How to capture binary stdout of a console exe run from Powershell? - powershell

Is it possible to get Powershell to read the stdout of an exe into a byte[] instead of the usual text processed array of lines?
Best I've been able to do is this:
cmd /c foo.exe > foo.tmp
$b = [io.file]::readallbytes('foo.tmp')
del foo.tmp
Yucky, not to mention it is not streamable. Any better way to do this?

Got some info from the PowerShell team. The short answer is that unfortunately, it is not easy. :-(
The medium length answer is: http://poshcode.org/2175.
The long answer is: Capture and Redirect Binary Process Output

Related

How to pass integers and strings from MATLAB to a PowerShell script?

I need to automate a test. The test itself is being written (by me) in MATLAB, has 5 stages, each stage ends with setting a value to an integer (uint16_t and uint8_t) and with a message. I have to pass these 5 integers and 5 strings to a PowerShell script because Jenkins can only run a PowerShell or Python script, but I'm not entirely sure how can I achieve that. I have never used PS or done any scripting, and there isn't much on the Internet on how to even run a MATLAB script with PowerShell. (Maybe I should check batch file scripts running MATLAB scripts.)
The only option I've found so far is writing into a (temporary) file with MATLAB, then reading from it (and deleting it), it could be a .txt file, or preferably a .csv file (although using csvwrite is not recommended by Mathworks), but this isn't very reliable. Can anyone suggest other methods to pass it more directly? The MATLAB file is not a function, but it can be made to be one that has these variables as outputs. Also, it's fine if the integers are cast to another integer type.
Like #TessellatingHeckler said the way is $results = matlab.exe yourscript.
Here is an example if you want more features when launch the tests like no display windows ,run in a batch mode or wait to the end of matlab execution.
runTestMatlab (){
result=$(matlab.exe -wait -nosplash -noFigureWindows -batch TestScript.m)
if [ $? -ne 0 ]; then
# Error with the Matlab run
echo $result
return 1
fi
echo "$result"
return 0
}
Then you can parse the result with awk or any other tool that you want.

Why is PowerShell typing chinese characters into my files?

I'm trying to make a system which turns the contents of a .txt file into a variable. This isn't my problem, though; for some reason, my files are reading characters I didn't enter, and can't use.
Please note: What I'm doing is in no way efficient, and I'm positive there are other ways to go about this, but this is the best way for me. Also, I'm not amazingly intelligent when it comes to coding. Just thought I'd throw that out there.
First, let me show you the system I have in place.
value.txt
4
This file has the contents which I'd like to make into a variable.
Batch Files
setcmdvar.bat
set cmdvar=
I leave this empty so that I can put the contents of value.txt at the end (more on this later).
start.bat
#echo off
call PowerShell.exe cd "C:\Users\%username%\Desktop\Folder"; $PSvar = Get-Content value.txt; $PSvar >> setcmdvar.bat
pause
call setcmdvar.bat
pause
echo The variable equals %cmdvar%.
pause
exit
The second line from start.bat creates this script in PowerShell:
PowerShell script
cd "C:\Users\%username%\Desktop\Folder\"
$PSvar = Get-Content value.txt; $PSvar >> setcmdvar.bat
This creates a variable in PowerShell, $PSvar, which equals the contents of value.txt; in our case, 4. Then, it puts $PSvar (4) at the end of setcmdvar.bat, using >>, which changes it to:
setcmdvar.bat (changed)
set cmdvar=4
Or, at least, it should, to my knowledge. Instead, it changes the file to this:
set Items=桔⁥瑳楲杮椠⁳業獳湩⁧桴⁥整浲湩瑡牯›⸢ †⬠䌠瑡来牯䥹普††††㨠倠牡敳䕲牲牯›㨨
嵛‬慐敲瑮潃瑮楡獮牅潲割捥牯䕤捸灥楴湯 †⬠䘠汵祬畑污晩敩䕤牲牯摉㨠吠牥業慮潴䕲灸捥整䅤䕴摮晏瑓楲杮 
Or some other strange combination of characters. I looked one up, and it was Chinese. There's also some other characters like †, ⬠, ›, ⸢, 
, and ⁳. I have no idea why these are being typed. Along with this, start.bat displays the following:
Press any key to continue . . .
(PowerShell script runs here)
'■s' is not recognized as an internal or external command,
operable program or batch file.
Press any key to continue . . .
The variable equals .
Press any key to continue . . .
(exit)
I did not type "■s," and I assume this may be the problem. Whatever it is, does anyone have any ideas?
P.S. I'm sorry if my code is complicated, or if it looks bad, but I have it this way for a reason. Mostly my incompetence, actually. But I think it's better that way.
Also, I know there are commands like for /f "delims=" %a in ('ver') do #set foobar=%a (I just took this off the internet) but I've tried commands like those, and I suppose I just don't understand them all that well, because they didn't work.
I appreciate the help!
It would probably be better to avoid the static setcmdvar.bat script and write it all in the script. Using -Encoding ascii is what keeps the output from being Unicode and having a BOM (Byte Order Mark) at the beginning. It has nothing to do with Chinese characters.
ECHO>"%USERPROFILE%\value.txt" 4
SET "CMDFILE=%USERPROFILE%\setcmdvar.bat"
powershell -NoLogo -NoProfile -Command ^
"'SET ""cmdvar=' + (Get-Content $Env:USERPROFILE\value.txt) + '""""' |" ^
"Out-File -FilePath %CMDFILE% -Encoding ascii"
pause
call "%CMDFILE%"
pause
echo The variable equals %cmdvar%
pause
EXIT /B 0
>> has its problems with mixing encodings. Plus it defaults to utf16. I recommend changing
$PSvar >> setcmdvar.bat
to
add-content setcmdvar.bat $PSvar
I'm not sure how to keep everything on one line. You can make setcmdvar.bat like this:
set cmdvar=^
So that it continues.

