What is the best WinAPI function to use when you only want to run a simple shell command like hg > test.txt?
To simply run a file, then ShellExecute() and CreateProcess() are the best options.
As you want to redirect output to a file/run a shell command, it complicates things...
Output redirection is a feature of the command prompt, and as such, the command you want to run needs to be passed to cmd.exe (on NT/XP+) passing /c and your command as the parameters (either ShellExecute or CreateProcess will do).
cmd /c "ipconfig >c:\debug\blah.txt"
The best way however is to use CreateProcess() and create your own pipes to talk to the stdin and stdout of the program (This is all cmd does internally)
You could use ShellExecute(), but why not try system() first? I am not so sure that ShellExecute() can actually do piping or redirection. There is also CreateProcess(), but that requires a bit more work. CreateProcess() gives you the best control, though.
There are two ways of issuing commands: the Windows Shell way, and the command line way.
Windows Shell issues commands by executing verbs on files. Verbs are associated with file types in the registry. Examples of common verbs are Open and Print. The WinAPI to use for this is ShellExecute. Windows Shell does not help you pipe the output of a process to a file. You can do it using CreateProcess, but it is a little bit involved.
The command line way is to use the system function.
Related
the title might be slightly confusing but what I need is a method to hand over pre-configured parameters to a batchfile on windows commandline.
The batchflie executes several progams (openssl) that need interactive input. To avoid this, I wrote all necessary input parameters to a textflie and now try to do something like:
type parameters.txt | mybatchfile.bat
Unfortunately this doesn't work.
Is there a way to do this?
Passing text into stdin of interactive prompts of console programs sometimes works, but needs to be done on single line of specific program. Tested way for SSH communication in batch file:
some batch code
echo n| plink.exe -pw "somepassword" root#somehost someremotecommand
some batch code
https://the.earth.li/~sgtatham/putty/latest/w32/plink.exe
The windows API provides GetCommandLine() which returns the cooked command line used to start a process.
For instance, if a console application is started with the command:
MyProg.exe > OutputHere
The command line seen by MyProg.exe will not include the portion
> OutputHere
I'd like to somehow get the command line exactly as it was. Is this possible ? and if yes, how ?
Suggestions in C and/or plain (no objects) Delphi greatly appreciated. Creative solutions welcome (hopefully, not requiring ring 0 code.)
Thank you very much for your help.
NOTE: I can tell if the input/output, etc has been redirected but, that is not what I'm looking for. I need the original/uncooked command line.
The redirection or piping of stdin, stdout and stderr is handled the command interpreter, typically cmd.exe. The interpreter parses the command and creates the necessary files and pipes, and then creates the one or more processes needed to implement your command.
The processes that are created have no knowledge of the original command, they only get that part of the command that is not related to piping and redirection.
So what you are trying to do is not possible, at least within your process. The only thing that knows the original command is the command interpreter.
Whether or not you can retrieve the full command line including the pipe commands depends on whether your start the program in a command window or for example using the "Run" command from the Start menu. If you use the "Run" command from the Start menu GetCommandLine actually retrieves the full command line including the redirection commands, but redirection does not work as it seems to be a feature of CMD.EXE.
As others have pointed out, what are you trying to achieve here / why do you need to capture the redirection commands?
I have a program that I work with, that has an onboard lua compiler to allow for custom written actions.
Since the tool itself is very limited, especially if it goes for complex reactions over networks, I want to use Powershell over lua.
Methods like os.execute() or io.popen() use the standard command line from windows and not Powershell.
Is there a way to use Powershell with lua?
I tried to write a command line script with the Powershell editor and run this script with os.execute, but it opens it as a textfile, it would be better to write the commands directly in lua but if there is no other way, executing a Powershell script directly would also be fine. (In Windows itself you can execute the script with right mouse "click/Execute with Powershell")
-- You can generate PowerShell script at run-time
local script = [[
Write-Host "Hello, World!"
]]
-- Now create powershell process and feed your script to its stdin
local pipe = io.popen("powershell -command -", "w")
pipe:write(script)
pipe:close()
Your description of the problem makes it sound like you're using a command such as os.execute("powershellscript.ps1"), and that call invokes cmd.exe with your string as the proposed command line. Normally, Windows will open a .PS1 file for editing; this was a deliberate decision for safety. Instead, try altering the os.execute() command to explicitly call PS: os.execute("powershell.exe -file powershellscript.ps1"). If you need to pass parameters to your script, enclose them in {}. See https://msdn.microsoft.com/en-us/powershell/scripting/core-powershell/console/powershell.exe-command-line-help for more info on invoking PowerShell from the command line.
I am trying to implement a terminal emulator in Java. It is supposed to be able to host both cmd.exe on Windows and bash on Unix-like systems (I would like to support at least Linux and Mac OS X). The problem I have is that both cmd.exe and bash repeat on their standard output whatever I send to their standard input.
For example, in bash, I type "ls", hit enter, at which point the terminal emulator sends the input line to bash's stdin and flushes the stream. The process then outputs the input line again "ls\n" and then the output of the ls command.
This is a problem, because other programs apart from bash and cmd.exe don't do that. If I run, inside either bash, or cmd.exe, the command "python -i", the python interactive shell does not repeat the input in the way bash and cmd.exe does. This means a workaround would have to know what process the actual output came from. I doubt that's what actual terminal emulators do.
Running "bash -i" doesn't change this behaviour. As far as I know, cmd.exe doesn't have distinct "interactive" and "noninteractive" modes.
EDIT: I am creating the host process using the ProcessBuilder class. I am reading the stdout and stderr and writing to the stdin of the process using a technique similar to the stream gobbler. I don't set any environment variables before I start the host process. The exact commands I use to start the processes are bash -i for bash and cmd for cmd.exe. I'll try to post minimal code example as soon as I manage to create one.
On Unix, run stty -echo to disable "local echo" (i.e. the shell repeating everything that you type). This is usually enabled so a user can edit what she types.
In your case, BASH must somehow allocate a pseudo TTY; otherwise, it would not echo every command. set +x would have a similar effect but then, you'd see + ls instead of ls in the output.
With cmd.exe the command #ECHO OFF should achieve the same effect.
Just execute those after the process has been created and it should work.
Can I use CreateProcess (or ShellExecute, or any other means of invoking cmd.exe to run a batch script) and have all output redirected to a pipe owned by my process? How do I give the child cmd.exe process a handle to one of the pipe endpoints? Is it even possible to use a pipe in this way?
(Googling for variations on the terms "cmd.exe" and "pipes" is nothing but redirecting output to another program using the |(pipe) character)
Here's how you would do it with .NET: http://msdn.microsoft.com/en-us/library/system.diagnostics.processstartinfo.redirectstandardoutput.aspx
And for C/C++: http://msdn.microsoft.com/en-us/library/ms682499(v=VS.85).aspx
Probably this will help... it is in VB.NET but it shouldn't be hard to change it to C#...
http://blogs.msdn.com/b/rahulso/archive/2006/04/01/run-a-command-from-the-command-prompt-and-get-its-output-in-a-windows-application.aspx