You can install it using [Homebrew][1]:

    brew install ssh-copy-id

If you don&#39;t want to use Homebrew, you can use [this Mac port](https://github.com/beautifulcode/ssh-copy-id-for-OSX):

    curl -L https://raw.githubusercontent.com/beautifulcode/ssh-copy-id-for-OSX/master/install.sh | sh 

  [1]: https://github.com/homebrew/brew

MacPorts version: `sudo port install openssh +ssh-copy-id`

`ssh-copy-id` is installed on macOS by default now.

    $ sw_vers
    ProductName:	Mac OS X
    ProductVersion:	10.12.4
    
    $ which ssh-copy-id
    /usr/bin/ssh-copy-id

The above methods do not work on old Macs. I have a lion OS. use this instead because the ssh-copy-id can not be installed with brew on old PCs due to compiling dependencies errors at ssl.

    cat ~/.ssh/id_rsa.pub | ssh user@123.45.56.78 &quot;mkdir -p ~/.ssh &amp;&amp; cat &gt;&gt;  ~/.ssh/authorized_keys&quot;

credit goes to [this site][1]


  [1]: https://www.digitalocean.com/community/tutorials/how-to-set-up-ssh-keys--2

install [homebrew][1]
then `$ brew install ssh-copy-id` 


  [1]: http://brew.sh

In Swift, is there any way to check if an index exists in an array without a fatal error being thrown?

I was hoping I could do something like this:

    let arr: [String] = [&quot;foo&quot;, &quot;bar&quot;]
    let str: String? = arr[1]
    if let str2 = arr[2] as String? {
        // this wouldn&#39;t run
        println(str2)
    } else {
        // this would be run
    }

But I get

&gt; fatal error: Array index out of range

Swift Array - Check if an index exists

For whatever reason, the Ruby on Rails console refuses to start; it just hangs. I haven&#39;t made any changes to my code, and other projects using the same version of Ruby and Ruby on Rails have no issue. When I finally &lt;kbd&gt;Ctrl&lt;/kbd&gt; + &lt;kbd&gt;C&lt;/kbd&gt; I get this stack trace, which points to Spring.

I can&#39;t explain why this is happening from one moment to the next, where it was working fine. I have cleared out all the gems through RVM and reinstalled all through bundle command, but still no luck. Any ideas would be appreciated.

Also the Ruby on Rails server has no issue so as far as I can tell. The issue is project related, however no code has changed, and it&#39;s only the Ruby on Rails console that has the issue.

Ruby 2.1.2 &lt;br/&gt;
Rails 4.1.4

    user_a@ubuntu:~/work/app_a$ rails console
    ^C/home/user_a/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/client/run.rb:54:in `gets&#39;: Interrupt
        from /home/user_a/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/client/run.rb:54:in `verify_server_version&#39;
        from /home/user_a/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/client/run.rb:25:in `call&#39;
        from /home/user_a/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/client/command.rb:7:in `call&#39;
        from /home/user_a/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/client/rails.rb:23:in `call&#39;
        from /home/user_a/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/client/command.rb:7:in `call&#39;
        from /home/user_a/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/client.rb:26:in `run&#39;
        from /home/user_a/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/bin/spring:48:in `&lt;top (required)&gt;&#39;
        from /home/user_a/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/binstub.rb:11:in `load&#39;
        from /home/user_a/.rvm/gems/ruby-2.1.2/gems/spring-1.1.3/lib/spring/binstub.rb:11:in `&lt;top (required)&gt;&#39;
        from /home/user_a/work/app_a/bin/spring:16:in `require&#39;
        from /home/user_a/work/app_a/bin/spring:16:in `&lt;top (required)&gt;&#39;
        from bin/rails:3:in `load&#39;
        from bin/rails:3:in `&lt;main&gt;&#39;

    user_a@ubuntu:~/work/app_a$




Ruby on Rails console is hanging when loading

I am having trouble trying to install ssh-copy-id on my Mac. I have tried to follow https://github.com/beautifulcode/ssh-copy-id-for-OSX  but every time I run ssh-copy-id it gives me errors. Any ideas on how to get ssh-copy-id to install?

How do you install ssh-copy-id on a Mac?

