It seems after testing that the solution I discovered last night (described in the first post, edit command.rb so it won't escape backticks) is a correct and robust solution.
* The quoted command is run on the remote host. * It works when remote user's default shell is tcsh. * It works when remote user's default shell is bash. * It works when default_run_options[:shell]=false (though it will then run tcsh if that's your default shell) * It works when default_run_options[:shell] is not set. * 'rake test' reports all tests passing. I pushed the change to github scottj97/capistrano. On 19 May, 13:30, Jamis Buck <[email protected]> wrote: > It's only possible if you are using an interactive (e.g., login) shell > with SSH, and Capistrano is not. Believe me, I've explored and explored > this, trying to find ways to make Capistrano friendly to non-posix > shells, and "sh -c ..." is the closest I got. > > - Jamis > > On 5/19/09 2:25 PM, Scott Johnson wrote: > > > I guess I'm getting way beyond my expertise here, but is it possible > > to specify a shell when you SSH? Instead of taking the default shell? > > > I tried default_run_options[:shell]=false in my real capfile, but of > > course that led to shell syntax errors in the builtin Rails recipes > > (specifically deploy:rollback) because it's using tcsh, not sh > > anymore. > > > On 19 May, 12:15, Jamis Buck<[email protected]> wrote: > >> I'll bet it's tcsh. Capistrano calls "sh -c ..." specifically to work > >> around issues with non-posix shells; it sure sucks when those non-posix > >> shells make it impossible to make posix calls. > > >> I'm afraid it's looking like your only option is going to be to change > >> your default shell to something posix. :( > > >> - Jamis > > >> On 5/19/09 12:47 PM, Scott Johnson wrote: > > >>> Adding :shell => false to the run params does work. But I would still > >>> like to resolve this. I'm probably not the last person that will > >>> encounter this problem with Capistrano, and while it's evidently not > >>> the tool's fault, if there's something Cap can do to avoid it, that > >>> would be nice. > >>> I think it's clearly something with my environment. I tried the sh -c > >>> command on all the bash versions I could find, all using the same > >>> environment, and they all failed. > >>> 3.1.17(1)-release (i686-redhat-linux-gnu) > >>> 3.1.7(1)-release (x86_64-redhat-linux-gnu) > >>> 2.0.5a.0(1)-release (i686-pc-linux-gnu) > >>> 3.00.15(1)-release (i686-redhat-linux-gnu) > >>> But when I ran at home (WinXP, msysGit bash, with the default msysGit > >>> environment), it worked fine. > >>> One difference is the shell I'm launching from: tcsh (my default shell > >>> on those systems) in all the broken cases. When I launch sh -c from > >>> bash itself, it works. Perhaps tcsh is mangling the command before > >>> invoking sh? Here's a clue: > >>> % echo "foo is \`date\`" > >>> foo is \ > >>> I don't understand that. > >>> On 19 May, 10:39, Jamis Buck<[email protected]> wrote: > >>>> Maybe it's something with that version of GNU bash? This one works for > >>>> me: > >>>> $ sh --version > >>>> sh --version > >>>> GNU bash, version 3.2.17(1)-release (i386-apple-darwin9.0) > >>>> Copyright (C) 2005 Free Software Foundation, Inc. > >>>> It also works fine with the posix shell in Ubuntu (not sure which > >>>> version of Ubuntu, but fairly recent). > >>>> Also, I think I led you astray with the set(:shell, false) nonsense. The > >>>> correct way to set that is either this: > >>>> run("echo today is `date`", :shell => false) > >>>> or > >>>> default_run_options[:shell] = false > >>>> The former only applies to that run invocation; the latter applies > >>>> globally to all run invocations. > >>>> - Jamis > >>>> On 5/19/09 11:32 AM, Scott Johnson wrote: > >>>>> Getting closer! Something is wacked with my shell: > >>>>> % sh -c "echo today is \`date\`" > >>>>> today is > >>>>> % sh --version > >>>>> GNU bash, version 3.1.17(1)-release (i686-redhat-linux-gnu) > >>>>> Copyright (C) 2005 Free Software Foundation, Inc. > >>>>> Perhaps I have some environment variable set wrong or something? > >>>>> Jamis, the capfile I posted in my original message is the complete > >>>>> capfile. I tried adding set :shell, false and it made no difference. > >>>>> I suppose the change I made to command.rb is incorrect because the > >>>>> backticked command will be run locally instead of remotely. (Right?) > >>>>> On 