If I run echo a; echo b
in bash the result will be that both commands are run. However if I use subprocess then the first command is run, printing out the whole of the rest of the line.
The code below echos a; echo b
instead of a b
, how do I get it to run both commands?
import subprocess, shlex
def subprocess_cmd(command):
process = subprocess.Popen(shlex.split(command), stdout=subprocess.PIPE)
proc_stdout = process.communicate()[0].strip()
print proc_stdout
subprocess_cmd("echo a; echo b")
This question is related to
python
bash
subprocess
Join commands with "&&".
os.system('echo a > outputa.txt && echo b > outputb.txt')
>>> command = "echo a; echo b"
>>> shlex.split(command);
['echo', 'a; echo', 'b']
so, the problem is shlex module do not handle ";"
If you're only running the commands in one shot then you can just use subprocess.check_output
convenience function:
def subprocess_cmd(command):
output = subprocess.check_output(command, shell=True)
print output
I just stumbled on a situation where I needed to run a bunch of lines of bash code (not separated with semicolons) from within python. In this scenario the proposed solutions do not help. One approach would be to save a file and then run it with Popen
, but it wasn't possible in my situation.
What I ended up doing is something like:
commands = '''
echo "a"
echo "b"
echo "c"
echo "d"
'''
process = subprocess.Popen('/bin/bash', stdin=subprocess.PIPE, stdout=subprocess.PIPE)
out, err = process.communicate(commands)
print out
So I first create the child bash process and after I tell it what to execute. This approach removes the limitations of passing the command directly to the Popen
constructor.
import subprocess
cmd = "vsish -e ls /vmkModules/lsom/disks/ | cut -d '/' -f 1 | while read diskID ; do echo $diskID; vsish -e cat /vmkModules/lsom/disks/$diskID/virstoStats | grep -iE 'Delete pending |trims currently queued' ; echo '====================' ;done ;"
def subprocess_cmd(command):
process = subprocess.Popen(command,stdout=subprocess.PIPE, shell=True)
proc_stdout = process.communicate()[0].strip()
for line in proc_stdout.decode().split('\n'):
print (line)
subprocess_cmd(cmd)
Source: Stackoverflow.com