7 ms·

Show HN: ssh and cd get married

44 points by ChristianBundy 13y ago

aegiso 13y ago
TL;DR: a 3 line exercise in bash argument munging. t="${!#}" c=("ssh" "-t" "${@:1:$(($#-1))}" "${t%:*}" "cd ${t##*:}; \$SHELL -l") "${c[@]}" That's literally the whole repo.
- ChristianBundy 13y ago
  Literally. We both know that it would've been easier to write this in Python, Ruby, Javascript, etc., but at the cost of using an "uncool" language I was able to solve the problem in three lines with only bash as a dependency. Pull requests welcome.
  - blueskin_ 13y ago
    I am thankful you didn't. Congratulations on getting the *NIX philosophy right.
    - lmm 13y ago
      If that's the ★nix philosophy I don't want to be a ★nix person any more. Seriously, even my VMS machines have python installed, and a script I can read is a lot better than one I can't, even if the one I can read has an extra dependency.
      - blueskin_ 13y ago
        Python isn't too bad (unless you're calling the script in a lot of separate instances), but python is fairly neat compared to ruby/javascript/whatever trendy language of the week as it doesn't need a huge pile of worthless dependencies itself.
    - aet 13y ago
      http://en.wikipedia.org/wiki/Unix_philosophy http://en.wikipedia.org/wiki/Unix_philosophy "The Unix philosophy emphasizes building short, simple, clear, modular, and extendable code that can be easily maintained and repurposed by developers other than its creators. The philosophy is based on composable (rather than contextual) design."
- dpacmittal 13y ago
  Can you explain this code?
  - ChristianBundy 13y ago
    Definitely. Here's a gist, feel free to comment with any questions! https://gist.github.com/christianbundy/8954786 https://gist.github.com/christianbundy/8954786
    - gcommer 13y ago
      Why not distribute that as the code in the repo instead of the compressed version?
aaronbasssett 13y ago
echo "cd /your/favorite/folder" >> ~/.bashrc
- lukeholder 13y ago
  This is by far is the best option, its still user based so it will take me where I want.
  - ChristianBundy 13y ago
    Absolutely – I'd definitely recommend that this is used in favor of my utility if you're always going to the same directory. I originally wrote a util that outputs your current username, hostname, and path (https://github.com/christianbundy/whereami https://github.com/christianbundy/whereami) so that you can either share or save it somewhere, but since SSH doesn't handle file paths by default I made a utility that does. :)
    - mhandley 13y ago
      I think you've done an excellent job of pointing out that ssh should just be capable of doing this by default. Like many such things, it's obvious with hindsight. But somehow I never thought of it before.
ams6110 13y ago
If you are an Emacs user, Tramp does this, e.g. you can open a file like: /user@example.com:/some/remote/path/file.dat Directory navigation (dired) works too, you can also open a shell in the remote directory (M-x shell)
- pcx 13y ago
  Enabling ido-mode makes it a lot more easier to use. Also, you can open local files as sudo in a similar way. /sudo:localhost:/etc/hosts
- drstrangevibes 13y ago
  +1 also from within eshell cd proto:user@location:/filepath where proto can be ftp, ssh , and some others
spindritf 13y ago
Alternatively, you could keep a tmux session open on the server and just attach it on connect. That way you can have everything arranged just the way you left it on disconnect. Same applications running, multiple windows, splits, etc. And you don't even need to start a new shell on connect. ssh user@host -t tmux attach You can add an alias for it. alias backtowork='ssh -t user@host tmux attach -t worksession' The last argument allows you to attach a chosen session if you have more than one running.
- ChristianBundy 13y ago
  Awesome, I hadn't though of that. My terminal automatically logs into my server via SSH and I just use my tmux aliases from there (minus the SSH, of course), but that would be a great way to do it if I developed locally. Thanks for the tip!
  - GrinningFool 13y ago
    Hm, why only for developing locally? The benefit of tmux/screen is that you can run it remotely, and reconnect to your session-in-progress at any time.
- dpacmittal 13y ago
  I use screen and it works well. The first thought when I saw this post was of screen and tmux. Anyone spending any kind of serious time in remote server through ssh should use screen/tmux.
  - teh_klev 13y ago
    I totally agree, a lot more of my work life is spent on our Linux platform. tmux is a godsend due to my sometimes flaky VPN connection.
- martinp 13y ago
  I do something similar. Instead of passing the tmux attach command to ssh, I attach (or create) a tmux session if the shell is a) a login shell and b) started in a SSH session. [0] [0] https://github.com/martinp/dotfiles/blob/master/dot.zlogin https://github.com/martinp/dotfiles/blob/master/dot.zlogin
krsumeet 13y ago
Using tmux on the server and attaching sessions on the client is a better option.
m0g 13y ago
plus if you're going for bash instead of python to avoid dependencies, just go for sh. It's not like it would be hard to code or anything in sh.