19 May, 09:47, Jamis Buck<[email protected]> wrote: > >>>>>> The reason it is escaped is because Capistrano invokes the command via > >>>>>> 'sh' (by default). E.g., the following run command: > >>>>>> run "echo today is `date`" > >>>>>> Gets translated into the following shell command: > >>>>>> sh -c "echo today is \`date\`" > >>>>>> The backticks need to be escaped so that they get evaluated by the > >>>>>> inner > >>>>>> shell, and not the outer shell. > >>>>>> That said, what does the rest of your capfile look like? Are you > >>>>>> setting > >>>>>> :shell anywhere? What version of the posix shell do you have on your > >>>>>> remote host? > >>>>>> You might also try setting :shell to false, so that all commands are > >>>>>> invoked directly: > >>>>>> set :shell, false > >>>>>> That way, commands will be run without wrapping them in a "sh -c ..." > >>>>>> call. > >>>>>> - Jamis > >>>>>> On 5/19/09 10:33 AM, Scott Johnson wrote: > >>>>>>> I don't believe it is a permissions thing. I can run the same command > >>>>>>> not in backticks and it works. I can run the backticked command > >>>>>>> directly (not through Capistrano) and it works as expected: > >>>>>>> date is Tue May 19 09:25:51 PDT 2009 so there > >>>>>>> And I can edit Capistrano's source as described above and get it to > >>>>>>> work. > >>>>>>> There is something going on with Capistrano's escaping of the > >>>>>>> backticks that I don't understand. Why is it necessary on every > >>>>>>> computer except mine to escape the backticks? And why, when they are > >>>>>>> escaped on my machine, does the backticked command simply disappear > >>>>>>> without a trace? > >>>>>>> I can't imagine what could be so different on my machine. I realize > >>>>>>> I'm running an old Fedora, but things like backticks and shell escape > >>>>>>> characters haven't changed in 25 years. > >>>>>>> On 19 May, 08:10, Lee Hambley<[email protected]> wrote: > >>>>>>>> Scott, > >>>>>>>> Hate to respond with a classic `worksforme` -- may it be that your > >>>>>>>> user > >>>>>>>> (humor me) doesn't have access to do any of the things you are > >>>>>>>> asking, try > >>>>>>>> something like run('touch `echo date`') or similar. > >>>>>>>> To save potential email formatting issues, please post the code, > >>>>>>>> output and > >>>>>>>> error all in a gist/pastie and post us the links. > >>>>>>>> - Lee > >>>>>>>> 2009/5/19 Scott Johnson<[email protected]> > >>>>>>>>> No difference. Not only is the output of the backticked command not > >>>>>>>>> getting into the string, the command itself is never being run. I > >>>>>>>>> can > >>>>>>>>> replace the command with `touch file.txt` and that file is never > >>>>>>>>> created. > >>>>>>>>> On 19 May, 01:26, Lee Hambley<[email protected]> wrote: > >>>>>>>>>> Try, > >>>>>>>>>> task :foo, :hosts => "my.host.com" do > >>>>>>>>>> run "echo date is `cat /bin/date` so there" > >>>>>>>>>> end > >>>>>>>>>> 2009/5/19 Scott Johnson<[email protected]> > >>>>>>>>>>> I have a run command that uses shell backticks, yet the command > >>>>>>>>>>> in the > >>>>>>>>>>> backticks never runs and I get an empty string instead of the > >>>>>>>>>>> output > >>>>>>>>>>> of the command. > >>>>>>>>>>> My Capfile: > >>>>>>>>>>> task :foo, :hosts => "my.host.com" do > >>>>>>>>>>> run "echo date is `/bin/date` so there" > >>>>>>>>>>> end > >>>>>>>>>>> Output from running 'cap foo': > >>>>>>>>>>> * executing 'foo' > >>>>>>>>>>> * executing "echo date is `/bin/date` so there" > >>>>>>>>>>> servers: ["my.host.com"] > >>>>>>>>>>> [my.host.com] executing command > >>>>>>>>>>> ** [out :: my.host.com] date is so there > >>>>>>>>>>> command finished > >>>>>>>>>>> Bizarre. > >>>>>>>>>>> I'm running cap 2.5.5 on Fedora Core release 6 with Ruby 1.8.7. > >>>>>>>>>>> The > >>>>>>>>>>> local and remote machine are the same (ie, I'm launching cap from > >>>>>>>>>>> my.host.com). > >>>>>>>>>>> If I edit line 212 of lib/capistrano/command.rb (that escapes > >>>>>>>>>>> certain > >>>>>>>>>>> special characters in the command) and remove the backtick from > >>>>>>>>>>> the > >>>>>>>>>>> gsub args, it works. But I somehow doubt this is the proper > >>>>>>>>>>> solution, > >>>>>>>>>>> since I seem to be the only one having this problem. --~--~---------~--~----~------------~-------~--~----~ To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/capistrano -~----------~----~----~----~------~----~------~--~---
