Interactively communicating with a FORTRAN shell program - python

DAOPHOT is a FORTRAN-written software for performing astronomy tasks in images. A typical flow of its usage is:
Open a terminal (gnome-terminal in my case) and run ./daophot. I'm now within DAOPHOT's shell.
Prompts the user for a command, let's say ATTACH to input an image file. DAOPHOT runs and prompts the user again for more commands.
User gives another command, let's say PHOTOMETRY. DAOPHOT runs and prompts the user again.
For every command the user gives, DAOPHOT runs and prompts again and again until exit is typed. For my case, I have three specific commands that will run one after another, without variation (ATTACH, PHOTOMETRY and PSF, with the latter maybe run more than once).
Right now I'm simply trying to ATTACH a file. What I have tried:
Using subprocess, as seen/asked here and here:
import subprocess
p = subprocess.Popen(["gnome-terminal","--disable-factory","--","./daophot"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
p.stdin.write(input("ATTACH file.fits"))
For this case, DAOPHOT's shell opens but the ATTACH command is not executed. I close the shell and the string "ATTACH file.fits" appears in the IPython terminal, ending the subprocess. I've tried also to use p.communicate(input=input("ATTACH file.fits")), but got the same result.
Using pexpect, as seen/asked here and here:
import pexpect
p = pexpect.spawn("gnome-terminal --disable factory -- ./daophot")
p.expect(pexpect.EOF)
p.sendline("ATTACH file.fits")
In this case, DAOPHOT's shell opens but the ATTACH command is not accounted for as an input.
Finally, a DAOPHOT wrapper already exists, but the idea is to have this automatically and interactive Python version in our lab, so that we can change later if needed.
From what I understand in terms of pipelines, ./daophot is a subsubprocess runnning inside gnome-terminal, so when I use e.g. p.stdin.write(input("ATTACH file.fits") I am actually inputing this command into gnome-terminal, and not into ./daophot.
Any help is much appreciated.

Related

Issue with command prompt (windows) and python script after restarting script

I am trying to write a CLI program with python in windows. I recently came across an issue with argparse and my work-around was to clear the command prompt and re-run my script with the same arguments using this code:
sys.stdout.flush
os.execl(sys.executable, 'python', __file__, *sys.argv[1:])
This works perfectly until I try to input something into my program. I have this perpetual loop in my code which allows me to input a string and have it echoed back to me:
while True:
action = input("> ")
print(f'typed {action}')
but once I reach that point in the code, it does not work, this is my output:
This is the expected output up until after the red "Ready."
for some reason, the command prompt alternates between an input to my script, and an input to the command prompt, which are both prefaced with the wrong text, the ">" should be an input to my script, but that input is being sent to the command prompt, and the "...\raspi>" should be an input to the command prompt, but that input is being sent to my script. Anyone have any ideas as to why this is happening? Why it's alternating between my script and regular command prompt?
The solution I came to was to realize that the cprint() function of the colorama.py library does not return text and instead just calls the print function (I should have been able to deduce that through the name of the function). So all I had to do was to not set the description of my parser to a cprint() function and instead call cprint() when it's needed.

Call to several batch files through CMD doesn't block

I'm trying to call several install.bat files one after another with Python trough CMD.
It is necessary that each bat file be displayed in an interactive console window because it asks for some users instructions and that the python program only resume after each CMD process is resolved
Each install.bat file can take a pretty long time to finish its process.
My code is the following :
for game in games :
print("----------- Starting conversion for %s -----------" %game)
subprocess.call("start cmd /C " + "Install.bat", cwd=os.path.join(gamesDosDir,game), shell=True)
print("end")
But the console windows inside the shell are launched all at once and the "end" message appears event before any of them is finished, whereas I would like them appearing one by one and not go to the n+1 one until the n one is finished and the console window closed (either by user or automatically /K or /C then).
I understand this is some problems using CMD as call should be blocking. How to resolve that? Additionally, if possible how to keep it exactly the same and add 'Y' and 'Y' as default user input?
The most common way to start a batch file (or more generally a CLI command) if to pass it as an argument to cmd /c. After you comment I can assume that you need to use start to force the creation of a (new) command window.
In that case the correct way is to add the /wait option to the start command: it will force the start command to wait the end of its subprocess:
subprocess.call("start /W cmd /C " + "Install.bat", cwd=os.path.join(gamesDosDir,game),
shell=True)
But #eryksun proposed a far cleaner way. On Windows, .bat files can be executed without shell = True, and creationflags=CREATE_NEW_CONSOLE is enough to ensure a new console is created. So above line could simply become:
subprocess.call("Install.bat", cwd=os.path.join(gamesDosDir,game),
creationflags = subprocess.CREATE_NEW_CONSOLE)

