ERB(1) Ruby Programmers Reference Guide ERB(1)NAME
erb -- Ruby Templating
SYNOPSIS
erb [--version] [-UPdnvx] [-E ext[:int]] [-S level] [-T mode] [-r library] [--] [file ...]
DESCRIPTION
erb is a command line front-end for ERB library, which is an implementation of eRuby.
ERB provides an easy to use but powerful templating system for Ruby. Using ERB, actual Ruby code can be added to any plain text document for
the purposes of generating document information details and/or flow control.
erb is a part of Ruby.
OPTIONS --version Prints the version of erb.
-E external[:internal]
--encoding external[:internal]
Specifies the default value(s) for external encodings and internal encoding. Values should be separated with colon (:).
You can omit the one for internal encodings, then the value (Encoding.default_internal) will be nil.
-P Evaluates lines starting with % as Ruby code and removes the tailing EOLs.
-S level Specifies the safe level in which eRuby script will run.
-T mode Specifies trim mode (default 0). mode can be one of
0 EOL remains after the embedded ruby script is evaluated.
1 EOL is removed if the line ends with %>.
2 EOL is removed if the line starts with <% and ends with %>.
- EOL is removed if the line ends with -%>. And leading whitespaces are removed if the erb directive starts with
<%-.
-U can be one of Sets the default value for internal encodings (Encoding.default_internal) to UTF-8.
-d
--debug Turns on debug mode. $DEBUG will be set to true.
-h
--help Prints a summary of the options.
-n Used with -x. Prepends the line number to each line in the output.
-v Enables verbose mode. $VERBOSE will be set to true.
-x Converts the eRuby script into Ruby script and prints it without line numbers.
EXAMPLES
Here is an eRuby script
<?xml version="1.0" ?>
<% require 'prime' -%>
<erb-example>
<calc><%= 1+1 %></calc>
<var><%= __FILE__ %></var>
<library><%= Prime.each(10).to_a.join(", ") %></library>
</erb-example>
Command
% erb -T - example.erb
prints
<?xml version="1.0" ?>
<erb-example>
<calc>2</calc>
<var>example.erb</var>
<library>2, 3, 5, 7</library>
</erb-example>
SEE ALSO ruby(1).
And see ri(1) documentation for ERB class.
REPORTING BUGS
Security vulnerabilities should be reported via an email to <security@ruby-lang.org>. Reported problems will be published after being fixed.
And you can report other bugs and feature requests via the Ruby Issue Tracking System (http://bugs.ruby-lang.org). Do not report security
vulnerabilities via the system because it publishes the vulnerabilities immediately.
AUTHORS
Written by Masatoshi SEKI.
UNIX November 7, 2012 UNIX
Check Out this Related Man Page
JRUBY(1) LOCAL JRUBY(1)NAME
jruby -- Interpreted object-oriented scripting language
SYNOPSIS
jruby [--copyright] [--version] [-Sacdlnpswvy] [-0[octal]] [-C directory] [-F pattern] [-I directory] [-K c] [-T[level]] [-e command]
[-i[extension]] [-r library] [-x[directory]] [--] [program_file] [argument ...]
DESCRIPTION
Jruby is a 100% pure-Java implementation of Ruby, an interpreted scripting language for quick and easy object-oriented programming. It has
many features to process text files and to do system management tasks (as in Perl). It is simple, straight-forward, and extensible.
OPTIONS
Ruby interpreter accepts following command-line options (switches). They are quite similar to those of perl(1).
--copyright Prints the copyright notice.
--version Prints the version of Ruby interpreter.
-0[octal] (The digit ``zero''.) Specifies the input record separator ($/) as an octal number. If no digit is given, the null character
is taken as the separator. Other switches may follow the digits. -00 turns Ruby into paragraph mode. -0777 makes Ruby read
whole file at once as a single string since there is no legal character with that value.
-C directory Causes Ruby to switch to the directory.
-F pattern Specifies input field separator ($;).
-I directory Used to tell Ruby where to load the library scripts. Directory path will be added to the load-path variable ($:).
-K kcode Specifies KANJI (Japanese) encoding.
-S Makes Ruby use the PATH environment variable to search for script, unless if its name begins with a slash. This is used to
emulate #! on machines that don't support it, in the following manner:
#! /usr/local/bin/ruby
# This line makes the next one a comment in Ruby
exec /usr/local/bin/ruby -S $0 $*
-T[level] Turns on taint checks at the specified level (default 1).
-a Turns on auto-split mode when used with -n or -p. In auto-split mode, Ruby executes
$F = $_.split
at beginning of each loop.
-c Causes Ruby to check the syntax of the script and exit without executing. If there are no syntax errors, Ruby will print
``Syntax OK'' to the standard output.
-d
--debug Turns on debug mode. $DEBUG will be set to true.
-e command Specifies script from command-line while telling Ruby not to search the rest of arguments for a script file name.
-h
--help Prints a summary of the options.
-i extension Specifies in-place-edit mode. The extension, if specified, is added to old file name to make a backup copy. For example:
% echo matz > /tmp/junk
% cat /tmp/junk
matz
% ruby -p -i.bak -e '$_.upcase!' /tmp/junk
% cat /tmp/junk
MATZ
% cat /tmp/junk.bak
matz
-l (The lowercase letter ``ell''.) Enables automatic line-ending processing, which means to firstly set $ to the value of $/,
and secondly chops every line read using chop!.
-n Causes Ruby to assume the following loop around your script, which makes it iterate over file name arguments somewhat like sed
-n or awk.
while gets
...
end
-p Acts mostly same as -n switch, but print the value of variable $_ at the each end of the loop. For example:
% echo matz | ruby -p -e '$_.tr! "a-z", "A-Z"'
MATZ
-r library Causes Ruby to load the library using require. It is useful when using -n or -p.
-s Enables some switch parsing for switches after script name but before any file name arguments (or before a --). Any switches
found there are removed from ARGV and set the corresponding variable in the script. For example:
#! /usr/local/bin/ruby -s
# prints "true" if invoked with `-xyz' switch.
print "true
" if $xyz
On some systems $0 does not always contain the full pathname, so you need the -S switch to tell Ruby to search for the script
if necessary. To handle embedded spaces or such. A better construct than $* would be ${1+"$@"}, but it does not work if the
script is being interpreted by csh(1).
-v
--verbose Enables verbose mode. Ruby will print its version at the beginning, and set the variable $VERBOSE to true. Some methods
print extra messages if this variable is true. If this switch is given, and no other switches are present, Ruby quits after
printing its version.
-w Enables verbose mode without printing version message at the beginning. It sets the $VERBOSE variable to true.
-x[directory] Tells Ruby that the script is embedded in a message. Leading garbage will be discarded until the first that starts with
``#!'' and contains the string, ``ruby''. Any meaningful switches on that line will applied. The end of script must be spec-
ified with either EOF, ^D (control-D), ^Z (control-Z), or reserved word __END__. If the directory name is specified, Ruby
will switch to that directory before executing script.
-y
--yydebug Turns on compiler debug mode. Ruby will print a bunch of internal state messages during compiling scripts. You don't have to
specify this switch, unless you are going to debug the Ruby interpreter.
UNIX Apr 2, 2007 UNIX