….but I can’t help feeling I’m being churlish pointing this out. The -UFormat option is a really nice thing to have.

df -k

A quick and dirty Powershell equivalent to ‘df -k’ is

Get-WMIObject Win32_LogicalDisk -filter "DriveType=3" | ft

A slightly prettier version is this function:

function get-serversize { Param( [String] $ComputerName)

Get-WMIObject Win32_LogicalDisk -filter "DriveType=3" -computer $ComputerName | 
   Select SystemName, DeviceID, VolumeName,
          @{Name="size (GB)";Expression={"{0:N1}" -f($_.size/1gb)}},
          @{Name="freespace (GB)";Expression={"{0:N1}" -f($_.freespace/1gb)}} 

function ss { Param( [String] $ComputerName)
    get-serversize $ComputerName | ft

….then you can just do:

PS C:\Windows\system32> ss my_server 

SystemName                  DeviceID                    VolumeName                  size(GB)                    freespace(GB)
----------                  --------                    ----------                  --------                    -------------
my_server                   C:                          OS                          30.0                        7.8
my_server                   D:                          App                         250.0                       9.3
my_server                   E:                                                      40.0                        5.0


gi c:\temp\x.txt | select directory

Note: this isn’t a direct equivalent. The unix ‘dirname’ doesn’t care whether the file you specify exists or not. If you type in ‘dirname /tmp/tax_fiddle/google.doc’ on any server it will return ‘/tmp/tax_fiddle’, I think. ‘dirname’ is essentially a string-manipulation thing.

The Powershell equivalent above actually needs the file to really exist. You could get a direct equivalent using the split method on the string I think, but it would be a bit more long-winded….and not necessarily very much more useful.

Another note: for some reason or another, possibly not unrelated to the quantity of London Pride I swallowed last night, I was under the impression that the unix ‘dirname’ only returned the name of the folder immediately above the specified file, not the whole path. It doesn’t.

Anyway if you did want that from Powershell:

get-item $(get-item c:\temp\x.txt).directory | select name

….would return just


Another note: a more direct Powershell equivalent to the unix ‘dirname’ is this



While I think there are implementations of du in PowerShell, personally my recommendation would be to download Mark Russinovich’s ‘du’ tool, which is here:

Windows Sysinternals – Disk Usage

This is part of the Evil empire’s ‘sysinternals’ suite.



echo -n

‘echo -n’ echoes back the string without printing a newline, so if you do this:

$ echo -n Google paid �3.4m in 2011.

you get:

Google paid �3.4m in 2011.$

….with your cursor ending up on the same line as the output, just after the dollar prompt

Powershell has an exact equivalent of ‘echo -n’:

PS C:\Windows\system32> write-host -nonewline Google paid �3.4m in 2011.
Google paid �3.4m in 2011.PS C:\Windows\system32>

| egrep -i sql

i.e. pipe into an egrep.

| where {[Regex]::Ismatch($_.name.tolower(), "sql") } 

egrep -i

Powershell is case-insensitive by default

select-string elvis top1000.txt  

If you want to do a case sensitive search, then you can use:

select-string  -casesensitive Henry c:\henry8.txt

egrep -v

select-string -notmatch Henry c:\henry8.txt


The Linux ‘env’ shows all the environment variables.

In PowerShell there are two set of environment variables:

Windows-level variables, given by:

Get-ChildItem Env: | fl

PowerShell-level variables, given by:



I think errpt is just an AIX thing((the bash equivalent is, I think, looking at /var/log/message)). It shows system error and log messages

get-eventlog -computername bigserver -logname application -newest 15 

export PS1=”$ “

function prompt {
 "$ "

I don’t entirely understand this – but presumably Powershell looks for a function called prompt and runs it every time you hit return.

I found this on Fun with prompts – Richard Siddaway’s Blog


The bash ‘find’ command could or should perhaps have a page of Powershell equivalents to itself…maybe I’ll do that at some stage.

