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<div class="fish_left_bar fish_left_medium">
        <div class="tutorial_nav">
          <ul class="nav no_shadow">
                <li><a href="#tut_why_fish"><span class="chevron">&rsaquo;</span> Why fish?</a></li>
                <li><a href="#tut_learning_Fish"><span class="chevron">&rsaquo;</span> Learning fish</a></li>
                <li><a href="#tut_running_commands"><span class="chevron">&rsaquo;</span> Running Commands</a></li>
                <li><a href="#tut_getting_help"><span class="chevron">&rsaquo;</span> Getting Help</a></li>
                <li><a href="#tut_syntax_highlighting"><span class="chevron">&rsaquo;</span> Syntax Highlighting</a></li>
                <li><a href="#tut_wildcards"><span class="chevron">&rsaquo;</span> Wildcards</a></li>
                <li><a href="#tut_pipes_and_redirections"><span class="chevron">&rsaquo;</span> Pipes and Redirections</a></li>
                <li><a href="#tut_autosuggestions"><span class="chevron">&rsaquo;</span> Autosuggestions</a></li>
                <li><a href="#tut_tab_completions"><span class="chevron">&rsaquo;</span> Tab Completions</a></li>
                <li><a href="#tut_variables"><span class="chevron">&rsaquo;</span> Variables</a></li>
                <li><a href="#tut_exit_status"><span class="chevron">&rsaquo;</span> Exit Status</a></li>
                <li><a href="#tut_exports"><span class="chevron">&rsaquo;</span> Shell Variables</a></li>
                <li><a href="#tut_lists"><span class="chevron">&rsaquo;</span> Lists</a></li>
                <li><a href="#tut_command_substitutions"><span class="chevron">&rsaquo;</span> Command Substitutions</a></li>
                <li><a href="#tut_combiners"><span class="chevron">&rsaquo;</span> Combiners (And, Or, Not)</a></li>
                <li><a href="#tut_conditionals"><span class="chevron">&rsaquo;</span> Conditionals (If, Else, Switch)</a></li>
                <li><a href="#tut_functions"><span class="chevron">&rsaquo;</span> Functions</a></li>
                <li><a href="#tut_loops"><span class="chevron">&rsaquo;</span> Loops</a></li>
                <li><a href="#tut_prompt"><span class="chevron">&rsaquo;</span> Prompt</a></li>
                <li><a href="#tut_startup"><span class="chevron">&rsaquo;</span> Startup</a></li>
          </ul>
        </div>
</div>

<div class="fish_right_bar fish_right_medium">

<h1 class="interior_title">fish tutorial</h1>

<h2 id="tut_why_fish">Why fish?</h2>

<p>fish is a fully-equipped command line shell (like bash or zsh) that is smart and user-friendly. fish supports powerful features like syntax highlighting, autosuggestions, and tab completions that just work, with nothing to learn or configure.

<p>If you want to make your command line more productive, more useful, and more fun, without learning a bunch of arcane syntax and configuration options, then fish might be just what you're looking for!

<h2 id="tut_learning_Fish">Learning fish</h2>

<p>This tutorial assumes a basic understanding of command line shells and Unix commands, and that you have a working copy of fish.

<p>If you have a strong understanding of other shells, and want to know what fish does differently, search for the magic phrase <i>unlike other shells</i>, which is used to call out important differences.

<p>When you start fish, you should see this:

<pre>
Welcome to fish, the friendly interactive shell
Type <em>help</em> for instructions on how to use fish
you@hostname <em>~</em>>
</pre>

<p>fish comes with a default prompt that shows your username, hostname, and working directory. You'll see <a href="#tut_prompt">how to change your prompt</a> further down. From now on, we'll pretend your prompt is just a '>' to save space.

<h2 id="tut_running_commands">Running Commands</h2>

<p>fish runs commands like other shells: you type a command, followed by its arguments. Spaces are separators:

<pre>
> <b>echo</b> <i>hello world</i>
hello world
</pre>

You can include a literal space in an argument with a backslash, or by using single or double quotes:

<pre>
> <b>mkdir</b> <i>My\ Files</i>
> <b>cp</b> <i>~/Some\ File</i> <i class=quote>'My Files'</i>
> <b>ls</b> <i class=quote>"My Files"</i>
Some File
</pre>

Commands can be chained with semicolons.

<h2 id="tut_getting_help">Getting Help</h2>

fish has excellent help and man pages. Run <tt>help</tt> to open help in a web browser, and <tt>man</tt> to open it in a man page. You can also ask for help with a specific command, for example, <tt>help set</tt> to open in a web browser, or <tt>man set</tt> to see it in the terminal.

