I'm trying to execute a shell command using Python's subprocess. This is how I do it:
pelican = 'pelican content -s /home/pelican/publishconf.pyt -D --ignore-cache'
subprocess.call(pelican, shell=True)
But the response is command not found. It doesn't have a problem when I write in my command line.
My question is how can I execute a shell command using python that behaves just like I would type it in?
Related
From this stackoverflow thread https://stackoverflow.com/questions/4443...mmand-line, I have extracted this command line:
gimp-console -idf --batch-interpreter python-fu-eval -b "import sys;sys.path=['.']+sys.path;import batch;batch.run('./images')" -b "pdb.gimp_quit(1)"
It works perfectly well.
Now, I would like to run this command from a Python script, usually I use subprocess.Popen but this time it does not work and I get this message:
"batch command experienced an execution error"
How can I launch the GIMP command line from a Python script?
One easy way to resolve this is to just put your GIMP startup script into a bash script, say startgimp.sh
#!/bin/bash
#set your path to GIMP or cd into the folder where you installed GIMP
gimp-console -idf --batch-interpreter python-fu-eval -b "import sys;sys.path=['.']+sys.path;import batch;batch.run('./images')" -b "pdb.gimp_quit(1)"
then from Python simply call the bash script like so
import subprocess
subprocess.call(["bash","/path/to/your/script/startgimp.sh"])
If you are able to make the .sh script executable, e.g. chmod +x startgimp.sh then you can skip the bash part and just do subprocess.call("/path/to/your/script/startgimp.sh")
Some caveats
This is assuming you're on a UNIX based system
I used subprocess.call so this WILL block while waiting for GIMP to complete. Use Popen like you've used if you don't want this
I don't have GIMP to try this out, but you could also try splitting your GIMP command into elements in the list and pass it to subprocess and see if that works.
e.g. subprocess.call(["gimp-console","-idf","--batch-interpreter","python-fu-eval" and so on)
I have the following code that works great to run the ls command. I have a bash alias that I use alias ll='ls -alFGh' is it possible to get python to run the bash command without python loading my bash_alias file, parsing, and then actually running the full command?
import subprocess
command = "ls" # the shell command
process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=None, shell=True)
#Launch the shell command:
output = process.communicate()
print (output[0])
Trying with command = "ll" the output I get is:
/bin/sh: ll: command not found
b''
You cannot. When you run a python process it has no knowledge of a shell alias. There are simple ways of passing text from parent to child process (other than IPC), the command-line and through environment (i.e. exported) variables. Bash does not support exporting aliases.
From the man bash pages: For almost every purpose, aliases are superseded by shell functions.
Bash does support exporting functions, so I suggest you make your alias a simple function instead. That way it is exported from shell to python to shell. For example:
In the shell:
ll() { ls -l; }
export -f ll
In python:
import subprocess
command = "ll" # the shell command
process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=None, shell=True)
output = process.communicate()
print(output[0].decode()) # Required if using Python 3
Since you are using the print() function I have assumed you are using python 3. In which case you need the .decode(), since a bytes object is returned.
With a bit of hackery it is possible to create and export shell functions from python as well.
I'm trying to run a python script from python using the subprocess module and executing a script sequentially.
I'm trying to do this in UNIX but before I launch python in a new shell I need to execute a command (ppack_gnu) that sets the environment for python (and prints some lines in the console).
The thing is that when I run this command from python subprocess the process hangs and waits for this command to finish whereas when I do it in the UNIX console it jumps to the next line automatically.
Examples below:
From UNIX:
[user1#1:~]$ ppack_gnu; echo 1
You appear to be in prefix already (SHELL=/opt/soft/cdtng/tools/ppack_gnu/3.2/bin/bash)
1
[user1#1:~]$
From PYTHON:
processes.append(Popen("ppack_gnu; echo 1", shell=True, stdin = subprocess.PIPE))
This will print Entering Gentoo Prefix /opt/soft/cdtng/tools/ppack_gnu/3.2 - run 'bash -l' to source full bash profiles
in the python console and then hang...
Popen() does not hang: it returns immediately while ppack_gnu may be still running in the background.
The fact that you see the shell prompt does not mean that the command has returned:
⟫ echo $$
9302 # current shell
⟫ bash
⟫ echo $$
12131 # child shell
⟫ exit
⟫ echo $$
9302 # current shell
($$ -- PID of the current shell)
Even in bash, you can't change environment variables of the parent shell (without gdb or similar hacks) that is why source command exists.
stdin=PIPE suggests that you want to pass commands to the shell started by ppack_gnu. Perhaps you need to add process.stdin.flush() after the corresponding process.stdin.write(b'command\n').
I need to run some bash commands via Fabric API (ssh).
I have the following String in my Python module:
newCommand = command + "'`echo -ne '\\015'"
When I print this string directly in Python the output is the expected:
command'`echo -ne '\015'
However, if I try to run this command via the Fabric API the command is somehow modified into this:
/bin/bash -l -c "command'\`echo -ne '\015'"
Notice the '\' before 'echo'. Why is this happenning? The '\' is breaking my command and I can't successfuly run the command.
ps: The prefix "/bin/bash -l -c" is expected since that's how Fabric works with SSH
This is not a valid shell command:
command'`echo -ne '\015'
Even if you add the missing backtick and single quote, it's nothing like writing "command" and pressing enter.
The context your command will be run in is basically what you'd get if you'd ssh and paste a command:
clientprompt$ ssh host
Welcome to Host, User
hostprompt$ <COMMAND HERE>
You should focus your efforts on finding a single command that does what you want, and not a series of keypresses that you could write to do it (that's not how ssh works).
I use python module pysftp to connect to remote server. Below you can see python code :
import pysftp
import sys
import sqr_common
srv = pysftp.Connection(host="xxxxxx", username="xxxx",
password="xxxxx")
command = "/usr/bin/bash"
command2="APSHOME=/all/aps/msc_2012; export APSHOME; "
srv.execute(command)
srv.execute(command2)
srv.close()
Problem is that command /usr/bin/bash is an infinite process , so my script will never be executed. Can anyone help me how to choose shell on remote server for example bash and execute command in bash on remote server?? Is there any pysftp function that allows me chosing shell??
try this
/usr/bin/bash -c "APSHOME=/all/aps/msc_2012; export APSHOME; "
This problem is not specific to Python, but more like how to execute commands under specific shell.
If you need to run only single command you can run using bash -c switch
bash -c "echo 123"
You can run multiple commands ; separated
bash -c "echo 123 ; echo 246"
If you need to many commands under a specific shell, remotely create a shell script file (.bash file) an execute it
bash myscript.bash