Anyway at it’s simplest the bash ‘find’ does this:

find . -name '*BB.txt'

The simplest Powershell equivalent of the bash ‘find’ is simply to stick a ‘-recurse’ on the end of a ‘dir’ command

PS x:\> dir  *BB.txt -recurse

    Directory: x:\Archive\WO8559B

Mode                LastWriteTime     Length Name
----                -------------     ------ ----
-----        28/02/2012     17:15        608 Script_WO8559_Master_ScriptBB.txt
-----        28/02/2012     17:17         44 WO8559_finalBB.txt
-----        28/02/2012     17:17      14567 WO8559_part1BB.txt
-----        28/02/2012     17:15       1961 WO8559_part2BB.txt

    Directory: x:\Archive

Mode                LastWriteTime     Length Name
----                -------------     ------ ----
-----        15/06/2011     08:56       2972 Script_WO7171BB.txt
-----        14/02/2012     16:39       3662 Script_WO8541BB.txt
-----        27/02/2012     15:22       3839 Script_WO8645_BB.txt

This may be what you want. If you want Powersehll to give you output that looks more like the Unix find then you can pipe into ‘| select fullname’

PS x:\> dir  *BB.txt -recurse | select fullname



for loop – foreach item in a list

For the Bash

for I in Chelsea Arsenal Spuds
  echo $I

the equivalent Powershell is:

foreach ($Team in ("Chelsea", "Arsenal", "Spuds")) {write-output $Team}

for loop – for each word in a string

For the bash:

london="Chelsea Arsenal Spurs"
for team in $london; do   echo "$team"; done

…the equivalent Powershell is:

$London = "Chelsea Arsenal Spuds"
foreach ($Team in ($London.split())) {write-output $Team}

for loop – start, stop, step

The equivalent of this bash:

  echo "Hello, world $i"

Hello, world 1
Hello, world 2
Hello, world 3
Hello, world 4
Hello, world 5


for ($i = 1; $i -le 5; $i++)
write-output "Hello, world $i"

Hello, world 1
Hello, world 2
Hello, world 3
Hello, world 4
Hello, world 5

for loops – for lines in a file


for team in $(egrep -v mill london.txt)
> do
>   echo $team
> done


select-string -notmatch millwall london.txt | select line | foreach {write-output $_}


foreach ($team in (select-string -notmatch millwall london.txt | select line)) {$team}

for loop – for each file in a folder


for LocalFile in *
  echo $LocalFile


foreach ($LocalFile in $(gci)) {write-output $LocalFile.Name}


gc henry8.txt | select-object -first 10



This is an alias for get-history

It’s worth noting that history doesn’t persist across PowerShell sessions.

PowerShell magazine has a way of coding around this by auto-magically saving the history on exit, and re-loading on startup, although presumably this wouldn’t work if, say, your PC crashed. Anyway the article is here:

PowerShell Magazine » #PSTip Automatically persist history

history | egrep -i elvis

history | select commandline | where-object {$_.commandline -like '*elvis*'} | fl


This isn’t Powershell, it’s a standard-ish Windows executable that on my machine lives in c:\windows\system32


Details are here: Evil empire Windows XP – Hostname


Actually this is if-then-elif-else

HOUR_OF_DAY=$(date +'%H') 

if  [ $HOUR_OF_DAY -lt 6 ]
  echo  "Still nightime"
elif [ $HOUR_OF_DAY -lt 12 ]
  echo "Morning has broken"
elif [ $HOUR_OF_DAY -lt 18 ]
  echo "After noon"
  echo "Nightime again"

…and this is the Powershell equivalent of the bash shell if-then-elif-else

[int]$HourOfDay = $(get-date -UFormat '%H')

if  ( $HourOfDay -lt 6 )
  write-output  "Still nightime"
elseif ( $HourOfDay -lt 12 )
  write-output "Morning has broken"
elseif ( $HourOfDay -lt 18 )
  write-output "After noon"
  write-output "Nightime again"

if [ -f “$FileName” ]


export FileName=~/.matt
if [ -f "$FileName" ]
    echo "$FileName found."
    echo "$FileName not found."


$FileName = "c:\powershell\.matt.ps1x"
if (test-path $FileName) 
  {echo "$FileName found"}
  {echo "$FileName not found"}



A typical usage in Powershell might be:

get-process | select starttime , id, ProcessName | where {$_.processname -like 'iex*'}
stop-process 5240

Just noticed there is actually a builtin alias ‘kill’ which will work just as well:

get-alias k*

CommandType     Name
-----------     ----
Alias           kill -> Stop-Process


At the time of writing, I haven’t tried it out but Chrissy LeMaire (website) has written

Script Invoke-Locate: PowerShell port of GNU findutils’ locate and updatedb

….which sounds ideal :)


