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<!doctype html>
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<head>
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<a href="#file-test-operators">File Testing</a>
<a href="#integer-comparison-operators">Integer Comparison</a>
<a href="#string-comparison-operators">String Comparison</a>
<a href="#compound-operators">Compound Operators</a>
<a href="#job-identifiers">Job Identifiers</a>
<a href="#list-constructs">List Constructs</a>
<a href="#reserved-exit-codes">Reserved Exit Codes</a>
<a href="#signals">Signals</a>
<a href="#sending-control-signals">Sending Control Signals</a>
<a href="#file-types">File Types</a>
<a href="#permissions">Permissions</a>
<a href="#string-manipulation">String Manipulation</a>
<a href="#command-parameters">Command Parameters</a>
<a href="#history-expansion">History Expansion</a>
<a href="#variable-operations">Variable Operations</a>
<a href="#bash-globbing">Bash Globbing</a>
<a href="#regular-expressions">Regular Expressions</a>
<a href="#shell-builtins">Shell Builtins</a>
<a href="#overview-of-symbols">Symbol Overview</a>
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<section>
<!-- Operators for comparison could be grouped under a "conditionals" or "testing" tab -->
<div id="super-container" class="container">
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<div class="twelve columns" style="">
<h2 id="gradient-h1" style="">New Website Released</h2>
<p style="background: none; margin-left: auto; margin-right:auto; display: block; width: 50vw; "><a href="https://www.cheatsheet.wtf/bash">Click here to visit the improved website.</a></p>
</div>
<div class="ten columns offset-by-one">
<p class="explanation info-box shadow-box">
For a brand new version of this website, please visit: <a href="https://www.cheatsheet.wtf/bash/">www.Cheatsheet.Wtf</a>. The new website have has more cheatsheets amongst other things. This website is no longer be updated and will eventually be removed when the domain expires.
</p>
<h2 id="gradient-h1" style="margin-top: 3rem;">Bash Cheatsheet</h2>
<p class="info info-box shadow-box">
Bash (Bourne Again Shell) is a shell language build on-top of the orignal Bourne Shell which was distributed with V7 Unix in 1979 and became the standard for writing shell
scripts. Today it is primary to most Linux distributions, MacOS and it has even recently been enabled to run on Windows through something called WSL (Windows Subsystem for
Linux).
<br><br>
This reference sheet should cover most syntax, tips and other tricks there is to Bash scripting. At this moment however (because the site was only recently released) I haven't
gotten around to any explanations! But hopefully a lot of examples should be available in a few months as I'd have had the time to write explanations and script examples by
then.
</p>
</div>
</div>
<div class="row">
<div class="six columns">
<div class="shadow-box">
<h3 id="file-test-operators">File Test Operators</h3></div>
<p class="info-box info shadow-box">Testing files in scripts is easy and straight forward. This is
where
shell scripting
starts to show its glory! In Bash you can do file testing for permissions, size, date, filetype
or
existence.</p>
<!-- <p class="info-box success shadow-box text-align-center"><code class="code-no-wrap">[[ -<flag> <argument> ]]</code><br/><code class="code-no-wrap">[[ <file1> -<flag> <file2> ]]</code> </p>-->
<table class="two-column-table">
<thead>
<tr>
<th>Flag</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td><code data-target="simpleModal_1" data-toggle="modal">-e</code></td>