Manage inputs from external command in a powershell script

First, I would like to apologize in case that the title is not descriptive enough, I'm having a hard time dealing with this problem. I'm trying to build an automation for a svn merge using a powershell script that will be executed for another process. The function that I'm using looks like this:
function($target){
svn merge $target
}
Now, my problem occurs when there are conflicts in the merge. The default behavior of the command is request an input from the user and proceed accordingly. I would like to automatize this process using predefined values (show the differences and then postpone the merge), but I haven't found a way to do it. In summary, the workflow that I am looking to accomplish is the following:
Detect whether the command execution requires any input to proceed
Provide a default inputs (in my particular case "df" and then "p")
Is there any way to do this in powershell? Thank you so much in advance for any help/clue that you can provide me.
Edit:
To clarify my question: I would like to automatically provide a value when a command executed within a powershell script require it, like in the following example:
Requesting user input
Edit 2:
Here is a test using the snippet provided by #mklement0. Unfortunately, It didn't work as expected, but I thought it was wort to add this edition to clarify the question per complete
Expected behavior:
Actual result:
Note:
This answer does not solve the OP's problem, because the specific target utility, svn, apparently suppresses prompts when the process' stdin input isn't coming from a terminal (console).
For utilities that do still prompt, however, the solution below should work, within the constraints stated.
Generally, before attempting to simulate user input, it's worth investigating whether the target utility offers programmatic control over the behavior, via its command-line options, which is both simpler and more robust.
While it would be far from trivial to detect whether a given external command is prompting for user input:
you can blindly send the presumptive responses,
which assumes that no situational variations are needed (except if a particular calls happens not to prompt at all, in which case the input is ignored).
Let's assume the following batch file, foo.cmd, which puts up 2 prompts and echoes the input:
#echo off
echo begin
set /p "input1=prompt 1: "
echo [%input1%]
set /p "input2=prompt 2: "
echo [%input2%]
echo end
Now let's send responses one and two to that batch file:
C: PS> Set-Content tmp.txt -Value 'one', 'two'; ./foo.cmd '<' tmp.txt; Remove-Item tmp.txt
begin
prompt 1: one
[one]
prompt 2: two
[two]
end
Note:
For reasons unknown to me, the use of an intermediate file is necessary for this approach to work on Windows - 'one', 'two' | ./foo.cmd does not work.
Note how the < must be represented as '<' to ensure that it is passed through to cmd.exe and not interpreted by PowerShell up front (where < isn't supported).
By contrast, 'one', 'two' | ./foo does work on Unix platforms (PowerShell Core).
You can store the SVN command line output into a variable and parse through that and branch as you desire. Each line of output is stored into a new enumerator (cli output stored in PS variables is in array format)
$var = & svn merge $target
$var