<pre>
> <b>man</b> <i>set</i>
set - handle shell variables
  Synopsis...
</pre>

<h2 id="tut_syntax_highlighting">Syntax Highlighting</h2>
You'll quickly notice that fish performs syntax highlighting as you type. Invalid commands are colored red by default:

<pre>
> <b class="error">/bin/mkd</b>
</pre>

A command may be invalid because it does not exist, or refers to a file that you cannot execute. When the command becomes valid, it is shown in a different color:

<pre>
> <b>/bin/mkdir</b>
</pre>

fish will underline valid file paths as you type them:

<pre>
> <b>cat</b> <i><span style="text-decoration: underline">~/somef<u>i</u></span></i>
</pre>

<p>This tells you that there exists a file that starts with '<tt>somefi</tt>', which is useful feedback as you type.

<p>These colors, and many more, can be changed by running <tt>fish_config</tt>, or by modifying variables directly.

<h2 id="tut_wildcards">Wildcards</h2>

fish supports the familiar wildcard *. To list all JPEG files:

<pre>
> <b>ls</b> <i>*.jpg</i>
lena.jpg
meena.jpg
santa maria.jpg
</pre>

<p>You can include multiple wildcards:

<pre>
> <b>ls</b> <i>l*.p*</i>
lena.png
lesson.pdf
</pre>

<p>Especially powerful is the <i>recursive wildcard</i> ** which searches directories recursively:

<pre>
> <b>ls</b> <i>/var/**.log</i>
/var/log/system.log
/var/run/sntp.log
</pre>

<p>If that directory traversal is taking a long time, you can Control-C out of it.

<h2 id="tut_pipes_and_redirections">Pipes and Redirections</h2>

<p>You can pipe between commands with the usual vertical bar:

<pre>
> <b>echo</b> <i>hello world</i> | <b>wc</b>
           1       2      12
</pre>

<p>stdin and stdout can be redirected via the familiar &lt; and &gt;. Unlike other shells, stderr is redirected with a caret ^

<pre>
> <b>grep</b> <i>fish</i> &lt; /etc/shells > ~/output.txt ^ ~/errors.txt
</pre>

<h2 id="tut_autosuggestions">Autosuggestions</h2>

fish suggests commands as you type, and shows the suggestion to the right of the cursor, in gray. For example:

<pre>
> <b class="error">/bin/h</b><span class="suggest"><u>o</u>stname</span>
</pre>

It knows about paths and options:

<pre>
> <b>grep</b> <i>--i<span class="suggest"><u>g</u>nore-case</span></i>
</pre>

And history too. Type a command once, and you can re-summon it by just typing a few letters:

<pre>
> <b>r</b><span class="suggest"><u>s</u>ync -avze ssh . myname@somelonghost.com:/some/long/path/doo/dee/doo/dee/doo</span>
</pre>

To accept the autosuggestion, hit right arrow or Control-F. To accept a single word of the autosuggestion, hit Alt+right arrow. If the autosuggestion is not what you want, just ignore it.

<h2 id="tut_tab_completions">Tab Completions</h2>

<p>fish comes with a rich set of tab completions, that work "out of the box."

<p>Press tab, and fish will attempt to complete the command, argument, or path:

<pre>
> <b class="error">/pri</b><span class="meta">&lt;tab&gt; &rarr;</span> <b>/private/</b>
</pre>

<p>If there's more than one possibility, it will list them:
<pre>
> <b class="error">~/stuff/s</b><span class="meta">&lt;tab&gt;</span>
<i>~/stuff/s</i>cript.sh  <i class="quote">(Executable, 4.8kB)</i>  <i>~/stuff/s</i>ources/  <i class="quote">(Directory)</i>
</pre>

<p>Hit tab again to cycle through the possibilities.

<p>fish can also complete many commands, like git branches:

<pre>
> <b>git</b> <i>merge pr</i><span class="meta">&lt;tab&gt; &rarr;</span> git merge prompt_designer
> <b>git</b> <i>checkout b</i><span class="meta">&lt;tab&gt;</span>
<i>b</i>uiltin_list_io_merge  <i class="quote">(Branch)</i>  <i>b</i>uiltin_set_color  <i class="quote">(Branch)</i>  <i>b</i>usted_events  <i class="quote">(Tag)</i>
</pre>

Try hitting tab and see what fish can do!