<td>File exists</td>
</tr>
<tr>
<td><code>-a</code></td>
<td>File exists (identical to -e but is deprecated and outdated)</td>
</tr>
<tr>
<td><code>-f</code></td>
<td>File is a regular file (not a directory or device file)</td>
</tr>
<tr>
<td><code>-s</code></td>
<td>file is not zero size</td>
</tr>
<tr>
<td><code>-d</code></td>
<td>file is a directory</td>
</tr>
<tr>
<td><code>-b</code></td>
<td>file is a block device</td>
</tr>
<tr>
<td><code>-c</code></td>
<td>file is a character device</td>
</tr>
<tr>
<td><code>-p</code></td>
<td>file is a pipe</td>
</tr>
<tr>
<td><code>-h</code></td>
<td>file is a symbolic link</td>
</tr>
<tr>
<td><code>-L</code></td>
<td>file is a symbolic link</td>
</tr>
<tr>
<td><code>-S</code></td>
<td>file is a socket</td>
</tr>
<tr>
<td><code>-t</code></td>
<td>file (descriptor) is associated with a terminal device; this test option may be used
to
check
whether the
stdin [ -t 0 ] or stdout [ -t 1 ] in a given script is a terminal
</td>
</tr>
<tr>
<td><code>-r</code></td>
<td>file has read permission (for the user running the test)</td>
</tr>
<tr>
<td><code>-w</code></td>
<td>file has write permission (for the user running the test)</td>
</tr>
<tr>
<td><code>-x</code></td>
<td>file has execute permission (for the user running the test)</td>
</tr>
<tr>
<td><code>-g</code></td>
<td>set-group-id (sgid) flag set on file or directory</td>
</tr>
<tr>
<td><code>-u</code></td>
<td>set-user-id (suid) flag set on file.</td>
</tr>
<tr>
<td><code>-k</code></td>
<td>sticky bit set.</td>
</tr>
<tr>
<td><code>-O</code></td>
<td>you are owner of file</td>
</tr>
<tr>
<td><code>-G</code></td>
<td>group-id of file same as yours</td>
</tr>
<tr>
<td><code>-N</code></td>
<td>file modified since it was last read</td>
</tr>
<tr>
<td><code class="code-no-wrap">f1 -nt f2</code></td>
<td>file f1 is newer than f2</td>
</tr>
<tr>
<td><code class="code-no-wrap">f1 -ot f2</code></td>
<td>file f1 is older than f2</td>
</tr>
<tr>
<td><code class="code-no-wrap">f1 -ef f2</code></td>
<td>files f1 and f2 are hard links to the same file</td>
</tr>
<tr>
<td><code>!</code></td>
<td><dfn title="A boolean operator which negates any expression.">Not</dfn> – reverses the
sense of the tests above (returns true if condition absent).
</td>
</tr>
</tbody>
</table>
<div class="shadow-box">
<h3 id="job-identifiers">Job Identifiers</h3></div>
<p class="info-box info shadow-box">Job control allows you to selectively stop (suspend) the
execution of
processes and
continue their execution at a later point in time.</p>
<table class="two-column-table">
<thead>
<tr>
<th>Notation</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>%N</code></td>
<td>Job number [N]</td>
</tr>
<tr>
<td><code>%S</code></td>
<td>Invocation (command-line) of job begins with string S</td>
</tr>
<tr>
<td><code>%?S</code></td>
<td>Invocation (command-line) of job contains within it string S</td>
</tr>
<tr>
<td><code>%%</code></td>
<td>"current" job (last job stopped in foreground or started in background)</td>
</tr>
<tr>
<td><code>%+</code></td>
<td>"current" job (last job stopped in foreground or started in background)</td>
</tr>
<tr>
<td><code>%-</code></td>
<td>Last job</td>
</tr>
<tr>
<td><code>%!</code></td>
<td>Last background process</td>
</tr>
</tbody>
</table>
<h3 class="shadow-box" id="signals">Signals</h3>
<p class="info-box info shadow-box">UNIX System V Signals.</p>
<table class="four-column-table">
<thead>
<tr>
<th>Name</th>
<th>Number</th>
<th>Action</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>SIGHUP </code></td>
