[catagits/fcgi2.git] / doc / fastcgi-prog-guide / ch4tcl.htm

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
   <HEAD>
      <TITLE>
         FastCGI Programmer&#39;s Guide - Chapter 4, Developing FastCGI Applications in Tcl
      </TITLE>
<STYLE TYPE="text/css">
 body {
  background-color: #ffffff;
 }
 li.c2 {list-style: none}
 div.c1 {text-align: center}
</STYLE>
   </HEAD>
   <BODY>
      <A HREF="cover.htm">[Top]</A> <A HREF="ch3perl.htm">[Prev]</A> <A HREF="apaman.htm">[Next]</A> <A HREF=
      "ap_guida.htm">[Bottom]</A> 
      <HR>
      <BR>
       <A NAME="3659"></A>
      <DIV CLASS="c1">
         <H1>
            4 Developing FastCGI<BR>
            Applications in Tcl
         </H1>
      </DIV>
      <A NAME="4835"></A>
      <P>
         This chapter explains how to code FastCGI applications in Tcl. Prior to creating a FastCGI application, you
         must have a FastCGI-savvy version of the Tcl interpreter. Open Market develops Tcl binaries for popular
         platforms and makes them available with our developer&#39;s kit.
      </P>
      <P>
         <A NAME="4943"></A> The FastCGI-savvy binaries are extensions of standard Tcl, and are intended to replace
         your existing Tcl installation. There is no need to maintain two versions of Tcl: the version that we supply
         will work fine when invoked from a shell or a CGI program. There are also directions in the developer&#39;s
         kit for how to make your own FastCGI-savvy Tcl, if you need a version for some platform that we don&#39;t
         supply.
      </P>
      <P>
         <A NAME="4221"></A> In many cases, you can convert a Tcl script from CGI to FastCGI by adding a few lines of
         code to an existing script. For more complex scripts, you may also need to rearrange some existing code.
      </P>
      <BR>
      <BR>
      <H1>
         Getting Started
      </H1>
      <A NAME="4223"></A>
      <P>
         The first line of any Tcl script typically specifies the pathname of the Tcl interpreter itself. You must
         specify the pathname of a FastCGI-savvy Tcl.
      </P>
      <P>
         <A NAME="4226"></A> Then, you have to divide FastCGI scripts into the following two sections:
      </P>
      <BR>
      <BR>
      <UL>
         <LI CLASS="c2">
            <A NAME="4227"></A>
         </LI>
         <LI>
            Initialization section, which is executed only once. <A NAME="4228"></A>
         </LI>
         <LI>
            Response loop section, which gets executed every time the FastCGI script gets called.
         </LI>
      </UL>
      <A NAME="4229"></A>
      <P>
         A response loop typically has the following format:
      </P>
      <BR>
      <BR>
<PRE>
<A NAME="4923">while {[FCGI_Accept] &gt;= 0 } {
</A>
<A NAME="4925"># body of response loop
</A>
<A NAME="4367">}
</A>
</PRE>
      <A NAME="4233"></A>
      <P>
         The <CODE>FCGI_Accept</CODE> call returns 0 whenever a client requests the FastCGI script. Otherwise, the
         <CODE>FCGI_Accept</CODE> call returns -1.
      </P>
      <BR>
      <BR>
      <H1>
         Example: TinyFastCGI
      </H1>
      <A NAME="4343"></A>
      <P>
         Here is a simple example of a FastCGI application written in Tcl:
      </P>
      <BR>
      <BR>
<PRE>
<A NAME="4344"></A>
#!fcgi-savvy-tcl