<h2 id="tut_variables">Variables</h2>

<p>Like other shells, a dollar sign performs <i>variable substitution</i>:

<pre>
> <b>echo</b> <i>My home directory is $HOME</i>
My home directory is /home/tutorial
</pre>

Variable substitution also occurs in double quotes, but not single quotes:

<pre>
> <b>echo</b> <i class="quote">"My current directory is </i><i>$</i><i class="quote">PWD"</i>
My current directory is /home/tutorial
> <b>echo</b> <i class="quote">'My current directory is $PWD'</i>
My current directory is $PWD
</pre>

Unlike other shells, fish has no dedicated syntax for setting variables. Instead it has an ordinary command: <tt>set</tt>, which takes a variable name, and then its value.

<pre>
> <b>set</b> <i>name</i> <i class="quote">'Mister Noodle'</i>
> <b>echo</b> <i>$name</i>
Mister Noodle
</pre>

<p>(Notice the quotes: without them, <tt>Mister</tt> and <tt>Noodle</tt> would have been separate arguments, and <tt>$name</tt> would have been made into a <i>list</i> of two elements.)

<p>Unlike other shells, variables are <i>not</i> further split after substitution:

<pre>
> <b>mkdir</b> <i>$name</i>
> <b>ls</b>
Mister Noodle
</pre>

In bash, this would have created two directories "Mister" and "Noodle". In fish, it created only one: the variable had the value "Mister Noodle", so that is the argument that was passed to <span style="mono">mkdir</span>, spaces and all.

<h2 id="tut_exit_status">Exit Status</h2>

Unlike other shells, fish stores the exit status of the last command in <tt>$status</tt> instead of <tt>$?</tt>.

<pre>
> <b>false</b>
> <b>echo</b> <i>$status</i>
1
</pre>

Zero is considered success, and non-zero is failure.

<h2 id="tut_exports">Exports (Shell Variables)</h2>

Unlike other shells, fish does not have an export command. Instead, a variable is exported via an option to <tt>set</tt>, either <tt>--export</tt> or just <tt>-x</tt>.

<pre>
> <b>set</b> <i>-x MyVariable SomeValue</i>
> <b>env</b> | <b>grep</b> <i>MyVariable</i>
<span style="background: #A0A">MyVariable</span>=SomeValue
</pre>

You can erase a variable with <tt>-e</tt> or <tt>--erase</tt>
<pre>
> <b>set</b> <i>-e MyVariable</i>
> <b>env</b> | <b>grep</b> <i>MyVariable</i>
<span class="meta">(no output)</span>
</pre>

<h2 id="tut_lists">Lists</h2>

<p>The <tt>set</tt> command above used quotes to ensure that <tt>Mister Noodle</tt> was one argument. If it had been two arguments, then <tt>name</tt> would have been a <i>list</i> of length 2.  In fact, all variables in fish are really lists, that can contain any number of values, or none at all.

<p>Some variables, like <tt>$PWD</tt>, only have one value. By convention, we talk about that variable's value, but we really mean its <i>first</i> (and only) value.

<p>Other variables, like <tt>$PATH</tt>, really do have multiple values. During <i>variable expansion</i>, the variable expands to become multiple arguments:

<pre>
> <b>echo</b> <i>$PATH</i>
/usr/bin /bin /usr/sbin /sbin /usr/local/bin
</pre>

<p>Lists cannot contain other lists: there is no recursion.  A variable is a list of strings, full stop.

<p>Get the length of a list with <tt>count</tt>:

<pre>
> <b>count</b> <i>$PATH</i>
5
</pre>

You can append (or prepend) to a list by setting the list to itself, with some additional arguments. Here we append /usr/local/bin to $PATH:

<pre>
> <b>set</b> <i>PATH $PATH /usr/local/bin</i>
</pre>


You can access individual elements with square brackets. Indexing starts at 1 from the beginning, and -1 from the end:
<pre>
> <b>echo</b> <i>$PATH</i>
/usr/bin /bin /usr/sbin /sbin /usr/local/bin
> <b>echo</b> <i>$PATH[1]</i>
/usr/bin
> <b>echo</b> <i>$PATH[-1]</i>
/usr/local/bin
</pre>

You can also access ranges of elements, known as "slices:"

<pre>
> <b>echo</b> <i>$PATH[1..2]</i>
/usr/bin /bin
> <b>echo</b> <i>$PATH[-1..2]</i>
/usr/local/bin /sbin /usr/sbin /bin
</pre>

You can iterate over a list (or a slice) with a <i>for loop</i>:

<pre>
> <b>for</b> <i>val</i> <b>in</b> <i>$PATH</i>
        <b>echo</b> <i>"entry: $val"</i>
  <b>end</b>
entry: /usr/bin/
entry: /bin
entry: /usr/sbin
entry: /sbin
entry: /usr/local/bin
</pre>