Get-ChildItem or gci or dir

there’s also a get-item, but I’m not sure what that gives you beyond get-childitem

ls -ltr

…or in DOS dir /OD

dir c:\tax_dodgers | sort-object -property lastwritetime


gwmi Win32_USBControllerDevice


$PSEmailServer = "exchange_server.domain.co.uk"
send-mailmessage -to eric.schmidt@gmail.com -from tax.man@hrmc.gov.uk -subject "Pay fair taxes"





ps -ef


get-process -ComputerName bigserver Var* . 

ps -ef | grep oracle

get-process oracle

get-process oracle | select ProcessName, StartTime

get-process oracle | select ProcessName -expand Threads | 
  select Id,StartTime,TotalProcessorTime, WaitReason

….can also do the following:

get-process  | 
  where {$_.PeakWorkingSet -gt 1Mb } | select ProcessName,PeakWorkingSet




In *nix

read -p "How much tax did Google pay in 2011? " small_number
echo $small_number

In Powershell

$small_number = read-host "How much tax did Google pay in 2011? "
How much tax did Google pay in 2011? : £3.4m

To not echo the input to screen, it’s


and I think stty -echo/stty echo in bash






start-sleep -seconds 5


start-sleep -milliseconds 250

or just:

sleep 3

…will sleep for 3 seconds


gc c:\henry8.txt | sort-object

sort -uniq


gc c:\temp\2000.txt | sort | gu -asstring

Note: this only works as far I can see if you sort it first

Note 2: get-unique IS case sensitive

Note 3: I haven’t quite worked out the circumstances, but this seems to work better for me if I specify ‘-asstring’


You need to have the sql module loaded for this to work, or be running the sqlplus thing from within SSMS

Invoke-Sqlcmd -ServerInstance -query "Select blah" -database _catalog 


I don’t know of a direct PowerShell equivalent to the unix ‘strings’ command, but there is a version of strings in Evil empire’s Sysinternals suite: Strings


gc henry8.txt | select-object -last 10

tail -f

gc -tail 10 -wait c:\windows\windowsupdate.log


The Powershell equivalent of the bash shell ‘time’ is ‘measure-command’.

So, in bash you would do this:

time egrep ORA- *log

….and get all the egrep output, then

real    0m4.649s
user    0m0.030s
sys     0m0.112s

In Powershell, you would do this

measure-command {select-string ORA- *.sql}

…and get…

Days              : 0
Hours             : 0
Minutes           : 0
Seconds           : 0
Milliseconds      : 105
Ticks             : 1057357
TotalDays         : 1.22379282407407E-06
TotalHours        : 2.93710277777778E-05
TotalMinutes      : 0.00176226166666667
TotalSeconds      : 0.1057357
TotalMilliseconds : 105.7357

…you don’t get the ‘user CPU’ time and ‘system CPU’ time, but you do get the added bonus of seeing how long the command took rendered as a fraction of a day!


Tnsping is actually an Oracle tool which checks whether the Oracle listener is up without logging onto the database. Using a .udl file isn’t really a direct equivalent, but it’s a handy place to record this

set-content -Path d:\temp\test_connection.udl -Value ($null)

…then for this file

ii -Path d:\temp\test_connection.udl

The set-content bit was gotten from Super User, the contributor being user techie007

touch – create an empty file

set-content -Path c:\temp\new_empty_file.dat -Value $null

I found the set-content command at set-content bit was gotten from Super User, the contributor being user techie007

touch – update the modified date

set-itemproperty -path c:\temp\new_empty_file.dat -name LastWriteTime -value $(get-date)

I got this from a comment by Manung Han on the Lab49 Blog. Doug Finke sharestouch function in a later comment on the same post that fully implements the linux command.

wc -l

gc c:\temp\file.txt | measure-object | select count

to show the number of non-blank lines:

gc c:\temp\file.txt | measure-object -line

Was reminded of this by article on measure-object at: Evil empire Certified Professional Magazine Online


[Security.Principal.WindowsIdentity]::GetCurrent() | select name

whence or type

Couple of things here at least.

This shows the sort of thing (exe, bat, alias, function):

get-command whoami

CommandType     Name                                               ModuleName
-----------     ----                                               ----------
Application     whoami.exe

….and if it what you’re looking for is a file in the path, this will find it

foreach ($FOLDER in $ENV:PATH.split(";") ) { dir $FOLDER\whoami.exe -ea Si | select fullname }


This splits the path into its constituent folders, then does a ‘dir’ to see if the file (in this case I’m looking for whoami.exe) and returns the full path and file if it’s there.


remove-item -path alias:cdtemp

uname -s

uname -s in Unix, according to the man page, gives the ‘kernel-version’ of the OS. This is the ‘top-level version’ of the Unix that you’re on. Typical values are ‘Linux’, or ‘AIX’ or ‘HP-UX’. So, on my laptop, typing uname -s gives:


I’ve only used this when writing a Unix script which have to do slightly different things on different flavours of unix.

