Send files from a remote host and receive them using iTerm2's coprocess feature.
I often ssh to remote machines. Sometimes it's a direct connection, but more often than not I have to first login to a corporate jumphost, then ssh from there to a deployment leader, then from there to my target machine. It's a royal pain if I need to copy files back to my Mac. I either have to set up a series of ssh tunnels (usually forbidden by policy) or have to copy files from one host to another across each hop (usually forbidden by lack of write permission on the intermediaries).
I need a way to transmit files over the existing ssh stdio. Ideally I'd use something like zmodem which is designed for this very purpose. Unfortunately it's not installed on the remote machines, and I don't have the ability to install new software.
My solution is sendfile. The sending end relies only on tools that are already installed on my remote machines: bash, tar, and base64. The 'sendfile' command is only six lines of shell script. The 'recvfile' command on my Mac is a custom Python script.
Sendfile starts by sending a unique string that I can use as a trigger in iTerm. When iTerm sees the string it runs recvfile as a co-process. Sendfile sends a base64-encoded tar file which recvfile unpacks.
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Put recvfile.py somewhere convenient on your Mac.
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Set up the following trigger in your iTerm profile:
- Regular Expression:
^\s*-\*-\{\{SENDFILE\}\}-\*-\s*$ - Action:
Run Silent Coprocess... - Parameters:
/usr/bin/python /path/to/recvfile.py
- Regular Expression:
-
On the remote machine, source 'sendfile.sh' (or copy the sendfile function into your .bashrc).
On the remote machine type "sendfile filename". Multiple filenames can be
given. You'll see the start string -*-{{SENDFILE}}-*- printed out, after
which iTerm will execute 'recvfile.py'. The received files are placed in
~/Downloads/ in a new directory named for the remote hostname and the current
date/time.
Copyright (c) 2016 Steve King, steve@narbat.com