<td>1</td>
<td>exit</td>
<td>Hangs up</td>
</tr>
<tr>
<td><code>SIGINT </code></td>
<td>2</td>
<td>exit</td>
<td>Interrupts.</td>
</tr>
<tr>
<td><code>SIGQUIT </code></td>
<td>3</td>
<td>core dump</td>
<td>Quits.</td>
</tr>
<tr>
<td><code>SIGILL </code></td>
<td>4</td>
<td>core dump</td>
<td>Illegal instruction.</td>
</tr>
<tr>
<td><code>SIGTRAP </code></td>
<td>5</td>
<td>core dump</td>
<td>Trace trap.</td>
</tr>
<tr>
<td><code>SIGIOT </code></td>
<td>6</td>
<td>core dump</td>
<td>IOT instruction.</td>
</tr>
<tr>
<td><code>SIGEMT </code></td>
<td>7</td>
<td>core dump</td>
<td>MT instruction.</td>
</tr>
<tr>
<td><code>SIGFPE </code></td>
<td>8</td>
<td>core dump</td>
<td>Floating point exception.</td>
</tr>
<tr>
<td><code>SIGKILL </code></td>
<td>9</td>
<td>exit</td>
<td>Kills (cannot be caught or ignored).</td>
</tr>
<tr>
<td><code>SIGBUS </code></td>
<td>10</td>
<td>core dump</td>
<td>Bus error.</td>
</tr>
<tr>
<td><code>SIGSEGV </code></td>
<td>11</td>
<td>core dump</td>
<td>Segmentation violation.</td>
</tr>
<tr>
<td><code>SIGSYS </code></td>
<td>12</td>
<td>core dump</td>
<td>Bad argument to system call.</td>
</tr>
<tr>
<td><code>SIGPIPE </code></td>
<td>13</td>
<td>exit</td>
<td>Writes on a pipe with no one to read it.</td>
</tr>
<tr>
<td><code>SIGALRM </code></td>
<td>14</td>
<td>exit</td>
<td>Alarm clock.</td>
</tr>
<tr>
<td><code>SIGTERM</code></td>
<td>15</td>
<td>exit</td>
<td>Software termination signal.</td>
</tr>
</tbody>
</table>
</div>
<div class="six columns">
<h3 class="shadow-box" id="integer-comparison-operators">Integer Comparison Operators</h3>
<p class="info-box info shadow-box">How to compare integers or arithmetic expressions in shell
scripts.</p>
<table class="two-column-table">
<thead>
<tr>
<th>Flag</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>-eq</code></td>
<td>is equal to</td>
</tr>
<tr>
<td><code>-ne</code></td>
<td>is not equal to</td>
</tr>
<tr>
<td><code>-gt</code></td>
<td>is greater than</td>
</tr>
<tr>
<td><code>-ge</code></td>
<td>is greater than or equal to</td>
</tr>
<tr>
<td><code>-lt</code></td>
<td>is less than</td>
</tr>
<tr>
<td><code>-le</code></td>
<td>is less than or equal to</td>
</tr>
<tr>
<td><code><</code></td>
<td>is less than – place within double parentheses</td>
</tr>
<tr>
<td><code><=</code></td>
<td>is less than or equal to (same rule as previous row)</td>
</tr>
<tr>
<td><code>></code></td>
<td>is greater than (same rule as previous row)</td>
</tr>
<tr>
<td><code>>=</code></td>
<td>is greater than or equal to (same rule as previous row)</td>
</tr>
</tbody>
</table>
<h3 class="shadow-box" id="string-comparison-operators">String Comparison Operators</h3>
<p class="info-box info shadow-box">String comparison in Bash.</p>
<table class="two-column-table">
<thead>
<tr>
<th>Flag</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td>
<code>=</code>
</td>
<td>is equal to</td>
</tr>
<tr>
<td><code>==</code></td>
<td>same as above</td>
</tr>
<tr>
<td><code>!=</code></td>
<td>is not equal to</td>
</tr>
<tr>
<td><code><</code></td>
<td>is less than ASCII alphabetical order</td>
</tr>
<tr>
<td><code>></code></td>
<td>is greater than ASCII alphabetical order</td>
</tr>
<tr>
<td><code>-z</code></td>
<td>string is null (i.e. zero length)</td>
</tr>
<tr>
<td><code>-n</code></td>
<td>string is not null (i.e. !zero length)</td>
</tr>
</tbody>
</table>
<h3 class="shadow-box" id="compound-operators">Compound Operators</h3>
<p class="info-box info shadow-box">Useful for boolean expressions and is similar to <code>&&</code>
and
<code>||</code>.
