CODEWITHSUNDEEP
pythonsubprocess
M Leonard
M Leonard

Reputation: 591

echo'ing commands (with returns) into Popen stdin

I'd like to run an fdisk function in python, but the returns are making this not work...

command = ['echo', '-e', "'o\nn\np\n1\n\n\nw'", '|', 'sudo', 'fdisk', '/dev/xvdm']
p = subprocess.Popen(command, stdin=subprocess.PIPE, 
                              stdout=subprocess.PIPE, 
                              stderr=subprocess.PIPE)
output, err = p.communicate()

This gives the the (incorrect) output of: b"'o\nn\np\n1\n\n\nw' | sudo fdisk /dev/xvdm\n"

What is the equivalent?

Upvotes: 0

Views: 831

Answers (2)

Guillaume L.
Guillaume L.

Reputation: 23

You can not use a pipe (|) in a command like this. The pipe is given as argument to the program ("echo" in your case).

scnerd give you the best way/answer to send input text to fdisk.

If you really want to keep the pipe, you shall run a "bash" program with argument "-c" (command), and give in parameter the command (including your pipe) :

command = ['bash', '-c', "echo -e 'o\nn\np\n1\n\n\nw' | sudo fdisk /dev/xvdm"]
p = subprocess.Popen(command, stdin=subprocess.PIPE, 
                     stdout=subprocess.PIPE, 
                     stderr=subprocess.PIPE)
output, err = p.communicate()

Upvotes: 1

scnerd
scnerd

Reputation: 6103

Why not just run fdisk and send it the input yourself?

command = ['sudo', 'fdisk', '/dev/xvdm']
p = subprocess.Popen(command, stdin=subprocess.PIPE, 
                              stdout=subprocess.PIPE, 
                              stderr=subprocess.PIPE)
output, err = p.communicate(b"o\nn\np\n1\n\n\nw")

Upvotes: 2

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