% url.sty  ver 1.1    6-Feb-1996   Donald Arseneau   asnd@triumf.ca

 %

 % A form of \verb that allows linebreaks at certain characters or 

 % combinations of characters, accepts reconfiguration, and can usually

 % be used in the argument to another command.  It is intended for email

 % addresses, hypertext links, directories/paths, etc., which normally 

 % have no spaces.  The font may be selected using the \urlstyle command, 

 % and new url-like commands can be defined using \urldef.

 %

 % Usage:    Conditions:

 % \url{ }   If the argument contains any "%", "#", or "^^", or ends with

 %           "\", it can't be used in the argument to another command.  

 %           The argument must not contain unbalanced braces.

 % \url|  |  ...where "|" is any character not used in the argument and not 

 %           "{".  The same restrictions as above except that the argument

 %           may contain unbalanced braces.

 % \xyz      for "\xyz" a defined-url;  this can be used anywhere, no matter

 %           what characters it contains.

 % 

 % See further instructions after "\endinput"

 \def\url@ttstyle{%

 \@ifundefined{selectfont}{\def\UrlFont{\tt}}{\def\UrlFont{\ttfamily}}% 

 \def\UrlBreaks{\do\.\do\@\do\\\do\/\do\!\do\_\do\|\do\%\do\;\do\>\do\]%

  \do\)\do\,\do\?\do\'\do\+\do\=\do@url@hyp}%

 \def\UrlBigBreaks{\do\:}%

 \def\UrlNoBreaks{\do\(\do\[\do\{\do\<}% (unnecessary)