colinbartlett 13y ago
I hate little extensions like this because if I make them part of my workflow, I am completely hindered when I find myself on a machine that doesn't have this. (Every other machine in the world.)
- hyperbovine 13y ago
  In this particular instance, the command is saving you a total of two keystrokes. "You could probably get by in a pinch."
- ChristianBundy 13y ago
  Absolutely! I'm really only using this for SCP-like syntax when SSHing into unfamiliar boxes. WARNING: SHAMELESS SELF-PROMOTION BELOW Unless, you know, you used something like homes(h)ick... https://github.com/technicalpickles/homesick https://github.com/technicalpickles/homesick
bkase 13y ago
I like to take advantage of temporal locality. My zshrc is configured to take me to the most recent place that I have been whenever I open a new shell: autoload -U add-zsh-hook record_pwd() { pwd > ~/.cwd } add-zsh-hook chpwd record_pwd touch ~/.cwd cd `cat ~/.cwd`
akerl_ 13y ago
I'm trying really hard to see the utility in this, as somebody who almost obsessively aliases commands to save keystrokes. But it's almost the same number of keys, at the expense of having to mix them together. This feels less like a marriage and more like trying to tie two very different animals together. I'd much prefer if this was some kind of host-alias based magic, where "ssh my_server_web" took my to "my_server:/srv/http/my_site", "ssh my_server_db" took me to my_server and opened mysql, etc.
nkuttler 13y ago
There are two things I find odd about this solution. You still have to type the path you want to cd to. See previous discussion at https://news.ycombinator.com/item?id=6229001 https://news.ycombinator.com/item?id=6229001 for possible solutions. The github example specifies the username to ssh to. Assuming you ssh to the host more than once see man ssh_config and the User parameter. And screen/tmux, obviously.
vladimirralev 13y ago
It would be much more useful if you can make an scp with autocomplete by pressing tab in the terminal. scp root@host:/long(tab)_file_name .
- praseodym 13y ago
  zsh can do this :)
- bencoder 13y ago
  That's always worked by default for me on Ubuntu (assuming ssh keys etc)
- ChristianBundy 13y ago
  Funny you mention it, I actually have this working! (http://i.imgur.com/8VBYDd4.png http://i.imgur.com/8VBYDd4.png) You can check out my dotfiles (https://github.com/christianbundy/dotfiles https://github.com/christianbundy/dotfiles), but I'm pretty sure that the functionality came standard with one of my Zsh submodules, Prezto (https://github.com/sorin-ionescu/prezto https://github.com/sorin-ionescu/prezto).
jedanbik 13y ago
I think it's a cool exploration. Thanks for sharing.
- ChristianBundy 13y ago
  Thanks for the sincere comment! I hope you have a kickass Wednesday.
kijin 13y ago
Even better: make the script work with local paths as well. Then you can put alias cd='sshcd' in your .bashrc, and you won't have to distinguish between local and remote paths ever again.
- ChristianBundy 13y ago
  I was thinking about aliasing cd like that and instead having psuedo-directories that you can cd into to SSH into another box. The biggest problem though would be moving around in the box, as `cd ..` wouldn't take you back to your local machine. What do you think?
  - crnixon 13y ago
    Take a look at https://github.com/spencertipping/cd https://github.com/spencertipping/cd. It will let you cd to local or remote machines the same way, and will take you back to your local machine on "cd ..". (It mounts the remote fs instead of SSHing there.)
niklasber 13y ago
Any benefits with this over running something like this? Other than it being shorter and easier for someone not familiar with console commands? ssh -t yourserver.com 'cd /some/dir/;exec /bin/sh'
- tostada 13y ago
  Doesn't look like it.
- ChristianBundy 13y ago
  Nope, that's actually very close to what it does. I didn't develop this because the keystrokes were difficult, I just know that both git and SCP support this syntax and couldn't think of any good reason why SSH shouldn't.
pskocik 13y ago
A pretty cool improvement. And you can easily add remote directory autocompletion if you simply steal the autocompletion function of `scp`: complete|sed -n 's/ scp$/ sshcd/p'
neoteric 13y ago
For what it's worth, this is broken when the target directory contains spaces/wildcard characters, etc. I would suggest you consider using something like the following to generate the command line you pass to ssh: printf -v cmd 'cd %q && $SHELL -l' "$target_dir" Also, dropping the ':' and just having an additional argument would make your life a bit simpler. What's with the array assignment just to invoke the command? Seems a bit unnecessary. The microoptimizer in me tells me you should use 'exec' as well :).
ahassan 13y ago
What shell and theme is he using?
- ChristianBundy 13y ago
  I'm using Zsh with Prezto (https://github.com/sorin-ionescu/prezto https://github.com/sorin-ionescu/prezto), a fork of oh-my-zsh.
rjzzleep 13y ago
a version that works inside your zsh scripts. there may be a better way to do it t=${@[$#]} c=("ssh" "-t" "${@:1:$(( $# -1 ))}" "${t%:}" "cd ${t##:}; \$SHELL -l") "${c[@]}"

