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I can't find a way to pass output of whereis command to cd command in same line so I don't have to do cd in the second step.

I have tried passing like below:

cd $(whereis node_modules)

Or

cd "`dirname $(whereis node_modules)`"

Also

cd "$(whereis node_modules)"

But none of the above method works.

Can somebody find what should be wrong in above codes ?

Rui F Ribeiro
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Vicky Dev
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4 Answers4

6

This appears to do the trick:

cd "$(dirname "$(whereis node_modules)")"

If, as per your comment, you want to go into the target if it is a directory:

location=$(whereis node_modules)
if [[ -d "$location" ]]; then
    cd "$location"
else
    cd "$(dirname "$location" )"
fi

The above could easily be made into a function in your .bash_profile.

dhag
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DopeGhoti
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  • Nope, sorry it doesn't work, doing `whereis node_modules` gives me path `/usr/local/lib/node_modules` but doing `cd` like you did doesn't put me in that directory path. – Vicky Dev Jun 17 '16 at 04:45
  • Try `cd $(dirname $(whereis node_modules | cut -d' ' -f2) )` – John1024 Jun 17 '16 at 05:08
  • Very close, but it goes to `/usr/local/lib` but stays out of `node_modules`. – Vicky Dev Jun 17 '16 at 05:11
  • That's because the command I gave you (for which you asked) goes to the directory in which the specified thing you searched for resides. `ls` is at `/bin/ls`, so `cd $(dirname $(whereis ls) )` will resolve to `cd /bin`. I will adjust my answer to go into a directory if that is what you have specified. – DopeGhoti Jun 17 '16 at 05:35
  • @DopeGhoti, many thanks to you for suggesting an alternate way. Can you post links for how to create function in `.bash_profile` in your answer ? – Vicky Dev Jun 17 '16 at 05:42
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    @VickyDev [this](http://unix.stackexchange.com/questions/106601/how-to-add-a-function-to-bash-profile-profile-bashrc-in-shell) will surely help you. – Rahul Jun 17 '16 at 06:26
6

You can do that with,

cd "`which node_modules`"

With dirname to get the directory:

cd "$(dirname "$(which node_modules)" )"

as you have mentioned in the comment I am expecting to do this in one step & assuming nod_module is a directory, so you can do that with the following command:

cd $(whereis node_modules | cut -d ' ' -f2)

(Note that the latter command assumes that the Linux whereis is being used, not the BSD one, and that the path does not contain any spaces.)

As suggested by @Dani_I, you can have a look at this Why not use "which"? What to use then?, which might be more useful.

Community
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Rahul
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  • No, these doesn't work either, `cd $(which node_modules | xargs dirname)` gives me `missing operand` error. – Vicky Dev Jun 17 '16 at 04:47
  • @VickyDev are you sure ? I tested same command replacing `node_modules` with `find` and it `cd` to dir – Rahul Jun 17 '16 at 04:50
  • Yes I tried it several times, but it gives me `missing operand` error – Vicky Dev Jun 17 '16 at 04:53
  • `missing operand` means that you specified a command which `which` could not find on your system. Try a different command, one that `which` can locate. – John1024 Jun 17 '16 at 04:54
  • @John1024 as OP have specified `ubuntu` in tag, assuming that, it should have `which` command, what you say ? – Rahul Jun 17 '16 at 05:00
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    @Rahul Yes, I expect that `which` is installed. I don't have node_modules installed but I tried your command for firefox: `cd $(which firefox | xargs dirname)` __and it worked fine__. When I tried it with a bad name, say `cd $(which firefoxx | xargs dirname)` then it returns `missing operand` which is the same error that VickyDev reports. – John1024 Jun 17 '16 at 05:03
  • Doing `which node_modules` give me empty string, but doing `whereis node_modules` gives me `node_modules: /usr/local/lib/node_modules`, so how can I `cd` to that path (removing colon and everything before it) in same step ? – Vicky Dev Jun 17 '16 at 05:05
  • @VickyDev see my updated answer – Rahul Jun 17 '16 at 05:12
  • That works, thanks, so it will work for any `whereis` directory path which have a colon and directory name before it right ?, Generalised ? If yes then I will at-once accept it. – Vicky Dev Jun 17 '16 at 05:14
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    @VickyDev remember `dirname` is used to *strip last component from file name*. so it depends on your system. Because when I use the same command `whereis find` it gives me `find: /usr/bin/find`, but I can't `cd` to `/usr/bin/find` it will give me error like 'No such file' because last component of `whereis` result `find` is not a directory. so I had to use `dirname` along with `cd$(..)` to change directory. – Rahul Jun 17 '16 at 05:18
  • It won't work if there are multiple paths(space delimited), I get that, but it should work if there is only one path location of any component/command/directory, right ? I guess that's about it then. – Vicky Dev Jun 17 '16 at 05:22
  • Oh no, problem is there, I have also installed `bower` it is installed only in one path `/usr/local/bin/bower` but when I use your command like `cd $(whereis bower | cut -d ' ' -f2)` it gives me `bash: cd: /usr/local/bin/bower: Not a directory` error. – Vicky Dev Jun 17 '16 at 05:27
  • @VickyDev at that time you would have to use `cd $(whereis bower | cut -d ' ' -f2 | xargs dirname)` – Rahul Jun 17 '16 at 05:29
  • @VickyDev as I told you, it depends on your system, `dirname` is used to strip last component of path. previous command gave you error because `bower` is not a directory. – Rahul Jun 17 '16 at 05:30
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    @Rahul, got that, thanks a lot, your last answer (the one with `find`) is really re-usable and generalised – Vicky Dev Jun 17 '16 at 05:34
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    you should probably replace `which` with `command -v` and see http://unix.stackexchange.com/questions/85249/why-not-use-which-what-to-use-then – Dani_l Jun 17 '16 at 15:24
4

whereis gives you the pattern name and the location, separated by colon, so performing cd or dirname on whereis result can not work:

$ whereis node_modules
node_modules: /usr/lib/node_modules

The proper method is using npm itself to get its default prefix:

$ cd "$(npm get prefix)/lib/node_modules"
$ pwd
/usr/lib/node_modules
cuonglm
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  • Your answer is good, thanks, but I was expecting to do it in same step, can't we just remove everything before first colon including colon and pass it to `cd`, string operation on the output of command just like in other languages ? – Vicky Dev Jun 17 '16 at 04:59
  • What do you mean *one step*? Is not `cd "$(npm get prefix)/lib/node_modules"` one step only? – cuonglm Jun 17 '16 at 05:00
  • But when I don't know the whole path and just last directory name then how would I use your command ? It's not just about the `node_modules` dir but generalised for any directory in my system – Vicky Dev Jun 17 '16 at 05:01
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    It depends on your tool. Here you want to get to `npm` default modules location, then it's always `npm` prefix + `lib/node_modules`, other tools need other method. – cuonglm Jun 17 '16 at 05:02
0

This works for me. Where is has -q (quite) option, which is just for the purpose of passing result in command line.

cd `whereis -q node_modules`
Zaw
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