 \def\UrlSpecials{\do\ {\ }}%

 \def\UrlOrds{\do\*\do\-}% any ordinary characters that aren't usually

 }

 \def\url@rmstyle{%

 \@ifundefined{selectfont}{\def\UrlFont{\rm}}{\def\UrlFont{\rmfamily}}% 

 \def\UrlBreaks{\do\.\do\@\do\/\do\!\do\%\do\;\do\]\do\)\do\,\do\?\do@url@hyp

   \do\+\do\=}%

 \def\UrlBigBreaks{\do\:}%

 \def\UrlNoBreaks{\do\(\do\[\do\{}% prevents breaks after *next* character

 \def\UrlSpecials{\do\<{\langle}\do\>{\rangle\penalty\relpenalty}\do\_{\_%

  \penalty\@m}\do\|{\mid}\do\{{\lbrace}\do\}{\rbrace\penalty\relpenalty}\do

  \\{\mathbin{\backslash}}\do\~{\mathord{{}^{\textstyle\sim}}}\do\ {\ }}%

 \def\UrlOrds{\do\'\do\"\do\-}%

 }

 \def\url@sfstyle{\url@rmstyle 

 \@ifundefined{selectfont}{\def\UrlFont{\sf}}{\def\UrlFont{\sffamily}}% 

 }

 \def\url@samestyle{\ifdim\fontdimen\thr@@\font=\z@ \url@ttstyle \else

   \url@rmstyle \fi \def\UrlFont{}}

 \def\do@url@hyp{}% by default, no breaks after hyphens

 \@ifundefined{strip@prefix}{\def\strip@prefix#1>{}}{}

 \@ifundefined{verbatim@nolig@list}{\def\verbatim@nolig@list{\do\`}}{}

 \def\Url{\relax\ifmmode\@nomatherr$\fi 

  \UrlFont $\fam\z@ \textfont\z@\font 

  \let\do\@makeother \dospecials % verbatim catcodes

  \catcode`{\@ne \catcode`}\tw@ % except braces 

  \medmuskip0mu \thickmuskip\medmuskip \thinmuskip\medmuskip

  \@tempcnta\fam\multiply\@tempcnta\@cclvi 

  \let\do\set@mathcode \UrlOrds % ordinary characters that were special

  \advance\@tempcnta 8192 \UrlBreaks % bin

  \advance\@tempcnta 4096 \UrlBigBreaks % rel

  \advance\@tempcnta 4096 \UrlNoBreaks % open

  \let\do\set@mathact \UrlSpecials % active

  \let\do\set@mathnolig \verbatim@nolig@list % prevent ligatures 

  \@ifnextchar\bgroup\Url@z\Url@y}

 \def\Url@y#1{\catcode`{11 \catcode`}11

   \def\@tempa##1#1{\Url@z{##1}}\@tempa}

 \def\Url@z#1{\def\@tempa{#1}\expandafter\expandafter\expandafter\Url@use

   \expandafter\strip@prefix\meaning\@tempa\, \relax\m@th$\endgroup}

 \let\Url@use\@empty

 \def\set@mathcode#1{\count@`#1\advance\count@\@tempcnta\mathcode`#1\count@}

 \def\set@mathact#1#2{\mathcode`#132768 \lccode`\~`#1\lowercase{\def~{#2}}}

 \def\set@mathnolig#1{\ifnum\mathcode`#1<32768

    \lccode`\~`#1\lowercase{\edef~{\mathchar\number\mathcode`#1_{\/}}}%

    \mathcode`#132768 \fi}

 \def\urldef#1#2{\begingroup \setbox\z@\hbox\bgroup

   \def\Url@z{\Url@def{#1}{#2}}#2}

 \expandafter\ifx\csname DeclareRobustCommand\endcsname\relax

   \def\Url@def#1#2#3{\m@th$\endgroup\egroup\endgroup

     \def#1{#2{#3}}}

 \else

   \def\Url@def#1#2#3{\m@th$\endgroup\egroup\endgroup

     \DeclareRobustCommand{#1}{#2{#3}}}

 \fi

 \def\urlstyle#1{\csname url@#1style\endcsname}

 % Sample (and default) configuration:

 %

 \newcommand\url{\begingroup \Url}

 %

 \newcommand\path{\begingroup \urlstyle{tt}\Url}

 %

 % too many styles define \email like \address, so I will not define it.

 % \newcommand\email{\begingroup \urlstyle{rm}\Url}

 % Process LaTeX \package options

 %

 \urlstyle{tt}

 \@ifundefined{ProvidesPackage}{}{

   \ProvidesPackage{url}[1996/02/06 \space ver 1.1 \space 

        Verb mode for urls, email addresses, and file names]

   \DeclareOption{hyphens}{\def\do@url@hyp{\do\-}}% allow breaks after hyphens

   \DeclareOption{obeyspaces}{\let\Url@use\relax}

   \ProcessOptions

 \ifx\Url@use\relax \def\Url@use#1 #2{#1\ifx\relax#2\@empty\else

   \penalty\relpenalty\ #2\expandafter\Url@use\fi}\fi

 }

 \endinput

 %

 % url.sty  ver 1.1    6-Feb-1996   Donald Arseneau   asnd@reg.triumf.ca

 %

 % This package defines "\url", a form of "\verb" that allows linebreaks,

 % and can often be used in the argument to another command.  It can be

 % configured to print in different formats, and is particularly useful for 

 % hypertext links, email addresses, directories/paths, etc.  The font may 

 % be selected using the "\urlstyle" command and pre-defined text can be 

 % stored with the "\urldef" command. New url-like commands can be defined, 

 % and a "\path" command is provided this way. 

 %

 % Usage:    Conditions:

 % \url{ }   If the argument contains any "%", "#", or "^^", or ends with 

 %           "\", it can't be used in the argument to another command.  

 %           The argument must not contain unbalanced braces.

 % \url|  |  ...where "|" is any character not used in the argument and not 

 %           "{".  The same restrictions as above except that the argument

 %           may contain unbalanced braces.

 % \xyz      for "\xyz" a defined-url;  this can be used anywhere, no matter

 %           what characters it contains.

 % 

 % The "\url" command is fragile, and its argument is likely to be very

 % fragile, but a defined-url is robust.

 %

 % Package Option:  obeyspaces

 % Ordinarily, all spaces are ignored in the url-text.  The "[obeyspaces]" 

 % option allows spaces, but may introduce spurious spaces when a url

 % containing "\" characters is given in the argument to another command.  

 % So if you need to obey spaces should say "\usepackage[obeyspaces]{url}",

 % and if you need both spaces and backslashes, use a `defined-url' for 

 % anything with "\".

 %

 % Package Option:  hyphens

 % Ordinarily, breaks are not allowed after "-" characters because this 

 % leads to confusion. (Is the "-" part of the address or just a hyphen?)  

 % The package option "[hyphens]" allows breaks after explicit hyphen 

 % characters.  The "\url" command will *never ever* hyphenate words.

 % 

 % Defining a defined-url:

 % Take for example the email address "myself%node@gateway.net" which could

 % not be given (using "\url" or "\verb") in a caption or parbox due to the

 % percent sign.  This address can be predefined with 

 %    \urldef{\myself}\url{myself%node@gateway.net}   or

 %    \urldef{\myself}\url|myself%node@gateway.net|

 % and then you may use "\myself" instead of "\url{myself%node@gateway.net}"

 % in an argument, and even in a moving argument like a caption because a

 % defined-url is robust.

 %

 % Style: 

 % You can switch the style of printing using "\urlstyle{tt}", where "tt"

 % can be any defined style.  The pre-defined styles are "tt", "rm", "sf", 

 % and "same" which all allow the same linebreaks but different fonts -- 

 % the first three select a specific font and the "same" style uses the

 % current text font.  You can define your own styles with different fonts 

 % and/or line-breaking by following the explanations below.  The "\url" 

 % command follows whatever the currently-set style dictates.