Obviously, there’s only one manufacturer for Windows – Evil empire[^1]. So there’s no direct equivalent to uname -s. The closest equivalent on Powershell would I think be:

get-wmiobject -class win32_operatingsystem | select caption

This returns:

Evil empire Windows 7 Professional

Evil empire Windows 8.1 Pro
Evil empire(R) Windows(R) Server 2003, Standard Edition
Evil empire Windows Server 2008 R2 Enterprise
Evil empire Windows Server 2012 Standard

uname -n

According to the Linux help, uname -n does this:

       -n, --nodename
              print the network node hostname

So, typing uname -n gives

$ uname -n

I haven’t found a neat equivalent for this in Powershell, but this works:

get-wmiobject -class win32_computersystem  | select dnshostname, domain

The output is:

dnshostname                                                 domain
-----------                                                 ------
nancy                                                       one2one.co.uk

uname -r

uname -r gives the kernel release in Unix. The output varies depending on the flavour of Unix – Wikipedia has a good list of examples

On my system uname -r gives:


The best Powershell equivalent would seem to be:

get-wmiobject -class win32_operatingsystem | select version

…which gives:


The 7601 is Evil empire’s build number.

uname -v

uname -v typically gives the date of the unix build. As far a I can think, there isn’t a Powershell equivalent

uname -m

To be honest, I’m not entirely sure what uname -m shows us on Unix. The wikipedia page for uname shows various outputs none of whic hare hugely useful.

Running uname -m on my server gives:


Is this a PowerShell equivalent?

$ get-ciminstance -class cim_computersystem | select SystemType
x64-based PC

uname -m

Get-WmiObject -Class Win32_ComputerSystem | select manufacturer, model


On most, but from memory possibly not all, flavours of *nix ‘uptime’ tells you how long the server has been up and running

$ uptime
 15:54:24 up 9 days,  5:43,  2 users,  load average: 0.10, 0.09, 0.07

A rough equivalent to show how long the swerver (or PC) has been running Powershell is:

get-wmiobject -class win32_operatingsystem  | select LastBootUpTime

….of course you can also do

get-wmiobject -class win32_operatingsystem -ComputerName my_server | select LastBootUpTime

…to get the bootup time for a remote server, or PC.

I turned this into a couple of functions and an alias to get the info I most often need and format it nicely

function get-os {
Param ( [String] $ComputerName = ".")

get-wmiobject -class win32_operatingsystem -computer $ComputerName |
    select __Server,
function show-os {
Param ( [String] $ComputerName = ".")

get-os $ComputerName | 
  ft @{Label="Server"; Width = 12 ; Expression={$_.__Server}},
     @{Name="Versh" ; Width=30; Expression = {$_.caption.replace('Evil empire Windows ','') } },
     @{Label="SPMajor"; Width = 7; Expression={$_.ServicePackMajorVersion}},
     @{Label="SPMinor"; Width = 7; Expression={$_.ServicePackMinorVersion}},
     @{l="Version"; e={$_.Version }; Width = 12},
     @{l="Install"; e={$_.InstallDate.substring(0,8) }; width=9},
     @{Label="Booted"; Expression={$_.LastBootUpTime.substring(0,12)}; width=14}

set-alias sos show-os

So having loaded this I just run:
PS C:\Windows\system32> sos myserver

Server Versh SPMajor SPMinor Version Install Booted
—— —– ——- ——- ——- ——- ——
myserver Evil empire(R) Windows(R) Ser… 2 0 5.2.3790 20111213 2014040217

\ (line continuation)

The Powershell line continuation character is the horrible ‘backtick’ i.e. this:


On my leopard, the backtick is to the left of the ‘1’ key.


shutdown -r - restart-computer

crontab -l

ls -R


free (memory)
fuser filename


& (run in background)
PS1 (line contunuation prompt)
declare -F
Parameter passing
cut -f 3
for (p127)
while (p139)
select p113, p136
String comparisons p118
File attribute operations p122
Number comparisons p126
IFS (internal field separator) p127
getopts p145
let p145
arrays p160
here -documents p165
debugging stuff p221 
-n (syntax check)

#todo10 #todo
keyword: poshbash poshunix

  1. i = 1 ; i <= 5 ; i++ [↩]