On 21Feb2016 14:18, Philip Rhoades <phil(a)pricom.com.au&gt; wrote: [...] Because quoting shell commands to dispatch over ssh is tedious, I have this script: https://bitbucket.org/cameron_simpson/css/src/tip/bin/sshx which accepts an unquoted command line and does the work for you, so your request would be written: sshx localhost find /your/music/dir -maxdepth 1 -type f \( -name \*.mp3 -o -name \*.m4a -o -name \*.flac i.e. exactly as you would without the leading "ssh localhost" to an shell prompt. Please feel free to fetch it (use the "Raw" link at top right) and use it. It saves a lot of pain. BTW, why "localhost"? Or is this just an example for test, to be used on other hosts later when working? All this means is that you need to take your shell command line, once you have a working one, and quote it again to express it correctly as a Ruby string. Bear with me, because I don't yet speak Ruby. SO first get your shell command line. Make it as simple as feasible. If you've fetched my "sshx" script, that can be: sshx localhost find ... quoted no more than any local "find" command would be. Now express that as a Ruby string: https://en.wikibooks.org/wiki/Ruby_Programming/Syntax/Literals#Strings Since you're using double quotes to allow # interpolation (this is not a great practive for command lines, to which we'll come later) you probably want to either run with a command line with no double quotes in it and with all the backslashes doubled: shcmd = "sshx localhost find /dir -name \\*.mp3 ..." If _are_ using a command line with double quotes, they can also be escaped, eg: shcmd = "sshx localhost find /dir -name \"*.mp3\" ..." I'm imagining that you're expecting to replace "localhost" or the directory with something like #{remotehost} and #{path} later, thus: shcmd = "sshx #{remotehost} find #{path} -name \"*.mp3\" ..." and here we come to the issue of quoting yet again. Supposing your path has spaces or other shell punctuation in it. You also need to quote it, _before_ using it in your command line string. I find it useful to have a "shell quote" function in my kit, whatever the language. You can take any string to be used in the shell undamaged and suitable quote it by replacing all single quotes with: '\'' and enclosing the whole result in a pair of single quotes. You would need to do this for the variable you want to interpolate: qpath = shqstr(path) qremotehost = shqstr(remotehost) and then interpolate _those_ values: shcmd = "sshx #{qremotehost} find #{qpath} -name \"*.mp3\" ..." and finally running: system(shcmd) However, it is better to avoid going through the shell at all if it is only an intermediary to running a single command (your single "ssh" command). Using system() with a carefully quoted string has all the same fiddliness as passing carefully constructed SQL to a database query: any tiny flaw in the quoting can lead to incorrect behaviour, and if any of the strings come from user input, that is also an avenue for attack (there are known as injection attacks, where use input is injected into a command you issue, perverting your intent): http://bobby-tables.com/ The URL above uses SQL because it is an incredibly command misuse, but htis issue applies equally well to shell commands constructed the way you are constructing them. To avoid going though the shell at all you want to invoke your command with the Subprocess Ruby module: http://www.rubydoc.info/github/stripe/subprocess/Subprocess Construct your command as a list of strings: cmd = ['sshx', remotehost, 'find', path, '-name', '*.mp3', ...] and invoke Subprocess.popen to collect the resulting output. Notice that there's no quoting there at all, including of things like *.mp3. This is because the shell will never see these strings, and therefore you need only present them directly as valid Ruby strings. Cheers, Cameron Simpson <cs(a)zip.com.au&gt;