libmicrohttpd/doc/examples.html

<center><H3><font color='007700'>libwebserver examples</font></H3></center><BR><BR>

<!-- Johannes E. Schindelin -->
<center><A name=helloworld><B><font color='000077'><a href=/hello><H3>Hello World</H3></a></font></B></center>
<small> <B>used functions:</B><BR>
<a href='/?help=functions#web_server_init'>web_server_init</a><BR>
<a href='/?help=functions#web_server_addhandler'>web_server_addhandler</a><BR>
<a href='/?help=functions#web_server_run'>web_server_run</a><BR>
</small><BR>

This example starts the server with one handler for all requests pointing to hello_world()
that prints the content-type with the end of the header "\r\n\r\n" and one simple printf with Hello world<BR><BR>

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<CODE><PRE>
#include "web_server.h"
#include &lt;stdio.h&gt;


void hello_world() {
	printf("Content-type: text/plain\r\n\r\n");
	printf("Hello, World!\r\n");
}

int main(int argc,char** argv) {
        struct web_server server; // server handler
        if(!web_server_init(&server,80,"help.log",0)) { // initialize and start the server at port 80, logging to help.log
                fprintf(stderr,"can't open listen socket\n");
		return 1;
        };

        web_server_addhandler(&server,"* *",hello_world,0); // add handler for all requests
        while(1) {
                web_server_run(&server);   // run server
        };
}
</PRE></CODE>
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<HR><BR>

<center><A name=logfile><B><font color='000077'><a href='/log'><H3>logfile</H3></a></font></B></center>
<small> <B>used functions:</B><BR>
<a href='/?help=functions#web_server_init'>web_server_init</a><BR>
<a href='/?help=functions#web_server_addhandler'>web_server_addhandler</a><BR>
<a href='/?help=functions#web_server_run'>web_server_run</a><BR>
<a href='/?help=functions#web_client_addfile'>web_client_addfile</a><BR>
</small><BR>

This example uses the function <a href='/?help=functions#web_client_addfile'>web_client_addfile</a> to send a file to client
<BR><BR>
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<CODE><PRE>
#include "web_server.h"
#include &lt;stdio.h&gt;

void logfile() {
        printf("Content-type: text/plain\r\n\r\n");
        web_client_addfile(server.logfile); // add help.log file to output
        printf("End of log\n");
};
        

main() {
        struct web_server server; // server handler
        if(!web_server_init(&server,82,"help.log",0)) { // initializate
                fprintf(stderr,"can't open listen socket\n");
        };

        web_server_addhandler(&server,"* /log",logfile,0); // add handler for http://host/log requests
        while(1) {
                web_server_run(&server);   // run server
        };
};
</PRE></CODE>
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<HR><BR>


<center><A name=imageup><B><font color='000077'><a href='/image'><H3>Image Uploader</H3></a></font></B></center>
<small> <B>used functions:</B><BR>
<a href='/?help=functions#web_server_init'>web_server_init</a><BR>
<a href='/?help=functions#web_server_addhandler'>web_server_addhandler</a><BR>
<a href='/?help=functions#web_server_run'>web_server_run</a><BR>
<a href='/?help=functions#clientinfo'>ClientInfo</a><BR>
</small><BR>


This example uses the struct <a href='/?help=functions#clientinfo'>ClientInfo</a> for fetching the input from the client
using the Query("img") to send the image <BR>
and multipart for fetching the uploaded file<BR>


<BR><BR>
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<CODE><PRE>
#include "web_server.h"
                
#include &lt;stdlib.h&gt;
        
struct image {
	char *data;
	size_t size;
} image={NULL,0};

void imageout() {
	if(strlen(ClientInfo->Query("img"))) {
		if(image.data!=NULL) {
			printf("Content-type: image/jpeg\r\n\r\n");
			fwrite(image.data,image.size,1,stdout);
		};
		return;
	};
	printf("Content-type: text/html\r\n\r\n");
	printf("&lt;HTML&gt;\n");
	printf("&lt;BODY bgcolor='EFEFEF'&gt;\n");        
	printf("&lt;form action='/' enctype='multipart/form-data'&gt;\n");
	printf("&lt;input type=file name=image&gt;&lt;BR&gt;\n");
	printf("&lt;/form&gt;\n");
	if(strlen(ClientInfo->MultiPart("image").data)) {
		printf("%s&lt;BR&gt;&lt;img src='/?img=%s.jpg'&gt;\n",ClientInfo->MultiPart("image").filename,ClientInfo->MultiPart("image").filename);
		free(image.data);
		image.data=malloc(ClientInfo->MultiPart("image").size+1);
		memcpy(image.data,ClientInfo->MultiPart("image").data,ClientInfo->MultiPart("image").size);
		image.size=ClientInfo->MultiPart("image").size;
	}else {
		free(image.data);
		image.data=NULL;
	};
	printf("&lt;/BODY&gt;\n");
	printf("&lt;/HTML&gt;\n");
};



main() {
	struct web_server server;
	if(!web_server_init(&server,80,"teste.log",0)) {
		fprintf(stderr,"can't open listen socket\n");
	};
	web_server_addhandler(&server,"* /",imageout,0);
	while(1) {
		web_server_run(&server);
	};
};
</PRE></CODE>
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<HR><BR>