TL;DR: a 3 line exercise in bash argument munging. t="${!#}" c=("ssh" "-t" "${@:1:$(($#-1))}" "${t%:*}" "cd ${t##*:}; \$SHELL -l") "${c[@]}" That's literally the whole repo.

ChristianBundy 13y ago
Literally. We both know that it would've been easier to write this in Python, Ruby, Javascript, etc., but at the cost of using an "uncool" language I was able to solve the problem in three lines with only bash as a dependency. Pull requests welcome.
- blueskin_ 13y ago
  I am thankful you didn't. Congratulations on getting the *NIX philosophy right.
  - lmm 13y ago
    If that's the ★nix philosophy I don't want to be a ★nix person any more. Seriously, even my VMS machines have python installed, and a script I can read is a lot better than one I can't, even if the one I can read has an extra dependency.
    - blueskin_ 13y ago
      Python isn't too bad (unless you're calling the script in a lot of separate instances), but python is fairly neat compared to ruby/javascript/whatever trendy language of the week as it doesn't need a huge pile of worthless dependencies itself.
  - aet 13y ago
    http://en.wikipedia.org/wiki/Unix_philosophy http://en.wikipedia.org/wiki/Unix_philosophy "The Unix philosophy emphasizes building short, simple, clear, modular, and extendable code that can be easily maintained and repurposed by developers other than its creators. The philosophy is based on composable (rather than contextual) design."
dpacmittal 13y ago
Can you explain this code?
- ChristianBundy 13y ago
  Definitely. Here's a gist, feel free to comment with any questions! https://gist.github.com/christianbundy/8954786 https://gist.github.com/christianbundy/8954786
  - gcommer 13y ago
    Why not distribute that as the code in the repo instead of the compressed version?

