I would like to run this multiline shell commands:
echo 'a=?'
read a
echo "a=$a"
from a python script, using the subprocess.call() method.
I wrote this, in test.py file:
import shlex, subprocess
args = ["echo", 'a=?',"read", "a", "echo", "a=$a"]
subprocess.call(args)
and when I execute it, I have in terminal this report:
Armonicus#MyMacs-iMac MyNewFolder % python test.py
a=? read a echo a=$a
which is not at least close to what I expect.
Can I have some support from anyone, please?
There are a couple of issues with your approach here.
First, if what you're trying to do is prompt the user for input from the command line, then you can use Python builtins instead of a subprocess:
a = input('a=?')
print(a)
If you do want to call a subprocess with multiple commands, you need to either make separate calls for each command, or invoke a shell and execute the commands within it. For example:
subprocess.call("echo 'a=?'; read a; echo $a", shell=True)
Related
I am trying to create a bash script that runs a python3 script with pdb trace set. As such, in my bash script I have the following lines:
python3 path/to/my_script.py
n
What I want to happen is for bash to run the python script, which will then open the python debugger. Then, the bash script will send the key 'n' to the pdb shell so that pdb executes the first line in the python script.
The script does not work as expected and bash waits until the python script has completed (or exited) to execute 'n' in the command line which just opens node.
I thought this might be a problem unique to pdb shells so I tried executing the following in bash:
python3
print("Hello")
However, again, we observe that the script creates a python3 shell and then waits for the shell to exit before executing print("Hello") in the terminal. I understand that I could use python3 -c for this case, but that does not address the case of passing commands to the pdb shell in the context of the running script.
Is there any way to send the 'n' command to the pdb shell that the python script generates?
Your code will try to run two commands. First, it will run your python script, then it will try to run a command called n. Assuming your script needs you read from stdin you can do one of the following:
Use a herestring:
python3 path/to/my_script.py <<< "n"
Use a pipeline:
One example echo "n" | python3 path/to/my_script.py
Echo is not the only command you can use. You can also use printf or even yes for this use case.
You can use a coprocess to send and receive from pdb.
#! /bin/bash
send() {
echo "$1" >&${PDB[1]}
}
recv() {
IFS= read -r -u ${PDB[0]} line
echo $line
}
coproc PDB { /path/to/my_script.py; }
send 'n'
recv
#...
send 'n'
recv
I am trying to open one file from gnome-terminal using python. But I am not able to do it.It is just opening terminal and not opening file.
I have tried like:
import os
os.system('gnome-terminal --working-directory = "folder_path" + "[-e, --command=" kate aaa.txt""')
Can anyone please help?
The problem is + "[-e, --command=" kate aaa.txt"", gnome-terminal doesn't know how to parse this + "[ and "", according to the manual, -e and --command mean the same thing:
man gnome-terminal
...
--command, -e=COMMAND
Split the argument to this option into a program and arguments in the same way a shell
would, and execute the resulting command-line inside the terminal.
This option is deprecated. Instead, use -- to terminate the options, and put the program
and arguments to execute after it: for example, instead of gnome-terminal -e "python3 -q",
prefer to use gnome-terminal -- python3 -q.
Note that the COMMAND is not run via a shell: it is split into words and executed as a
program. If shell syntax is required, use the form gnome-terminal -- sh -c '...'.
This works for me in Archlinux:
import os
os.system('gnome-terminal --working-directory = /home/ramsay --command="kate
os"')
I want to execute commands in the terminal through a python scripts.
i want to create a script which takes data from a .txt file adds that in a list and then one by one execute them in the terminal.
what i am looking for is a process to execute commands in the terminal in Kali Linux, I couldn't find anything online.
like in windows we use import subprocess or import os
Thank you.
example command is like
python3 app.py
Try this:
import subprocess
command = "python3 app.py"
subprocess.call(command, shell=True)
You can use the os.system function. It returns the return value of the command run.
E.g.,
status = os.system('echo hello')
I'm trying to write a script that opens a new terminal then runs a separate python script from that terminal.
I've tried:
os.system("gnome-terminal 'python f.py'")
and
p = Popen("/usr/bin/gnome-terminal", stdin=PIPE)
p.communicate("python f.py")
but both methods only open a new terminal and do not run f.py. How would I go about opening the terminal AND running a separate script?