<h2 id="tut_command_substitutions">Command Substitutions</h2>

Command substitutions use the output of one command as an argument to another. Unlike other shells, fish does not use backticks ` for command substitutions. Instead, it uses parentheses:

<pre>
> <b>echo</b> <i>In (</i><b>pwd</b><i>), running (</i><b>uname</b><i>)</i>
In /home/tutorial, running FreeBSD
</pre>

A common idiom is to capture the output of a command in a variable:

<pre>
> <b>set</b> <i>os (</i><b>uname</b><i>)</i>
> <b>echo</b> <i>$os</i>
Linux
</pre>

Command substitutions are not expanded within quotes. Instead, you can temporarily close the quotes, add the command substitution, and reopen them, all in the same argument:

<pre>
> <b>touch</b> <i class="quote">"testing_"</i><i>(</i><b>date</b> <i>+%s</i><i>)</i><i class="quote">".txt"</i>
> <b>ls</b> <i>*.txt</i>
testing_1360099791.txt
</pre>

<h2 id="tut_combiners">Combiners (And, Or, Not)</h2>

Unlike other shells, fish does not have special syntax like &amp;&amp; or || to combine commands. Instead it has commands <tt>and</tt>, <tt>or</tt>, and <tt>not</tt>.

<pre>
> <b>cp</b> <i>file1.txt file1_bak.txt</i>; <b>and echo</b> <i class="quote">"Backup successful"</i>; <b>or echo</b> <i class="quote">"Backup failed"</i>
Backup failed
</pre>

<h2 id="tut_conditionals">Conditionals (If, Else, Switch)</h2>

Use <tt>if</tt>, <tt>else if</tt>, and <tt>else</tt> to conditionally execute code, based on the exit status of a command.

<pre>
<b>if grep</b> <i>fish /etc/shells</i>
        <b>echo</b> <i>Found fish</i>
<b>else if grep</b> <i>bash /etc/shells</i>
        <b>echo</b> <i>Found bash</i>
<b>else</b>
        <b>echo</b> <i>Got nothing</i>
<b>end</b>
</pre>

There is also a <tt>switch</tt> command:

<pre>
<b>switch</b> <i>(</i><b>uname</b><i>)</i>
        <b>case</b> <i>Linux</i>
                <b>echo</b> <i>Hi Tux!</i>
        <b>case</b> <i>Darwin</i>
                <b>echo</b> <i>Hi Hexley!</i>
        <b>case</b> <i>FreeBSD NetBSD DragonFly</i>
                <b>echo</b> <i>Hi Beastie!</i>
        <b>case</b> <i class="quote">'*'</i>
                <b>echo</b> <i>Hi, stranger!</i>
<b>end</b>
</pre>

Note that <tt>case</tt> does not fall through, and can accept multiple arguments or (quoted) wildcards.

<h2 id="tut_functions">Functions</h2>

A fish function is a list of commands, which may optionally take arguments. Unlike other shells, arguments are not passed in "numbered variables" like <tt>$1</tt>, but instead in a single list <tt>$argv</tt>. To create a function, use the <tt>function</tt> builtin:

<pre>
> <i><b>function</b> say_hello
         <b>echo</b> Hello $argv
  <b>end</b></i>
> <b>say_hello</b>
Hello
> <b>say_hello <i>everybody!</i></b>
Hello everybody!
</pre>

<p>Unlike other shells, fish does not have aliases or special prompt syntax. Functions take their place.

<p>You can list the names of all functions with the <tt>functions</tt> keyword (note the plural!). fish starts out with a number of functions:

<pre>
> <b>functions</b>
alias, cd, delete-or-exit, dirh, dirs, down-or-search, eval, export, fish_command_not_found_setup, fish_config, fish_default_key_bindings, fish_prompt, fish_right_prompt, fish_sigtrap_handler, fish_update_completions, funced, funcsave, grep, help, history, isatty, ls, man, math, nextd, nextd-or-forward-word, open, popd, prevd, prevd-or-backward-word, prompt_pwd, psub, pushd, seq, setenv, sgrep, trap, type, umask, up-or-search, vared
</pre>

<p>You can see the source for any function by passing its name to <tt>functions</tt>:

<pre>
> <b>functions</b> <i>ls</i>
function ls --description 'List contents of directory'
        command ls -G $argv
end
</pre>

<h2 id="tut_loops">Loops</h2>

While loops:

<pre>
> <b>while</b> <i>true</i>
        <b>echo</b> <i class="quote">"Loop forever"</i>
<b>end</b>
Loop forever
Loop forever
Loop forever
...
</pre>

For loops can be used to iterate over a list. For example, a list of files:

<pre>
> <b>for</b> <i>file in *.txt</i>
        <b>cp</b> <i>$file $file.bak</i>
<b>end</b>
</pre>

Iterating over a list of numbers can be done with `seq`:

<pre>
> <b>for</b> <i>x in (</i><b>seq</b> <i>5)</i>
        <b>touch</b> <i>file_$x.txt</i>
<b>end</b>
</pre>


<h2 id="tut_prompt">Prompt</h2>

Unlike other shells, there is no prompt variable like PS1. To display your prompt, fish executes a function with the name <tt>fish_prompt</tt>, and its output is used as the prompt.