The compound operators work with the <code>test</code> command or may occur within single
brackets <code>[ <expr> ].</code></p>
<table class="two-column-table">
<thead>
<tr>
<th>Flag</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>-a</code></td>
<td>logical and</td>
</tr>
<tr>
<td><code>-o</code></td>
<td>logical or</td>
</tr>
</tbody>
</table>
<div class="shadow-box">
<h3 id="list-constructs">List Constructs</h3>
</div>
<p class="info-box info shadow-box">Provides a means of processing commands consecutively and in
effect is able to replace complex if/then/case structures.</p>
<table class="two-column-table">
<thead>
<tr>
<th>Construct</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>&&</code></td>
<td>and construct</td>
</tr>
<tr>
<td><code>||</code></td>
<td>or construct</td>
</tr>
</tbody>
</table>
<div class="shadow-box">
<h3 id="reserved-exit-codes">Reserved Exit Codes</h3></div>
<p class="info-box info shadow-box">Useful for debugging a script. <dfn
title="See section about Shell Builtins.">Exit</dfn> takes integer args in the range 0-255.
</p>
<table class="two-column-table">
<thead>
<tr>
<th>Exit Code No.</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>1</code></td>
<td>Catchall for general errors</td>
</tr>
<tr>
<td><code>2</code></td>
<td>Misuse of shell builtins</td>
</tr>
<tr>
<td><code>126</code></td>
<td>Command invoked cannot execute</td>
</tr>
<tr>
<td><code>127</code></td>
<td>Command not found</td>
</tr>
<tr>
<td><code>128</code></td>
<td>Invalid argument to exit</td>
</tr>
<tr>
<td><code>128+n</code></td>
<td>Fatal error signal "n"</td>
</tr>
<tr>
<td><code>130</code></td>
<td>Script terminated by Control-C</td>
</tr>
</tbody>
</table>
<div class="shadow-box">
<h3 id="sending-control-signals">Sending Control Signals</h3></div>
<p class="info-box info shadow-box">You can use these key-combinations to send <dfn
title="A signal is a software interrupt which indicates that an important event has occurred.">signals</dfn>
</p>
<table class="two-column-table">
<thead>
<tr>
<th>Key Combo</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>Ctrl+C</code></td>
<td>The interrupt signal, sends SIGINT to the job running in the foreground.</td>
</tr>
<tr>
<td><code>Ctrl+Y</code></td>
<td>The delayed suspend character. Causes a running process to be stopped when it attempts
to read input from the terminal. Control is returned to the shell, the user can
foreground, background or kill the process. Delayed suspend is only available on
operating systems supporting this feature.
</td>
</tr>
<tr>
<td><code>Ctrl+Z</code></td>
<td>The suspend signal, sends a SIGTSTP to a running program, thus stopping it and returning
control to the shell.
</td>
</tr>
</tbody>
</table>
<p class="info-box warning shadow-box">
Check your <dfn
title="Short for set teletype. It is the command to set up a terminal. stty without options lists the current settings.">stty</dfn>
settings. Suspend and resume of output is usually disabled if you are using
"modern" terminal emulations. The standard <dfn
title="The standard terminal emulator for the X Window System, X11.">xterm</dfn> supports
Ctrl+S and Ctrl+Q by default.</p>
</div>
<div class="eight columns offset-by-two">
</div>
</div>
<div class="row">
<div class="six columns">
<div class="shadow-box">
<h3 id="file-types">File Types</h3></div>
<p class="info-box info shadow-box">This is very different from Windows but straight forward once
you
get it. I'll expand this section soon with more context.</p>
<table class="two-column-table">
<thead>
<tr>
<th>Symbol</th>
<th>Meaning</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>-</code></td>
<td>Regular file</td>
</tr>
<tr>
<td><code>d</code></td>
<td>Directory</td>
</tr>
<tr>
<td><code>l</code></td>
<td>(Symbolic) Link</td>
</tr>
<tr>
<td><code>c</code></td>
<td>Character device</td>
</tr>
<tr>
<td><code>s</code></td>
<td>Socket</td>
</tr>
<tr>
<td><code>p</code></td>
<td>Named pipe</td>
</tr>
<tr>
<td><code>b</code></td>
<td>Block device</td>
</tr>
</tbody>
</table>
<div class="shadow-box">
<h3 id="special-files">Special Files</h3></div>
<p class="info-box info shadow-box">Files that are read by the shell. Listed in order of their execution.</p>
