Run BASH built-in commands in Python?

19
votes

Is there a way to run the BASH built-in commands from Python?

I tried:

subprocess.Popen(['bash','history'],shell=True, stdout=PIPE)

subprocess.Popen('history', shell=True, executable = "/bin/bash", stdout=subprocess.PIPE)

os.system('history')

and many variations thereof. I would like to run history or fc -ln.

2
pythonbashcommandsubprocess
The second one looks right to me. What goes wrong with it? - Devin Jeanpierre
What about running a bash process and interacting with it? It may be simpler and useful for longer running commands or interacting with the shell (i.e. inputting a password after sudo). I think pexpect may fit that need. - Ehtesh Choudhury

2 Answers

18
votes

I finally found a solution that works.

from subprocess import Popen, PIPE, STDOUT
shell_command = 'bash -i -c "history -r; history"'
event = Popen(shell_command, shell=True, stdin=PIPE, stdout=PIPE, 
    stderr=STDOUT)

output = event.communicate()

Thank you everyone for the input.

16
votes
subprocess.Popen(["bash", "-c", "type type"])

this calls bash and tells bash to run the string type type, which runs the builtin command type on the argument type.

output: type is a shell builtin

the part after -c has to be one string. this will not work: ["bash", "-c", "type", "type"]