How to output something in PowerShell

Question

I am running a PowerShell script from within a batch file  The script fetches a web page and checks whether the page s content is the string  OK    The PowerShell script returns an error level to the batch script   The batch script is executed by ScriptFTP  an FTP automation program  If an error occurs  I can have ScriptFTP send the full console output to the administrator via E-Mail   In the PowerShell script  I would like to output the return value from the web site if it is not  OK   so the error message gets included in the console output  and thus in the status mail   I am new to PowerShell and not sure which output function to use for this  I can see three    Write-Host Write-Output Write-Error   What would be the right thing to use to write to the Windows equivalent of stdout

User · Answer

You simply cannot get PowerShell to ommit those pesky newlines. There is no script or cmdlet that does this.

Of course Write-Host is absolute nonsense because you can't redirect/pipe from it! You simply have to write your own:

using System;

namespace WriteToStdout
{
    class Program
    {
        static void Main(string[] args)
        {
            if (args != null)
            {
                Console.Write(string.Join(" ", args));
            }
        }
    }
}

E.g.

PS C:\> writetostdout finally I can write to stdout like echo -n
finally I can write to stdout like echo -nPS C:\>

User · Answer

You can use any of these in your scenario since they write to the default streams  output and error   If you were piping output to another commandlet you would want to use Write-Output  which will eventually terminate in Write-Host   This article describes the different output options  PowerShell O is for Output

User · Answer

I think the following is a good exhibit of Echo vs  Write-Host  Notice how test   actually returns an array of ints  not a single int as one could easily be led to believe   function test       Write-Host 123     echo 456   AKA  Write-Output      return 789     x   test  Write-Host  x of type     x GetType   name      x   Write-Host    x 0       x 0    Write-Host    x 1       x 1      Terminal output of the above   123 x of type  Object      456 789  x 0    456  x 1    789

User · Answer

What would be the right thing to use to write to the Windows equivalent of stdout    In effect  but very unfortunately  both Windows PowerShell and PowerShell Core as of v7 0  send all of their 6    output streams to stdout when called from the outside  via PowerShell s CLI    See this GitHub issue for a discussion of this problematic behavior  which likely won t get fixed for the sake of backward compatibility  In practice  this means that whatever PowerShell stream you send output to will be seen as stdout output by an external caller    E g   if you run the following from cmd exe  you ll see no output  because the stdout redirection to NUL applies equally to all PowerShell streams    C   gt powershell -noprofile -command  Write-Error error    gt NUL  However - curiously - if you redirect stderr  PowerShell does send its error stream to stderr  so that with 2 gt  you can capture the error-stream output selectively  the following outputs just  hi  - the success-stream output - while capturing the error-stream output in file err txt    C   gt powershell -noprofile -command   hi   Write-Error error   2 gt err txt     The desirable behavior is    Send PowerShell s success output stream  number 1  to stdout  Send output from all other streams to stderr  which is the only option  given that between processes only 2 output streams exist - stdout  standard output  for data  and stderr  standard error  for error messages and all other types of messages - such as status information - that aren t data  It s advisable to make this distinction in your code  even though it currently isn t being respected      Inside PowerShell    Write-Host is for display output  and bypasses the success output stream - as such  its output can neither be  directly  captured in a variable nor suppressed nor redirected    Its original intent was simply to create user feedback and create simple  console-based user interfaces  colored output   Due to the prior inability to be captured or redirected  PowerShell version 5 made Write-Host to the newly introduced information stream  number 6   so since then it is possible to capture and redirect Write-Host output   Write-Error is meant for writing non-terminating errors to the error stream  number 2   conceptually  the error stream is the equivalent of stderr  Write-Output writes to the success  output  stream  number 1   which is conceptually equivalent to stdout  it is the stream to write data  results  to    However  explicit use of Write-Output is rarely needed due to PowerShell s implicit output feature     Output from any command or expression that isn t explicitly captured  suppressed or redirected is automatically sent to the success stream  e g   Write-Output  Honey  I m  HOME  and  Honey  I m  HOME  are equivalent  with the latter not only being more concise  but also faster

User · Answer

Write-Host  Found file -      File FullName -ForegroundColor Magenta   Magenta can be one of the  System ConsoleColor  enumerator values - Black  DarkBlue  DarkGreen  DarkCyan  DarkRed  DarkMagenta  DarkYellow  Gray  DarkGray  Blue  Green  Cyan  Red  Magenta  Yellow  White   The    File FullName is optional  and shows how to put a variable into the string

User · Answer

I think in this case you will need Write-Output   If you have a script like  Write-Output  test1   Write-Host  test2    test3     then  if you call the script with redirected output  something like yourscript ps1  gt  out txt  you will get test2 on the screen test1 ntest3 n in the  out txt    Note that  test3  and the Write-Output line will always append a new line to your text and there is no way in PowerShell to stop this  that is  echo -n is impossible in PowerShell with the native commands   If you want  the somewhat basic and easy in Bash  functionality of echo -n then see samthebest s answer   If a batch file runs a PowerShell command  it will most likely capture the Write-Output command  I have had  long discussions  with system administrators about what should be written to the console and what should not  We have now agreed that the only information if the script executed successfully or died has to be Write-Host ed  and everything that is the script s author might need to know about the execution  what items were updated  what fields were set  et cetera  goes to Write-Output  This way  when you submit a script to the system administrator  he can easily runthescript ps1  gt someredirectedoutput txt and see on the screen  if everything is OK  Then send the  someredirectedoutput txt  back to the developers

User · Answer

Simply outputting something is PowerShell is a thing of beauty - and one its greatest strengths  For example  the common Hello  World  application is reduced to a single line    Hello  World     It creates a string object  assigns the aforementioned value  and being the last item on the command pipeline it calls the  toString   method and outputs the result to STDOUT  by default   A thing of beauty   The other Write-  commands are specific to outputting the text to their associated streams  and have their place as such

[windows] How to output something in PowerShell

Examples related to windows

Examples related to powershell