Edit:
I would like to open a new terminal window because f.py is a simply server that is running serve_forever(). I'd like the original terminal window to stay "free" to run other commands.
Like most terminals, gnome terminal needs options to execute commands:
gnome-terminal [-e, --command=STRING] [-x, --execute]
You probably need to add -x option:
x, --execute
Execute the remainder of the command line inside the terminal.
so:
os.system("gnome-terminal -x python f.py")
That would not run your process in the background unless you add & to your command line BTW.
The communicate attempt would need a newline for your input but should work too, but complex processes like terminals don't "like" being redirected. It seems like using an interactive tool backwards.
And again, that would block until termination. What could work would be to use p.stdin.write("python f.py\n") to give control to the python script. But in that case it's unlikely to work.
So it seems that you don't even need python do to what you want. You just need to run
python f.py &
in a shell.
As of GNOME Terminal 3.24.2 Using VTE version 0.48.4 +GNUTLS -PCRE2
Option “-x” is deprecated and might be removed in a later version of gnome-terminal.
Use “-- ” to terminate the options and put the command line to execute after it.
Thus the preferred syntax appears to be
gnome-terminal -- echo hello
rather than
gnome-terminal -x echo hello
Here is a complete example of how you would call a executable python file with subprocess.call Using argparse to properly parse the input.
the target process will print your given input.
Your python file to be called:
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("--file", help="Just A test", dest='myfile')
args = parser.parse_args()
print args.myfile
Your calling python file:
from subprocess import call
#call(["python","/users/dev/python/sandboxArgParse.py", "--file", "abcd.txt"])
call(["gnome-terminal", "-e", "python /users/dev/python/sandboxArgParse.py --file abcd.txt"])
Just for information:
You probably don't need python calling another python script to run a terminal window with a process, but could do as follows:
gnome-terminal -e "python /yourfile.py -f yourTestfile.txt"
The following code will open a new terminal and execute the process:
process = subprocess.Popen(
"sudo gnome-terminal -x python f.py",
stdout=subprocess.PIPE,
stderr=None,
shell=True
)
I am running a uWS server with this.In my case Popen didn't help(Even though it run the executable, still it couldn't communicate with a client -: socket connection is broken).This is working.Also now they recommends to use "--" instead of "-e".
subprocess.call(['gnome-terminal', "--", "python3", "server_deployment.py"])
#server_deployment.py
def run():
execution_cmd = "./my_executable arg1 arg2 dll_1 dll_2"
os.system(execution_cmd)
run()
I have the following function that is used to execute system commands in Python:
def engage_command(
command = None
):
#os.system(command)
return os.popen(command).read()
I am using the os module instead of the subprocess module because I am dealing with a single environment in which I am interacting with many environment variables etc.
How can I use Bash with this type of function instead of the default sh shell?
output = subprocess.check_output(command, shell=True, executable='/bin/bash')
os.popen() is implemented in terms of subprocess module.
I am dealing with a single environment in which I am interacting with many environment variables etc.
each os.popen(cmd) call creates a new /bin/sh process, to run cmd shell command.
Perhaps, it is not obvious from the os.popen() documentation that says:
Open a pipe to or from command cmd
"open a pipe" does not communicate clearly: "start a new shell process with a redirected standard input or output" -- your could report a documentation issue.
If there is any doubt; the source confirms that each successful os.popen() call creates a new child process
the child can't modify its parent process environment (normally).
Consider:
import os
#XXX BROKEN: it won't work as you expect
print(os.popen("export VAR=value; echo ==$VAR==").read())
print(os.popen("echo ==$VAR==").read())
Output:
==value==
====
==== means that $VAR is empty in the second command because the second command runs in a different /bin/sh process from the first one.
To run several bash commands inside a single process, put them in a script or pass as a string:
output = check_output("\n".join(commands), shell=True, executable='/bin/bash')
Example:
#!/usr/bin/env python
from subprocess import check_output
output = check_output("""
export VAR=value; echo ==$VAR==
echo ==$VAR==
""", shell=True, executable='/bin/bash')
print(output.decode())
Output:
==value==
==value==
Note: $VAR is not empty here.
If you need to generate new commands dynamically (based on the output from the previous commands); it creates several issues and some of the issues could be fixed using pexpect module: code example.