set count 0

# Response Loop
while {[FCGI_Accept] &gt;= 0 } {
        incr count
        puts -nonewline &quot;Content-type: text/html\r\n\r\n&quot;
        puts &quot;&lt;title&gt;FastCGI Hello! (Tcl)&lt;/title&gt;&quot;
        puts &quot;&lt;h1&gt;FastCGI Hello! (Tcl)&lt;/h1&gt;&quot;
        puts &quot;Request number $count running on host  &lt;i&gt;$env(SERVER_NAME)&lt;/i&gt;&quot;
}
</PRE>
      <P>
      </P>
      <HR>
      <BR>
       <A HREF="cover.htm">[Top]</A> <A HREF="ch3perl.htm">[Prev]</A> <A HREF="apaman.htm">[Next]</A> <A HREF=
      "ap_guida.htm">[Bottom]</A> 
      <HR>
      <BR>
       <!-- This file was created with Quadralay WebWorks Publisher 3.0.3 -->
      <!-- -->
      <!-- For more information on how this document, and how the rest of -->
      <!-- this server was created, email yourEmail@xyzcorp.com -->
      <!-- -->
      <!-- Last updated: 04/15/96 08:00:19 -->
   </BODY>
</HTML>
Commit	Line	Data
852467e2	1	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN">
	2	<HTML>
	3	<HEAD>
	4	<TITLE>
	5	FastCGI Programmer's Guide - Chapter 4, Developing FastCGI Applications in Tcl
	6	</TITLE>
	7	<STYLE TYPE="text/css">
	8	body {
	9	background-color: #ffffff;
	10	}
	11	li.c2 {list-style: none}
	12	div.c1 {text-align: center}
	13	</STYLE>
	14	</HEAD>
	15	<BODY>
	16	<A HREF="cover.htm">[Top]</A> <A HREF="ch3perl.htm">[Prev]</A> <A HREF="apaman.htm">[Next]</A> <A HREF=
	17	"ap_guida.htm">[Bottom]</A>
	18	<HR>
	19	<BR>
	20	<A NAME="3659"></A>
	21	<DIV CLASS="c1">
	22	<H1>
	23	4 Developing FastCGI<BR>
	24	Applications in Tcl
	25	</H1>
	26	</DIV>
	27	<A NAME="4835"></A>
	28	<P>
	29	This chapter explains how to code FastCGI applications in Tcl. Prior to creating a FastCGI application, you
	30	must have a FastCGI-savvy version of the Tcl interpreter. Open Market develops Tcl binaries for popular
	31	platforms and makes them available with our developer's kit.
	32	</P>
	33	<P>
	34	<A NAME="4943"></A> The FastCGI-savvy binaries are extensions of standard Tcl, and are intended to replace
	35	your existing Tcl installation. There is no need to maintain two versions of Tcl: the version that we supply
	36	will work fine when invoked from a shell or a CGI program. There are also directions in the developer's
	37	kit for how to make your own FastCGI-savvy Tcl, if you need a version for some platform that we don't
	38	supply.
	39	</P>
	40	<P>
	41	<A NAME="4221"></A> In many cases, you can convert a Tcl script from CGI to FastCGI by adding a few lines of
	42	code to an existing script. For more complex scripts, you may also need to rearrange some existing code.
	43	</P>
	44	<BR>
	45	<BR>
	46	<H1>
	47	Getting Started
	48	</H1>
	49	<A NAME="4223"></A>
	50	<P>
	51	The first line of any Tcl script typically specifies the pathname of the Tcl interpreter itself. You must
	52	specify the pathname of a FastCGI-savvy Tcl.
	53	</P>
	54	<P>
	55	<A NAME="4226"></A> Then, you have to divide FastCGI scripts into the following two sections:
	56	</P>
	57	<BR>
	58	<BR>
	59	<UL>
	60	<LI CLASS="c2">
	61	<A NAME="4227"></A>
	62	</LI>
	63	<LI>
	64	Initialization section, which is executed only once. <A NAME="4228"></A>
65	</LI>
66	<LI>
67	Response loop section, which gets executed every time the FastCGI script gets called.
68	</LI>
69	</UL>
70	<A NAME="4229"></A>
71	<P>
72	A response loop typically has the following format:
73	</P>
74	<BR>
75	<BR>
76	<PRE>
77	<A NAME="4923">while {[FCGI_Accept] >= 0 } {
78	</A>
79	<A NAME="4925"># body of response loop
80	</A>
81	<A NAME="4367">}
82	</A>
83	</PRE>
84	<A NAME="4233"></A>
85	<P>
86	The <CODE>FCGI_Accept</CODE> call returns 0 whenever a client requests the FastCGI script. Otherwise, the
87	<CODE>FCGI_Accept</CODE> call returns -1.
88	</P>
89	<BR>
90	<BR>
91	<H1>
92	Example: TinyFastCGI
93	</H1>
94	<A NAME="4343"></A>
95	<P>
96	Here is a simple example of a FastCGI application written in Tcl:
97	</P>
98	<BR>
99	<BR>
100	<PRE>
101	<A NAME="4344"></A>
102	#!fcgi-savvy-tcl
103
104	set count 0
105
106	# Response Loop
107	while {[FCGI_Accept] >= 0 } {
108	incr count
109	puts -nonewline "Content-type: text/html\r\n\r\n"
110	puts "<title>FastCGI Hello! (Tcl)</title>"
111	puts "<h1>FastCGI Hello! (Tcl)</h1>"
112	puts "Request number $count running on host <i>$env(SERVER_NAME)</i>"
113	}
114	</PRE>
115	<P>
116	</P>
117	<HR>
118	<BR>
119	<A HREF="cover.htm">[Top]</A> <A HREF="ch3perl.htm">[Prev]</A> <A HREF="apaman.htm">[Next]</A> <A HREF=
120	"ap_guida.htm">[Bottom]</A>
121	<HR>
122	<BR>
123	<!-- This file was created with Quadralay WebWorks Publisher 3.0.3 -->
124	<!-- -->
125	<!-- For more information on how this document, and how the rest of -->
126	<!-- this server was created, email yourEmail@xyzcorp.com -->
127	<!-- -->
128	<!-- Last updated: 04/15/96 08:00:19 -->
129	</BODY>
130	</HTML>
131