 %

 % Alternate commands:

 % It may be desireable to have different things treated differently, each

 % in a predefined style; e.g., if you want directory paths to always be 

 % in tt and email addresses to be rm, then you would define new url-like

 % commands as follows:

 %

 %    \newcommand\email{\begingroup \urlstyle{rm}\Url}

 %    \newcommand\directory{\begingroup \urlstyle{tt}\Url}

 %

 % You must follow this format closely, and NOTE that the final command is 

 % "\Url", not "\url".  In fact, the "\directory" example is exactly the 

 % "\path" definition which is pre-defined in the package.  If you look 

 % above, you will see that "\url" is defined with

 %    \newcommand\url{\begingroup \Url}

 % I.e., using whatever url-style has been selected.

 %

 % You can make a defined-url for these other styles, using the usual 

 % "\urldef" command as in this example:

 %

 %    \urldef{\myself}{\email}{myself%node.domain@gateway.net}

 %

 % which makes "\myself" act like "\email{myself%node.domain@gateway.net}",

 % if the "\email" command is defined as above.  The "\myself" command is

 % robust.

 %

 % Defining styles:

 % Before describing how to customize the printing style, it is best to 

 % mention something about the unusual implementation of "\url".  Although

 % the material is textual in nature, and the font specification required

 % is a text-font command, the text is actually typeset in *math* mode.

 % This allows the context-sensitive linebreaking, but also accounts for

 % the default behavior of ignoring spaces.  Now on to defining styles.

 %

 % To change the font or the list of characters that allow linebreaks, you

 % could redefine the commands "\UrlFont", "\UrlBreaks", "\UrlSpecials" etc.

 % directly in the document, but it is better to define a new `url-style' 

 % (following the example of "\url@ttstyle" and "\url@rmstyle") which defines 

 % all of "\UrlBigbreaks", "\UrlNoBreaks", "\UrlBreaks", "\UrlSpecials", and 

 % "\UrlFont".

 %

 % Changing font:

 % The "\UrlFont" command selects the font.  The definition of "\UrlFont"

 % done by the pre-defined styles varies to cope with a variety of LaTeX

 % font selection schemes, but it could be as simple as "\def\UrlFont{\tt}".

 % In addition to setting "\UrlFont", some characters will probably need 

 % to be defined in the "\UrlSpecials" list because most fonts don't have 

 % all the standard input characters.  See the definition of "\url@rmstyle", 

 % which implements "\urlstyle{rm}".  Or even better, follow the definition

 % of "\url@sfstyle", which executes "\url@rmstyle" and then redefines

 % just "\UrlFont".  The nominal format for each special character "c" 

 % in the "\UrlSpecials" list is: "\do\c{<definition>}", but you can 

 % include other definitions too.

 %

 % Changing linebreaks:

 % The list of characters that allow line-breaks is given by "\UrlBreaks" 

 % and "\UrlBigBreaks", which have the format "\do\c" for character "c". 

 % The differences are that `BigBreaks' have a lower penalty and have 

 % different breakpoints when in sequence (as in "http://"): `BigBreaks' 

 % are treated as mathrels while `Breaks' are mathbins (see The TeXbook, 

 % p.170). In particular, a series of `BigBreak' characters will break at 

 % the end and only at the end; a series of `Break' characters will break 

 % after the first and after every following *pair*; there will be no 

 % break after a `Break' character if a `BigBreak' follows.  In the case 

 % of "http://" it doesn't matter whether ":" is a `Break' or `BigBreak' --

 % the breaks are the same in either case; but for DECnet nodes with "::"

 % it is important to prevent breaks *between* the colons, and that is why 

 % colons are `BigBreaks'.

 %

 % It is possible for characters to prevent breaks after the next following 

 % character (I use this for parentheses).  Specify these in "\UrlNoBreaks". 

 %

 % You can do arbitrarily complex things with characters by making them 

 % active in math mode (mathcode hex-8000) and specifying the definition(s)

 % in "\UrlSpecials".  This is used in the rm and sf styles to handle 

 % several characters that are not present in fonts.

 %

 % If all this sounds confusing ... well, it is!  But I hope you won't need 

 % to redefine breakpoints -- the default assignments seem to work well for 

 % a wide variety of applications.  If you do need to make changes, you can 

 % test for breakpoints using regular math mode and the characters "+=(a".

 %

 % Yet more flexibility:

 % You can also set up url.sty to do multiple things with the verbatim text

 % by defining "\Url@use", but the format of the definition is special:

 %

 %    \def\Url@use#1\,{ ... do things with #1 ... }

 %

 % Yes, that is "#1" followed by "\," then the definition.  For example, 

 % to put a hypertext link in the DVI file:

 %

 %    \def\Url@use#1\,{\special{html:<a href="#1">}#1\special{html:</a>}}

 %

 % The End

 % ver 1.1 6-Feb-1996:  

 % Fix hyphens that wouldn't break and ligatures that weren't suppressed.

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 :;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~