Programmatically injecting command into Python Cmd's cmdloop

Using Python Cmd2 module (inherits from Cmd) to create a MyCmd CLI for my program. In most cases, I am just using my script normally with the built-in commands. The ‘quit’ command is implemented to do some cleanup for the script and subsequently exit. The Cmd2 module waits for input via the raw_input.
In a specific case, I want to programmatically invoke ‘quit’ instead of issuing it at the command line. This is done via a separate thread where a REST API translates a ‘quit’ POST to invoke quit on the main thread of the script.
I found a couple of SO questions that want to do something similar, but not exactly like this. I tried to follow the below example, but it didn’t work:
Python StringIO - selectively place data into stdin
Then I tried something simple. Basically did the below from the thread:
sys.stdin = StringIO('quit\n')
sys.stdin.flush()
It seems that the word 'quit' was injected, but the script would not do its clean exit. However, I could go back to the command line and simply press Enter, which would trigger the cleanup and exit process. Not sure why ‘\n’ was not being interpreted as Enter.
My cmd is simply invoked in the below manner:
mycmd = MyCmd()
mycmd.cmdloop()
How can I properly inject ‘quit’ into the cmdloop of Cmd?
Have you tried the cmd.onecmd("quit") method? I think it can be used to inject commands in the interpreter.

Python and subprocess input piping

I have a small script that launches and, every half hour, feeds a command to a java program (game server manager) as if the user was typing it. However, after reading documentation and experimenting, I can't figure out how I can get two things:
1) A version which allows the user to type commands into the terminal windoe and they will be sent to the server manager input just as the "save-all" command is.
2) A version which remains running, but sends any new input to the system itself, removing the need for a second terminal window. This one is actually half-happening right now as when something is typed, there is no visual feedback, but once the program is ended, it's clear the terminal has received the input. For example, a list of directory contents will be there if "dir" was typed while the program was running. This one is more for understanding than practicality.
Thanks for the help. Here's the script:
from time import sleep
import sys,os
import subprocess
# Launches the server with specified parameters, waits however
# long is specified in saveInterval, then saves the map.
# Edit the value after "saveInterval =" to desired number of minutes.
# Default is 30
saveInterval = 30
# Start the server. Substitute the launch command with whatever you please.
p = subprocess.Popen('java -Xmx1024M -Xms1024M -jar minecraft_server.jar',
shell=False,
stdin=subprocess.PIPE);
while(True):
sleep(saveInterval*60)
# Comment out these two lines if you want the save to happen silently.
p.stdin.write("say Backing up map...\n")
p.stdin.flush()
# Stop all other saves to prevent corruption.
p.stdin.write("save-off\n")
p.stdin.flush()
sleep(1)
# Perform save
p.stdin.write("save-all\n")
p.stdin.flush()
sleep(10)
# Allow other saves again.
p.stdin.write("save-on\n")
p.stdin.flush()
Replace your sleep() with a call to select((sys.stdin, ), (), (), saveInterval*60) -- that will have the same timeout but listens on stdin for user commands. When select says you have input, read a line from sys.stdin and feed it to your process. When select indicates a timeout, perform the "save" command that you're doing now.
It won't completely solve your problem, but you might find python's cmd module useful. It's a way of easily implementing an extensible command line loop (often called a REPL).
You can run the program using screen, then you can send the input to the specific screen session instead of to the program directly (if you are in Windows just install cygwin).

Retrieving Raw_Input from a system ran script

I'm using the OS.System command to call a python script.
example:
OS.System("call jython script.py")
In the script I'm calling, the following command is present:
x = raw_input("Waiting for input")
If I run script.py from the command line I can input data no problem, if I run it via the automated approach I get an EOFError. I've read in the past that this happens because the system expects a computer to be running it and therefore could never receive input data in this way.
So the question is how can I get python to wait for user input while being run in an automated way?
The problem is the way you run your child script. Since you use os.system() the script's input channel is closed immediately and the raw_input() prompt hits an EOF (end of file). And even if that didn't happen, you wouldn't have a way to actually send some input text to the child as I assume you'd want given that you are using raw_input().
You should use the subprocess module instead.
import subprocess
from subprocess import PIPE
p = subprocess.Popen(["jython", "script.py"], stdin=PIPE, stdout=PIPE)
print p.communicate("My input")
Your question is a bit unclear. What is the process calling your Python script and how is it being run? If the parent process has no standard input, the child won't have it either.

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