<p>I am having trouble trying to install ssh-copy-id on my Mac. I have tried to follow <a href="https://github.com/beautifulcode/ssh-copy-id-for-OSX" target="_blank" rel="noopener noreferrer">https://github.com/beautifulcode/ssh-copy-id-for-OSX</a>  but every time I run ssh-copy-id it gives me errors. Any ideas on how to get ssh-copy-id to install?</p>


pip is not able to install packages correctly: Permission denied error

I know similar questions exist, such as [MySQL with MAMP does not work with OSX Yosemite 10.10][1]. However, I do have MAMP, nor XAMPP installed on my computer.

When I try to start mySQL from the PrefPane, nothing happens.

When I try to start mqSQL from the command line via `sudo /usr/local/mysql/support-files/mysql.server start` I get:  

&gt; `Starting MySQL . ERROR! The server quit without updating PID file`
&gt; `(/usr/local/mysql/data/adamg.local.pid).`

Any and all help would be appreciated. I can supply any file output necessary.

  [1]: https://stackoverflow.com/questions/25333173/mysql-with-mamp-does-not-work-with-osx-yosemite-10-10

MySQL does not start when upgrading OSX to Yosemite or El Capitan

I use postgres from homebrew in my OS X, but when I reboot my system, sometimes the postgres doesn&#39;t start after the reboot, and so I manually tried to start it with `postgres -D /usr/local/var/postgres`, but then the error occurred with the following message: `FATAL:  could not open directory &quot;pg_tblspc&quot;: No such file or directory`.

The last time it occurred, I couldn&#39;t get it to the original state, so I decided to uninstall the whole postgres system and then re-installed it and created users, tables, datasets, etc... It was so disgusting, but it frequently occurs on my system, say once in a few months.

So why does it lose the `pg_tblspc` file frequently? And is there anything that I can do to avoid the loss of the file?

I haven&#39;t upgraded my homebrew and postgres to the latest version (i.e. I&#39;ve been using the same version). Also, all the things that I did on the postgres database is delete the table and populate the new data every day. I haven&#39;t changed the user, password, etc...

EDIT (mbannert): 
I felt the need to add this, since the thread is the top hit on google for this issue and for many the symptom is different. Homebrewers likely will encounter this error message:

    No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket &quot;/tmp/.s.PGSQL.5432&quot;?

So, if you just experienced this after the Yosemite upgrade you now you&#39;re covered for now reading this thread.

`pg_tblspc` missing after installation of latest version of OS X (Yosemite or El Capitan)

I am running Xcode 6 and iOS 8 GM. Every other time I run my app I get this message from Xcode:

&gt; &quot;Could not inspect the application package&quot;

So I can run and build, I will get the message. I run and build again, everything runs as expected (this is to my device). Then it will rinse and repeat, every other time giving me this error.

I have looked at all the other solutions that have been suggested but cannot stop this error. I have cleaned my project, cleaned the build folder, deleted derived data etc with no luck.

How can I see what is causing this in the first place?

Interestingly, this only happens when running on my device. Not on the simulator. Also, it only happens on my device, when building for debug. If I change the scheme to release, I can build and run endlessly without with error. Ideas?

Xcode: Could not inspect the application package

I am running docker and I want `bash` command completion for `docker` commands and parameters.

How to add bash command completion for Docker on Mac OS X?

I have GitLab &amp; GitLab CI set up to host and test some of my private repos. For my composer modules under this system, I have Satis set up to resolve my private packages.

Obviously these private packages require an ssh key to clone them, and I have this working in the terminal - I can run composer install and get these packages, so long as I have the key added with `ssh-add` in the shell.

However, when running my tests in GitLab CI, if a project has any of these dependencies the tests will not complete as my GitLab instance needs authentication to get the deps (obviously), and the test fails saying `Host key verification failed`.

My question is how do I set this up so that when the runner runs the test it can authenticate to gitlab without a password? I have tried putting a password-less ssh-key in my runners `~/.ssh` folder, however the build wont even add the key, &quot;eval `ssh-agent -s`&quot; followed by ssh-add seems to fail saying the agent isn&#39;t running...

Getting GitLab CI to clone private repositories

Problem: frequently the first command I type to my boxes is `su -`.

Question: how do I make `vagrant ssh` use the root user by default?

Version: vagrant 1.6.5

vagrant login as root by default

I kept getting kicked out of my compute engine instance after a few seconds of idle with the indicated error (255).
I used &#39;gcloud compute ssh&#39; to log in.
I am using the default firewall setting, which I believe would be good enough for ssh.
But if I am missing something, please so indicate and suggest the fix for this error.
Basically I can&#39;t get any efficient work done at this point having to ssh in so many times.

