1 ==============================================================================

     2 YUI Compressor

     3 ==============================================================================

     4 

     5 NAME

     6 

     7   YUI Compressor - The Yahoo! JavaScript and CSS Compressor

     8 

     9 SYNOPSIS

    10 

    11   Usage: java -jar yuicompressor-x.y.z.jar [options] [input file]

    12 

    13   Global Options

    14     -h, --help                Displays this information

    15     --type <js|css>           Specifies the type of the input file

    16     --charset <charset>       Read the input file using <charset>

    17     --line-break <column>     Insert a line break after the specified column number

    18     -v, --verbose             Display informational messages and warnings

    19     -o <file>                 Place the output into <file>. Defaults to stdout.

    20 

    21   JavaScript Options

    22     --nomunge                 Minify only, do not obfuscate

    23     --preserve-semi           Preserve all semicolons

    24     --disable-optimizations   Disable all micro optimizations

    25 

    26 DESCRIPTION

    27 

    28   The YUI Compressor is a JavaScript compressor which, in addition to removing

    29   comments and white-spaces, obfuscates local variables using the smallest

    30   possible variable name. This obfuscation is safe, even when using constructs

    31   such as 'eval' or 'with' (although the compression is not optimal is those

    32   cases) Compared to jsmin, the average savings is around 20%.

    33 

    34   The YUI Compressor is also able to safely compress CSS files. The decision

    35   on which compressor is being used is made on the file extension (js or css)

    36 

    37 GLOBAL OPTIONS

    38 

    39   -h, --help

    40       Prints help on how to use the YUI Compressor

    41 

    42   --line-break

    43       Some source control tools don't like files containing lines longer than,

    44       say 8000 characters. The linebreak option is used in that case to split

    45       long lines after a specific column. It can also be used to make the code

    46       more readable, easier to debug (especially with the MS Script Debugger)

    47       Specify 0 to get a line break after each semi-colon in JavaScript, and

    48       after each rule in CSS.

    49 

    50   --type js|css

    51       The type of compressor (JavaScript or CSS) is chosen based on the

    52       extension of the input file name (.js or .css) This option is required

    53       if no input file has been specified. Otherwise, this option is only

    54       required if the input file extension is neither 'js' nor 'css'.

    55 

    56   --charset character-set

    57       If a supported character set is specified, the YUI Compressor will use it

    58       to read the input file. Otherwise, it will assume that the platform's

    59       default character set is being used. The output file is encoded using

    60       the same character set.

    61 

    62   -o outfile

    63       Place output in file outfile. If not specified, the YUI Compressor will

    64       default to the standard output, which you can redirect to a file.

    65 

    66   -v, --verbose

    67       Display informational messages and warnings.

    68 

    69 JAVASCRIPT ONLY OPTIONS

    70 

    71   --nomunge

    72       Minify only. Do not obfuscate local symbols.

    73 

    74   --preserve-semi

    75       Preserve unnecessary semicolons (such as right before a '}') This option

    76       is useful when compressed code has to be run through JSLint (which is the

    77       case of YUI for example)

    78 

    79   --disable-optimizations

    80       Disable all the built-in micro optimizations.

    81 

    82 NOTES

    83 

    84   + If no input file is specified, it defaults to stdin.

    85 

    86   + The YUI Compressor requires Java version >= 1.4.

    87 

    88   + It is possible to prevent a local variable, nested function or function

    89     argument from being obfuscated by using "hints". A hint is a string that

    90     is located at the very beginning of a function body like so:

    91 

    92     function fn (arg1, arg2, arg3) {

    93         "arg2:nomunge, localVar:nomunge, nestedFn:nomunge";

    94 

    95         ...

    96         var localVar;

    97         ...

    98 

    99         function nestedFn () {

   100             ....

   101         }

   102 

   103         ...

   104     }

   105 

   106     The hint itself disappears from the compressed file.

   107 

   108   + C-style comments starting with /*! are preserved. This is useful with

   109     comments containing copyright/license information. For example:

   110 

   111     /*!

   112      * TERMS OF USE - EASING EQUATIONS

   113      * Open source under the BSD License.

   114      * Copyright 2001 Robert Penner All rights reserved.

   115      */

   116 

   117     becomes:

   118 

   119     /*

   120      * TERMS OF USE - EASING EQUATIONS

   121      * Open source under the BSD License.

   122      * Copyright 2001 Robert Penner All rights reserved.

   123      */

   124 

   125 AUTHOR

   126 

   127   The YUI Compressor was written and is maintained by:

   128       Julien Lecomte <jlecomte@yahoo-inc.com>

   129   The CSS portion is a port of Isaac Schlueter's cssmin utility.

   130 

   131 COPYRIGHT

   132 

   133   Copyright (c) 2007-2009, Yahoo! Inc. All rights reserved.

   134 

   135 LICENSE

   136 

   137   All code specific to YUI Compressor is issued under a BSD license.

   138   YUI Compressor extends and implements code from Mozilla's Rhino project.

   139   Rhino is issued under the Mozilla Public License (MPL), and MPL applies

   140   to the Rhino source and binaries that are distributed with YUI Compressor.