commands detail - e

    You use it as follows:

    As well as write-output there are a couple of options for use in Powershell scripts and functions:

    • write-debug
    • write-verbose

    Whether these produce any output is controlled by commandline or environment flags.

    echo -n

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

    1. $ echo -n Blue is the colour

    you get:

    1. Blue is the colour$

    ….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’. If you type:

    1. PS C:\Users\matt> write-host -nonewline "Blue is the colour"

    ….then you get this:

    1. PS C:\Users\matt> write-host -nonewline "Blue is the colour"
    2. Blue is the colourPS C:\Users\matt>

    Note that -nonewline doesn’t ‘work’ if you’re in the ISE.

    egrep

    The best PowerShell equivalent to or grep is select-string:

    1. select-string stamford blue_flag.txt

    Powershell is case-insensitive by default, so:

    …would return:

    1. blue_flag.txt:3:From Stamford Bridge to Wembley

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

    1. select-string  -casesensitive stamford blue_flag.txt

    egrep -v

    The Powershell equivalent to the -v option would be -notmatch

      egrep ‘this|that’

      To search for more than one string within a file in bash, you use the syntax:

      1. egrep 'blue|stamford' blue_flag.txt

      This will return lines which contain either ‘blue’ or ‘stamford’.

      The PowerShell equivalent is to seperate the two strings with a comma, so:

      1. $ select-string  stamford,blue blue_flag.txt

      …returns:

      This is an interesting one, in that it points up a conceptual difference between PowerShell and Bash.

      In bash, if you want to pipe into a grep, you would do this:

      1. ps -ef | egrep sql

      To do something similar in PowerShell you would do something more specific

      1. get-process | where processname -like '*sql*'

      So the string ‘sql’ has to match the contents of the property processname. As it happens, get-process by default only returns one text field, so in this case it’s relatively academic, but hopefully it illustrates the point.

      env

      The Linux ‘env’ shows all the environment variables.

      In PowerShell there are two set of environment variables:

      • windows-level variables and
      • Powershell-level variable

      Windows-level variables are given by:

      1. Get-ChildItem Env: | fl

      PowerShell-level variables are given by:

      1. get-variable

      errpt

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

      The PowerShell equivalent would be to look at the Windows eventlog, as follows

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

      The lognames that I typically look at are ‘system’, ‘application’ or ‘security’.

      In bash the following changes the prompt when you are at the command line

      1. function prompt {
      2.  }

      I found this on