ERROR: (gcloud.compute.ssh) [/usr/bin/ssh] exited with return code [255]

I&#39;ve been looking for a solution on how I can use multiple ssh keys and I figured out, that it will work with a config file in the .ssh directory, but it doesn&#39;t work on windows.

My problem is that I&#39;m using a private key to access a git server, so it looks like this:
ssh://git@example.com/directory , it works fine when I&#39;m using TortoiseGit, &#39;cause there is a possibility to choose the private key.

But I want to use the git rep in my IntelliJ IDEA and there is just the option to use the git native shell and it also works, if I put the key, called id_rsa ,into the .ssh folder. Now I want to use multiple ssh keys (so my key will get the name &quot;id_rsa_test&quot;, so how do I configure the .ssh/config file under Windows, that it works with a usual git server?

The most examples I found yet are just for the use with github.


.ssh/config file for windows (git)

This is my first time accessing GitHub and I&#39;m not experienced using a console. I am on a MacBook using Bash. When I try to access GitHub, I get this:

    git clone git@github.com:dhulihan/league-of-legends-data-scraper.git
    Cloning into &#39;league-of-legends-data-scraper&#39;...
    Permission denied (publickey).
    fatal: Could not read from remote repository.
    
    Please make sure you have the correct access rights
    and the repository exists.

I&#39;ve tried following the instructions on Github page about permission being denied.

When I use `ssh -vT git@github.com`, I get the following:

    OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011
    debug1: Reading configuration data /etc/ssh_config
    debug1: /etc/ssh_config line 20: Applying options for *
    debug1: Connecting to github.com [192.30.252.129] port 22.
    debug1: Connection established.
    debug1: identity file /Users/XXXX/.ssh/id_rsa type -1
    debug1: identity file /Users/XXXX/.ssh/id_rsa-cert type -1
    debug1: identity file /Users/XXXX/.ssh/id_dsa type -1
    debug1: identity file /Users/XXXX/.ssh/id_dsa-cert type -1
    debug1: Enabling compatibility mode for protocol 2.0
    debug1: Local version string SSH-2.0-OpenSSH_6.2
    debug1: Remote protocol version 2.0, remote software version libssh-0.6.0
    debug1: no match: libssh-0.6.0
    debug1: SSH2_MSG_KEXINIT sent
    debug1: SSH2_MSG_KEXINIT received
    debug1: kex: server-&gt;client aes128-ctr hmac-sha1 none
    debug1: kex: client-&gt;server aes128-ctr hmac-sha1 none
    debug1: sending SSH2_MSG_KEXDH_INIT
    debug1: expecting SSH2_MSG_KEXDH_REPLY
    debug1: Server host key: RSA 16:27:ac:a5:76:28:2d:36:63:1b:56:4d:eb:df:a6:48
    debug1: Host &#39;github.com&#39; is known and matches the RSA host key.
    debug1: Found key in /Users/XXXX/.ssh/known_hosts:1
    debug1: ssh_rsa_verify: signature correct
    debug1: SSH2_MSG_NEWKEYS sent
    debug1: expecting SSH2_MSG_NEWKEYS
    debug1: SSH2_MSG_NEWKEYS received
    debug1: Roaming not allowed by server
    debug1: SSH2_MSG_SERVICE_REQUEST sent
    debug1: SSH2_MSG_SERVICE_ACCEPT received
    debug1: Authentications that can continue: publickey
    debug1: Next authentication method: publickey
    debug1: Trying private key: /Users/XXXX/.ssh/id_rsa
    debug1: Trying private key: /Users/XXXX/.ssh/id_dsa
    debug1: No more authentication methods to try.
    Permission denied (publickey).

Next, `eval &quot;$(ssh-agent -s)&quot;` returns &quot;Agent pid 2314&quot;,
however `ssh-add -l` returns &quot;The agent has no identities.&quot;

And that is where I am stuck. 

Github permission denied: ssh add agent has no identities

I installed Wireshark on my mac with the command

    brew install wireshark

but after that, a message told me that I had to _curl_ and install _ChmodBPF_, so I did that too. 

But there is no command named Wireshark on terminal. What is wrong with that?

Install Wireshark on MacOS X via brew

When I run `brew doctor`, the following error is thrown

    Warning: Unbrewed header files were found in /usr/local/include.
    If you didn&#39;t put them there on purpose they could cause problems when
    building Homebrew formulae, and may need to be deleted.
    