You can define your own prompt:
<pre>
> <b>function <i>fish_prompt</i>
        echo <i>"New Prompt % "</i>
  end</b>
New Prompt % <u> </u>
</b>
</pre>

Multiple lines are OK. Colors can be set via <tt>set_color</tt>, passing it named ANSI colors, or hex RGB values:

<pre>
> <b>function</b> <i>fish_prompt</i>
        <b>set_color</b> <i>purple</i>
        <b>date</b> <i class="quote">"+%m/%d/%y"</i>
        <b>set_color</b> <i>FF0</i>
        <b>echo</b> <i>(</i><b>pwd</b><i>)</i> <i class="quote">'>'</i>
        <b>set_color</b> <i>normal</i>
  <b>end</b>
<span style="color: purple">02/06/13</span>
<span style="color: #FF0">/home/tutorial ></span><u> </u>
</b>
</pre>

<p>You can choose among some sample prompts by running <tt>fish_config prompt</tt>. fish also supports RPROMPT through <tt>fish_right_prompt</tt>.

<h3>$PATH</h2>

<tt>$PATH</tt> is an environment variable containing the directories in which fish searches for commands. Instead of separating entries with a colon, $PATH is a list. You can modify $PATH in a few ways:

<p><ol>
<li>By modifying the <tt>$fish_user_paths</tt> variable, which is automatically appended to <tt>$PATH</tt>. For example, to permanently add /usr/local/bin to your <tt>$PATH</tt>, you could write:

<pre>
> <b>set</b> <i>-U fish_user_paths $fish_user_paths /usr/local/bin</i>
</pre>


<li>Directly in config.fish (see below).</li>
</ol>

<h2 id="tut_startup">Startup (Where's .bashrc?)</h2>

<p>fish starts by executing commands in <tt>~/.config/fish/config.fish</tt>. You can create it if it does not exist.

<p>It is possible to directly create functions and variables in <tt>config.fish</tt> file, using the commands shown above. For example:

<p><pre>
> <b>cat</b> <i>~/.config/fish/config.fish</i>

set -x PATH $PATH /sbin/

function ll
    ls -lh $argv
end
</pre>

<p>However, it is more common and efficient to use  <i>autoloading functions</i> and <i>universal variables</i>.

<h3>Autoloading Functions</h2>

<p>When fish encounters a command, it attempts to <i>autoload</i> a function for that command, by looking for a file with the name of that command in <tt>~/.config/fish/functions/</tt>.

<p>For example, if you wanted to have a function <tt>ll</tt>, you would add a text file <tt>ll.fish</tt> to <tt>~/.config/fish/functions</tt>:

<pre>
> <b>cat</b> <i>~/.config/fish/functions/ll.fish</i>
function ll
        ls -lh $argv
end
</pre>

This is the preferred way to define your prompt as well:

<pre>
> <b>cat</b> <i>~/.config/fish/functions/fish_prompt.fish</i>
function fish_prompt
        echo (pwd) '> '
end
</pre>

<p>See the documentation for <a href="commands.html#funced">funced</a> and <a href="commands.html#funcsave">funcsave</a> for ways to create these files automatically.

<h3>Universal Variables</h2>

<p>A universal variable is a variable whose value is shared across all instances of fish, now and in the future - even after a reboot. You can make a variable universal with <tt>set -U</tt>:

<pre>
> <b>set</b> <i>-U EDITOR vim</i>
</pre>

Now in another shell:

<pre>
> <b>echo</b> <i>$EDITOR</i>
vim
</pre>

<h3>Ready for more?</h2>

<p>If you want to learn more about fish, there is <a href="index.html">lots of detailed documentation</a>, an <a href="https://lists.sourceforge.net/lists/listinfo/fish-users">official mailing list</a>, the IRC channel <tt>#fish</tt> on <tt>irc.oftc.net</tt>, and the <a href="http://github.com/fish-shell/fish-shell/">github page</a>.

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