Execute multiple commands in Paramiko so that commands are affected by their predecessors

Question

I am slowly trying to make a python script to SSH then FTP to do some manual file getting I have to do all the time. I am using Paramiko and the session seems to command, and prints the directory but my change directory command doesn't seem to work, it prints the directory I start in: /01/home/.

import paramiko

hostname = ''
port = 22
username = ''
password = ''
#selecting PROD instance, changing to data directory, checking directory
command = {
    1:'ORACLE_SID=PROD',2:'cd /01/application/dataload',3:'pwd'
}

ssh=paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(hostname,port,username,password)

for key,value in command.items():
    stdin,stdout,stderr=ssh.exec_command(value)
    outlines=stdout.readlines()
    result=''.join(outlines)
    print (result)
ssh.close()

Answer 1

When you run exec_command multiple times, each command is executed in its own "shell". So the previous commands have no effect on an environment of the following commands.

If you need the previous commands to affect the following commands, just use an appropriate syntax of your server shell. Most *nix shells use a semicolon or an double-ampersand (with different semantics) to specify a list of commands. In your case, the ampersand is more appropriate, as it executes following commands, only if previous commands succeed:

command = "ORACLE_SID=PROD && cd /01/application/dataload && pwd"
stdin,stdout,stderr = ssh.exec_command(command)

---

In many cases, you do not even need to use multiple commands.

For example, instead of this sequence, that you might do when using shell interactively:

cd /path
ls

You can do:

ls /path

---

See also: How to get each dependent command execution output using Paramiko exec_command

---

Obligatory warning: Do not use AutoAddPolicy on its own – You are losing a protection against MITM attacks by doing so. For a correct solution, see Paramiko "Unknown Server".

Answer 2

Well by accidentally trying something I managed to figure this out I believe. You need to do all the commands at one time and do not need to do them in a loop. for for my instance it would be

import paramiko

hostname = ''
port = 22
username = ''
password = ''
#selecting PROD instance, changing to data directory, checking directory
command = 'ORACLE_SID=PROD;cd /01/application/dataload;pwd'
ssh=paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(hostname,port,username,password)
stdin,stdout,stderr=ssh.exec_command(value)
outlines=stdout.readlines()
result=''.join(outlines)
print (result)
ssh.close()