    Unexpected header files:
        /usr/local/include/curl/curl.h
        /usr/local/include/curl/curlbuild.h
        /usr/local/include/curl/curlrules.h
        /usr/local/include/curl/curlver.h
        /usr/local/include/curl/easy.h
        /usr/local/include/curl/mprintf.h
        /usr/local/include/curl/multi.h
        /usr/local/include/curl/stdcheaders.h
        /usr/local/include/curl/typecheck-gcc.h
        /usr/local/include/node/ares.h
        /usr/local/include/node/ares_version.h
        /usr/local/include/node/nameser.h
        /usr/local/include/node/node.h
        /usr/local/include/node/node_buffer.h
        /usr/local/include/node/node_internals.h
        /usr/local/include/node/node_object_wrap.h
        /usr/local/include/node/node_version.h
        /usr/local/include/node/openssl/opensslconf.h
        /usr/local/include/node/uv-private/ngx-queue.h
        /usr/local/include/node/uv-private/stdint-msvc2008.h
        /usr/local/include/node/uv-private/tree.h
        /usr/local/include/node/uv-private/uv-bsd.h
        /usr/local/include/node/uv-private/uv-darwin.h
        /usr/local/include/node/uv-private/uv-linux.h
        /usr/local/include/node/uv-private/uv-sunos.h
        /usr/local/include/node/uv-private/uv-unix.h
        /usr/local/include/node/uv-private/uv-win.h
        /usr/local/include/node/uv.h
        /usr/local/include/node/v8-debug.h
        /usr/local/include/node/v8-preparser.h
        /usr/local/include/node/v8-profiler.h
        /usr/local/include/node/v8-testing.h
        /usr/local/include/node/v8.h
        /usr/local/include/node/v8stdint.h
        /usr/local/include/node/zconf.h
        /usr/local/include/node/zlib.h

Would it be safe to delete these files? What is the optimal way to resolve this warning?‏‏‏‏‏‏


Brew doctor - &quot;warning: unbrewed header files were found in /usr/local/include&quot;?

### How to install/enable __php-gd__ and __mcrypt__ in Yosemite 10.10 - PHP 5.5.14 build?

_note that following steps install newest PHP 5.5.x_

To check if you have gd and mcrypt installed use `$ php -m` to display compiled in modules, continue if you are missing desired modules and please see __[accepted answer][1]__. 

----
## GD

&gt; So, Apple installed GD (and you&#39;re using their build of PHP, which is fine), but did not include support for PNG.

You are definitely missing &quot;full&quot; __gd (with png support)__ module if: 
[imagecreatefrompng()](http://php.net/manual/en/function.imagecreatefrompng.php) function is missing.

`&quot;Call to undefined function imagecreatefrompng()&quot;`

![enter image description here][2]


---
## Mcrypt

install brew using __[accepted answer][1]__ and omit part with gd installation (unless you need it), and use following steps:


  1. do search - `$ brew search mcrypt`
  2. pick the version of PHP you want
  3. install - `$ brew install php55-mcrypt`
  4. confirm using `$ php -m | grep mcrypt`


  [1]: https://stackoverflow.com/a/26505558/1564365
  [2]: http://i.stack.imgur.com/0RAJY.png

---
## Want to switch between PHP versions? 

Check out [brew-php-switcher](https://github.com/philcook/brew-php-switcher) and follow instructions.

Yosemite / El Capitan php-gd + mcrypt installation

While installing `tig`, `HomeBrew` is displaying the following issues while installing a dependency:

    Error: The `brew link` step did not complete successfully
    The formula built, but is not symlinked into /usr/local
    Could not symlink bin/a2x
    /usr/local/bin is not writable.
    
    You can try again using:
      brew link asciidoc

Homebrew: Could not symlink, /usr/local/bin is not writable

Can someone explain this to me please and what I can do to sort out my permissions issue. It seems to be stopping me from getting the authenticity of host `heroku` and fixing my keys issues.

```
david@daniel-Inspiron-531:~$ ssh-add david/.ssh/id_rsa
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Permissions 0775 for &#39;david/.ssh/id_rsa&#39; are too open.
It is required that your private key files are NOT accessible by others.
This private key will be ignored.
david@daniel-Ins
```

Getting &quot;Warning: unprotected private key file!&quot; error message while attempting to import SSH key



    $ git remote add origin git@github.com:lut/EvolutionApp.git
    fatal: remote origin already exists.

    $ git push -u origin master
    fatal: &#39;EvolutionApp&#39; does not appear to be a git repository
    fatal: Could not read from remote repository.

    Please make sure you have the correct access rights
    and the repository exists.