aaronbasssett 13y ago

echo "cd /your/favorite/folder" >> ~/.bashrc

lukeholder 13y ago
This is by far is the best option, its still user based so it will take me where I want.
- ChristianBundy 13y ago
  Absolutely – I'd definitely recommend that this is used in favor of my utility if you're always going to the same directory. I originally wrote a util that outputs your current username, hostname, and path (https://github.com/christianbundy/whereami https://github.com/christianbundy/whereami) so that you can either share or save it somewhere, but since SSH doesn't handle file paths by default I made a utility that does. :)
  - mhandley 13y ago
    I think you've done an excellent job of pointing out that ssh should just be capable of doing this by default. Like many such things, it's obvious with hindsight. But somehow I never thought of it before.

ams6110 13y ago

If you are an Emacs user, Tramp does this, e.g. you can open a file like: /user@example.com:/some/remote/path/file.dat Directory navigation (dired) works too, you can also open a shell in the remote directory (M-x shell)

pcx 13y ago
Enabling ido-mode makes it a lot more easier to use. Also, you can open local files as sudo in a similar way. /sudo:localhost:/etc/hosts
drstrangevibes 13y ago
+1 also from within eshell cd proto:user@location:/filepath where proto can be ftp, ssh , and some others

spindritf 13y ago

Alternatively, you could keep a tmux session open on the server and just attach it on connect. That way you can have everything arranged just the way you left it on disconnect. Same applications running, multiple windows, splits, etc. And you don't even need to start a new shell on connect. ssh user@host -t tmux attach You can add an alias for it. alias backtowork='ssh -t user@host tmux attach -t worksession' The last argument allows you to attach a chosen session if you have more than one running.

ChristianBundy 13y ago
Awesome, I hadn't though of that. My terminal automatically logs into my server via SSH and I just use my tmux aliases from there (minus the SSH, of course), but that would be a great way to do it if I developed locally. Thanks for the tip!
- GrinningFool 13y ago
  Hm, why only for developing locally? The benefit of tmux/screen is that you can run it remotely, and reconnect to your session-in-progress at any time.
dpacmittal 13y ago
I use screen and it works well. The first thought when I saw this post was of screen and tmux. Anyone spending any kind of serious time in remote server through ssh should use screen/tmux.
- teh_klev 13y ago
  I totally agree, a lot more of my work life is spent on our Linux platform. tmux is a godsend due to my sometimes flaky VPN connection.
martinp 13y ago
I do something similar. Instead of passing the tmux attach command to ssh, I attach (or create) a tmux session if the shell is a) a login shell and b) started in a SSH session. [0] [0] https://github.com/martinp/dotfiles/blob/master/dot.zlogin https://github.com/martinp/dotfiles/blob/master/dot.zlogin

krsumeet 13y ago

Using tmux on the server and attaching sessions on the client is a better option.

m0g 13y ago

plus if you're going for bash instead of python to avoid dependencies, just go for sh. It's not like it would be hard to code or anything in sh.

colinbartlett 13y ago

I hate little extensions like this because if I make them part of my workflow, I am completely hindered when I find myself on a machine that doesn't have this. (Every other machine in the world.)

hyperbovine 13y ago
In this particular instance, the command is saving you a total of two keystrokes. "You could probably get by in a pinch."
ChristianBundy 13y ago
Absolutely! I'm really only using this for SCP-like syntax when SSHing into unfamiliar boxes. WARNING: SHAMELESS SELF-PROMOTION BELOW Unless, you know, you used something like homes(h)ick... https://github.com/technicalpickles/homesick https://github.com/technicalpickles/homesick

bkase 13y ago

I like to take advantage of temporal locality. My zshrc is configured to take me to the most recent place that I have been whenever I open a new shell: autoload -U add-zsh-hook record_pwd() { pwd > ~/.cwd } add-zsh-hook chpwd record_pwd touch ~/.cwd cd `cat ~/.cwd`

akerl_ 13y ago

I'm trying really hard to see the utility in this, as somebody who almost obsessively aliases commands to save keystrokes. But it's almost the same number of keys, at the expense of having to mix them together. This feels less like a marriage and more like trying to tie two very different animals together. I'd much prefer if this was some kind of host-alias based magic, where "ssh my_server_web" took my to "my_server:/srv/http/my_site", "ssh my_server_db" took me to my_server and opened mysql, etc.