<table class="two-column-table">
<thead>
<tr>
<th>File</th>
<th>Info</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>/etc/profile</code></td>
<td>Executed automatically at login</td>
</tr>
<tr>
<td><code>~.bash_profile</code></td>
<td rowspan="3">Whichever is found first is executed at login.</td>
</tr>
<tr>
<td><code>~/.bash_login</code></td>
</tr>
<tr>
<td><code>~.profile</code></td>
</tr>
<tr>
<td><code>~/.bashrc</code></td>
<td>Is read by every nonlogin shell.</td>
</tr>
</tbody>
</table>
</div>
<div class="six columns">
<div class="shadow-box">
<h3 id="permissions">Permissions</h3>
</div>
<p class="info-box info shadow-box">Now you may know what that arcane looking string
<code>rwxrwxrwx</code>
is when
you invoke <code class="code-no-wrap">ls -l</code></p>
<table class="two-column-table">
<thead>
<tr>
<th>Code</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>s</code></td>
<td>setuid when in <dfn
title="uuugggooo - user column (owners column) is the three first letters in this example.">user
column</dfn></td>
</tr>
<tr>
<td><code>s</code></td>
<td>setgid when in <dfn
title="uuugggooo - group column is the three middle letters in this example.">group
column</dfn></td>
</tr>
<tr>
<td><code>t</code></td>
<td>sticky bit</td>
</tr>
<tr>
<td><code>0</code></td>
<td rowspan="2">The <dfn
title="An access right may be any of the codes you see in this table">access
right</dfn>
that is supposed to be on this place is not granted.
</td>
</tr>
<tr>
<td><code>-</code></td>
</tr>
<tr>
<td><code>4</code></td>
<td rowspan="2"><dfn title="User which is affected by the category may read the file.">read
access</dfn> is granted to the user category defined in this place
</td>
</tr>
<tr>
<td><code>r</code></td>
</tr>
<tr>
<td><code>2</code></td>
<td rowspan="2"><dfn
title="User which is affected by the category may write the file. But the file is not editable in a text editor if you don't have read access.">write
permission</dfn> is granted to the user category defined in this place
</td>
</tr>
<tr>
<td><code>w</code></td>
</tr>
<tr>
<td><code>1</code></td>
<td rowspan="2">execute permission is granted to the user category defined in this place
</td>
</tr>
<tr>
<td><code>x</code></td>
</tr>
<tr>
<td><code>u</code></td>
<td>user permissions</td>
</tr>
<tr>
<td><code>g</code></td>
<td>group permissions</td>
</tr>
<tr>
<td><code>o</code></td>
<td>others permissions</td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="row">
<div class="twelve columns">
<div class="shadow-box">
<h3 id="string-manipulation">String Manipulation</h3></div>
<p class="info-box info shadow-box">Bash supports a surprisingly big number of string operations!
Unfortunately, these tools lack a unified focus. Some are a subset of parameter substitution,
and others fall under the functionality of the UNIX expr command. This results in inconsistent
command syntax and overlap of functionality.</p>
<p class="info-box warning shadow-box">MacOS built-in bash is from 2007 and won't support many of
these.</p>
<table class="two-column-table code-no-wrap" style="overflow-x: scroll; max-width: 100vw;">
<thead>
<tr>
<th>Pattern</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>${#var}</code></td>
<td>Find the length of the string</td>
</tr>
<tr>
<td><code>${var%pattern}</code></td>
<td>Remove from shortest rear (end) pattern</td>
</tr>
<tr>
<td><code>${var%%pattern}</code></td>
<td>Remove from longest rear (end) pattern</td>
</tr>
<tr>
<td><code>${var:position}</code></td>
<td>Extract substring from $var at $position</td>
</tr>
<tr>
<td><code>${var:num1:num2}</code></td>
<td>Substring</td>
</tr>
<tr>
<td><code>${var#pattern}</code></td>
<td>Remove from shortest front pattern</td>
</tr>
<tr>
<td><code>${var##pattern}</code></td>
<td>Remove from longest front pattern</td>
</tr>
<tr>
<td><code>${var/pattern/string}</code></td>
<td>Find and replace (only replace first occurrence)</td>
</tr>
<tr>
<td><code>${var//pattern/string}</code></td>
<td>Find and replace all occurrences</td>
</tr>
<tr>
<td><code>${!prefix*}</code></td>
<td>Expands to the names of variables whose names begin with prefix.