Batch file to set a PowerShell variable

For some reason i simply can't understand most of the sites who explain this question. So i'll try to ask here, if i'm am in the wrong place, just tell me in the comments and i'll put this in another forum and delete this question.
Let's say that i have 2 files, Batch.bat and PowerShell.ps1.
Batch.bat:
set A="ThisIsSuchVar!"
PowerShell.ps1:
$B = "Well, i don't know what to do here"
What can i do to the B variable be the same as the A variable?
Remember: I want the Batch variable to go to the PowerShell file. It's an one-way script. I want to use the built-in windows sources. And please, consider that i am a complete newbie in programming and don't speak english very well, so be the simplest possible, please.
In your batch file run.bat, set the environment variable A and run the PowerShell script:
set A=8
PowerShell.exe -File .\script.ps1
pause
In script.ps1, get the environment variable A, and assign its value to B:
$B=$Env:A
echo $B
When you run run.bat you get:
C:\Temp\try>set A=8
C:\Temp\try>PowerShell.exe -File .\script.ps1
8
C:\Temp\try>pause
Press any key to continue . . .

Using Expect with Perl and pipe to a file

I'm fairly new to Perl and have been searching the interwebs for documentation for what I'm trying to do. I'm not having any luck.
I have a program that outputs information to stdout with prompts throughout. I need to make a Perl script to pipe that information to a file.
I thought I could use Expect but there seems to be a problem with the pipe after the first prompt.
Here is the part of my code:
# Run program and compare the output to the BASE file
$cmd = "./program arg1 arg2 arg3 arg4 > $outfile";
my $exp = new Expect;
$exp->spawn($cmd);
BAIL_OUT("couldn't create expect object") if (! defined $exp);
$exp->expect(2);
$exp->send("\n");
For this case there is only a single prompt for the user to press "enter". This program is small and very fast - 2 seconds is plenty of time to reach the first prompt.
The output file only contains the first half of the information.
Does anyone have any suggestions on how I can grab the second half as well?
UPDATE:
I've verified that this works with Expect by using a simple script:
spawn ./program arg1 arg2 arg3 arg4
expect "<Return>"
send "\r"
interact
Where "< Return >" is a verbose expression that the Perl script could look for.
Note: I've tried writing my Perl script to expect "< Return >"...it makes no difference.
i.e.
$exp->expect(2, '-re', "<Return>")
Any thoughts?
UPDATE2:
Hazaah! I've found a solution to my problem...completely by accident.
So, I had a mistype in some test code I made...
$exp->expect(2);
$exp->send("\r");
$exp->expect(2);
Note the trailing expect(2)...I accidentally left that in and it worked!
So, I'm trying to understand what is happening. Unix expect does not seem work this way! It appears Expect implemented in Perl "expects" anything...not just prompts?
So, I provided expect another 2 seconds to collect stdout and I am able to get everything.
If anyone can offer some more detailed information as to what is going on here I'd love to understand what is going on.
Try sending \r instead of \n - you're trying to emulate a carriage return, not a newline, and the tty settings might not be translating them.
ALSO:
A suggestion from the Expect docs FAQ section, which seems likely given your accidental solution:
My script fails from time to time without any obvious reason. It
seems that I am sometimes loosing output from the spawned program.
You could be exiting too fast without giving the spawned program
enough time to finish. Try adding $exp->soft_close() to terminate the
program gracefully or do an expect() for 'eof'.
Alternatively, try adding a 'sleep 1' after you spawn() the program.
It could be that pty creation on your system is just slow (but this is
rather improbable if you are using the latest IO-Tty).
Standard unix/tcl expect doesn't exit in interactive mode, which could give your program enough time to finish running.
It's been a while since I've used Expect, but I'm pretty sure you need to provide something for Expect to match the prompt against:
$exp->expect( 2, 'Press enter' );
for example.