nkuttler 13y ago

There are two things I find odd about this solution. You still have to type the path you want to cd to. See previous discussion at https://news.ycombinator.com/item?id=6229001 https://news.ycombinator.com/item?id=6229001 for possible solutions. The github example specifies the username to ssh to. Assuming you ssh to the host more than once see man ssh_config and the User parameter. And screen/tmux, obviously.

vladimirralev 13y ago

It would be much more useful if you can make an scp with autocomplete by pressing tab in the terminal. scp root@host:/long(tab)_file_name .

praseodym 13y ago
zsh can do this :)
bencoder 13y ago
That's always worked by default for me on Ubuntu (assuming ssh keys etc)
ChristianBundy 13y ago
Funny you mention it, I actually have this working! (http://i.imgur.com/8VBYDd4.png http://i.imgur.com/8VBYDd4.png) You can check out my dotfiles (https://github.com/christianbundy/dotfiles https://github.com/christianbundy/dotfiles), but I'm pretty sure that the functionality came standard with one of my Zsh submodules, Prezto (https://github.com/sorin-ionescu/prezto https://github.com/sorin-ionescu/prezto).

jedanbik 13y ago

I think it's a cool exploration. Thanks for sharing.

ChristianBundy 13y ago
Thanks for the sincere comment! I hope you have a kickass Wednesday.

kijin 13y ago

Even better: make the script work with local paths as well. Then you can put alias cd='sshcd' in your .bashrc, and you won't have to distinguish between local and remote paths ever again.

ChristianBundy 13y ago
I was thinking about aliasing cd like that and instead having psuedo-directories that you can cd into to SSH into another box. The biggest problem though would be moving around in the box, as `cd ..` wouldn't take you back to your local machine. What do you think?
- crnixon 13y ago
  Take a look at https://github.com/spencertipping/cd https://github.com/spencertipping/cd. It will let you cd to local or remote machines the same way, and will take you back to your local machine on "cd ..". (It mounts the remote fs instead of SSHing there.)

niklasber 13y ago

Any benefits with this over running something like this? Other than it being shorter and easier for someone not familiar with console commands? ssh -t yourserver.com 'cd /some/dir/;exec /bin/sh'

tostada 13y ago
Doesn't look like it.
ChristianBundy 13y ago
Nope, that's actually very close to what it does. I didn't develop this because the keystrokes were difficult, I just know that both git and SCP support this syntax and couldn't think of any good reason why SSH shouldn't.

pskocik 13y ago

A pretty cool improvement. And you can easily add remote directory autocompletion if you simply steal the autocompletion function of `scp`: complete|sed -n 's/ scp$/ sshcd/p'

neoteric 13y ago

For what it's worth, this is broken when the target directory contains spaces/wildcard characters, etc. I would suggest you consider using something like the following to generate the command line you pass to ssh: printf -v cmd 'cd %q && $SHELL -l' "$target_dir" Also, dropping the ':' and just having an additional argument would make your life a bit simpler. What's with the array assignment just to invoke the command? Seems a bit unnecessary. The microoptimizer in me tells me you should use 'exec' as well :).

ahassan 13y ago

What shell and theme is he using?

ChristianBundy 13y ago
I'm using Zsh with Prezto (https://github.com/sorin-ionescu/prezto https://github.com/sorin-ionescu/prezto), a fork of oh-my-zsh.

rjzzleep 13y ago

a version that works inside your zsh scripts. there may be a better way to do it t=${@[$#]} c=("ssh" "-t" "${@:1:$(( $# -1 ))}" "${t%:}" "cd ${t##:}; \$SHELL -l") "${c[@]}"