</td>
</tr>
<tr>
<td><code>${var,}</code><br/><code>${var,pattern}</code></td>
<td>Convert first character to lowercase.</td>
</tr>
<tr>
<td><code>${var,,}</code><br/><code>${var,,pattern}</code></td>
<td>Convert all characters to lowercase.</td>
</tr>
<tr>
<td><code>${var^}</code><br/><code>${var^pattern}</code></td>
<td>Convert first character to uppercase.</td>
</tr>
<tr>
<td><code>${var^^}</code><br/><code>${var^^pattern}</code></td>
<td>Convert all character to uppercase.</td>
</tr>
<tr>
<td><code class="code-no-wrap">${string/substring/replacement}</code></td>
<td>Replace first match of $substring with $replacement</td>
</tr>
<tr>
<td><code class="code-no-wrap">${string//substring/replacement}</code></td>
<td>Replace all matches of $substring with $replacement</td>
</tr>
<tr>
<td><code class="code-no-wrap">${string/#substring/replacement}</code></td>
<td>If $substring matches front end of $string, substitute $replacement for $substring</td>
</tr>
<tr>
<td><code class="code-no-wrap">${string/%substring/replacement}</code></td>
<td>If $substring matches back end of $string, substitute $replacement for $substring</td>
</tr>
<tr>
<td><code class="code-no-wrap">expr match "$string" '$substring'</code></td>
<td>Length of matching $substring* at beginning of $string</td>
</tr>
<tr>
<td><code class="code-no-wrap">expr "$string" : '$substring'</code></td>
<td>Length of matching $substring* at beginning of $string</td>
</tr>
<tr>
<td><code class="code-no-wrap">expr index "$string" $substring</code></td>
<td>Numerical position in $string of first character in $substring* that matches [0 if no
match, first character counts as position 1]
</td>
</tr>
<tr>
<td><code class="code-no-wrap">expr substr $string $position $length</code></td>
<td>Extract $length characters from $string starting at $position [0 if no match, first
character counts as position 1]
</td>
</tr>
<tr>
<td><code class="code-no-wrap">expr match "$string" '\($substring\)'</code></td>
<td>Extract $substring*, searching from beginning of $string</td>
</tr>
<tr>
<td><code class="code-no-wrap">expr "$string" : '\($substring\)'</code></td>
<td>Extract $substring* , searching from beginning of $string</td>
</tr>
<tr>
<td><code class="code-no-wrap">expr match "$string" '.*\($substring\)'</code></td>
<td>Extract $substring*, searching from end of $string</td>
</tr>
<tr>
<td><code class="code-no-wrap">expr "$string" : '.*\($substring\)'</code></td>
<td>Extract $substring*, searching from end of $string</td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="row">
<div class="six columns">
<div class="shadow-box">
<h3 id="quoting">Quoting</h3></div>
<p class="info-box info shadow-box">The following text shows characters or that need to be quoted if you want to use their literal symbols and not their special meaning.</p>
<table class="two-column-table">
<thead>
<tr>
<th>Symbol</th>
<th>Literal Meaning</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>;</code></td>
<td>Command seperator</td>
</tr>
<tr>
<td><code>&</code></td>
<td>Background execution</td>
</tr>
<tr>
<td><code>()</code></td>
<td>Command grouping</td>
</tr>
<tr>
<td><code>|</code></td>
<td>Pipe</td>
</tr>
<tr>
<td><code>< > &</code></td>
<td>Redirection symbols</td>
</tr>
<tr>
<td><code>* ? [ ] ~ + - @ !</code></td>
<td>Filename metacharacters</td>
</tr>
<tr>
<td><code>" ' \</code></td>
<td>Used in quoting characters</td>
</tr>
<tr>
<td><code>$</code></td>