My keys were added succesfully

     $ ssh -T git@github.com
     Hi lut! You&#39;ve successfully authenticated, but GitHub does not provide shell access.

The Github article https://help.github.com/articles/generating-ssh-keys/ says that &quot;Shell access&quot; should not be an issue? What could the problem be?



Github Authentication Failed - ... GitHub does not provide shell access

It&#39;s failed when I used Git command &quot;git pull&quot; to update my repository, messages as below:
fatal: unable to access &#39;...&#39;: Empty reply from server. 

And the I tried to use the GitHub App, but alert this: 

    Cloning into &#39;renren_mobile&#39;...
    warning: templates not found /Applications/GitHub.app/Contents/Resources/git/templates
    2014-11-23 13:58:57.975 GitHub for Mac Login[659:11891] AskPass with arguments: (
        &quot;/Applications/GitHub.app/Contents/MacOS/GitHub for Mac Login&quot;,
        &quot;Username for &#39;https://github.com&#39;: &quot;
    )
    2014-11-23 13:58:58.032 GitHub for Mac Login[660:11915] AskPass with arguments: (
        &quot;/Applications/GitHub.app/Contents/MacOS/GitHub for Mac Login&quot;,
        &quot;Password for &#39;&#39;: &quot;
    )
    fatal: unable to access &#39;...&#39;: Empty reply from server
     (128)

How to resolve &quot;git pull,fatal: unable to access &#39;https://github.com...\&#39;: Empty reply from server&quot;

I created a new instance via the Google Cloud web console from a CentOS 6.x image. I saw a blank on the creation form where I could paste in an existing SSH key; since this was my first instance, I didn&#39;t have one yet. I assumed it would take me through the key creation process like Amazon EC2 does. It didn&#39;t.

The instance appears to be created, but I can&#39;t figure out how to get the SSH key for it. The instance web page has a button that says &quot;SSH&quot; and it let me log in briefly via a pop-up web browser window that simulates an SSH session. However, it only let me into a user-level account, not `root`. The pop-up had a menu item to change the user and changing it to `root` does nothing but generate connection errors.  Now I can&#39;t log into my instance at all!

I&#39;ve searched but can&#39;t find any straight-forward documentation that explains this aspect of Google Compute instances.

Do I have to create my own SSH keys manually and paste them into the form during instance creation?  Is there an obvious step I&#39;m missing?


How to access SSH keys for a Google Cloud Platform Compute Engine VM instance?

I have been developing an Ansible playbook for a couple of weeks, therefore, my experience with such technology is relatively short. Part of my strategy includes using a custom &lt;code&gt;ansible_ssh_user&lt;/code&gt; for provisioning hosts throughout the inventory, however, such user will need its own SSH key pair, which would involve some sort of a plan for holding/storing its correspondent private key. On a production environment, this playbook would be cloned/pulled and run inside a certain *playbook node* whose role is to provision the rest of the infrastructure.

At first, I was thinking to just put that private key inside the playbook git repository, but I am having second thoughts about it nonetheless, mostly because of somewhat obvious security reasons and common sense around it, hence the reason I need to consult you about this matter. 

With this set on the table, here are the follow-up questions:

* In an Ansible-based development environment, is it sane/reasonable to hold a private SSH key in source control?
* Would this practice be advised *only for development environments* whereas another local git branch inside the *playbook node* would be then used to hold the actual production SSH private key?
* Would it be better to address this case scenario via Ansible Vault instead?, I have not ever used this before, but regardless of that I cannot yet tell whether this would be a proper case for using it.
* In your experience, what would be your approach around this in a production environment?, what would it be considered as the best practice in this particular scenario?

Content Type	Original Author	Original Content on Stackoverflow
Question	Technic1an	View Question on Stackoverflow
Solution 1 - Macos	nwinkler	View Answer on Stackoverflow
Solution 2 - Macos	Victor Sergienko	View Answer on Stackoverflow
Solution 3 - Macos	Ryan	View Answer on Stackoverflow
Solution 4 - Macos	Sherif O.	View Answer on Stackoverflow
Solution 5 - Macos	vikrantt	View Answer on Stackoverflow

How do you install ssh-copy-id on a Mac?

Macos Problem Overview

Macos Solutions

Solution 1 - Macos

Solution 2 - Macos

Solution 3 - Macos

Solution 4 - Macos

Solution 5 - Macos

Ruby on Rails console is hanging when loading

Swift Array - Check if an index exists

Attributions