<center><A name=auth><B><font color='000077'><a href='/auth'><H3>Authentication</H3></a> </font></B></center>
<small> <B>used functions:</B><BR>
<a href='/?help=functions#web_server_init'>web_server_init</a><BR>
<a href='/?help=functions#web_server_addhandler'>web_server_addhandler</a><BR>
<a href='/?help=functions#web_server_run'>web_server_run</a><BR>
<a href='/?help=functions#web_client_HTTPdirective'>web_client_HTTPdirective</a><BR>
</small><BR>

Here we're using the <a href='/?help=functions#web_client_HTTPdirective'>web_client_HTTPdirective</a> to set up the server response

<BR><BR>
user: "username", pass: "password"
<BR>
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<CODE><PRE>
#include "web_server.h"
#include &lt;stdio.h&gt;
#include &lt;string.h&gt;


void urlauthenticate() {
        if(!strlen(ClientInfo->user) || !strlen(ClientInfo->pass) &&
            strcmp(ClientInfo->user,"username") || strcmp(ClientInfo->pass,"password")) { // you can read things from a auth file
                web_client_HTTPdirective("HTTP/1.1 401 Authorization Required");
                printf("WWW-Authenticate: Basic realm=\"This site info\"\r\n");
                printf("Content-type: text/html\r\n\r\n");
                printf("&lt;BODY&gt;\n");
                printf("&lt;font color='FF0000'&gt;Access denied&lt;/font&gt;\n");
                printf("&lt;/BODY&gt;\n");
                return;
        }
        printf("Content-type: text/html\r\n\r\n");         
        printf("&lt;BODY bgcolor='EFEFEF'&gt;\n");        
        printf("You entered in your area\n");
        printf("&lt;/BODY&gt;&lt;/HTML&gt;\n");
};


main() {
        struct web_server server; // server handler
        if(!web_server_init(&server,83,"help.log",0)) { // initialize
                fprintf(stderr,"can't open listen socket\n");
        };

        web_server_addhandler(&server,"* /auth",urlauthenticate,0);
        while(1) {
                web_server_run(&server);   // run server
        };
};
</PRE></CODE>
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<HR><BR>


<CENTER><A name=ssl><B><font color='000077'><H3>openssl for (https)</H3></font></B></CENTER>
<small> <B>used functions:</B><BR>
<a href='/?help=functions#web_server_HTTPdirective'>web_server_useSSLcert</a><BR>
<a href='/?help=functions#web_server_init'>web_server_init</a><BR>
<a href='/?help=functions#web_server_run'>web_server_run</a><BR>
</small><BR>

Here we setup a server and we use the <a href='/?help=functions#web_server_useSSLcert'>web_server_useSSLcert</a> to use specific certificate file
and we start the server with the flag WS_USESSL for secure connections (libwebserver compiled w/ openssl)<BR><BR>

See also the packetmounter example in the example directory. 
<BR>
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<CODE><PRE>

  
#include "web_server.h"

int main()
        struct web_server serverssl;
        web_server_useSSLcert(&serverssl,"foo-cert.pem"); // Certificate file    
        if(!web_server_init(&serverssl,443,"help.log",WS_USESSL)) {
                fprintf(stderr,"Cannot open port\n");
        };
        while(1) {
                web_server_run(&serverssl);
        };
};
</PRE></CODE>
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All the rest is the same as without SSL. 
<HR><BR>


<center><A name=outgif><B><font color='000077'><a href='/gif'><H3>Gif generator</H3></a></font></B></center>
<small> <B>used functions;</B><BR>
<a href='/?help=functions#web_server_init'>web_server_init</a><BR>
<a href='/?help=functions#web_server_addhandler'>web_server_addhandler</a><BR>
<a href='/?help=functions#web_server_run'>web_server_run</a><BR>
<a href='/?help=functions#web_client_gifsetpalette'>web_client_gifsetpalette</a><BR>
<a href='/?help=functions#web_client_gifoutput'>web_client_gifoutput</a><BR>
<a href='/?help=functions#clientinfo'>ClientInfo</a><BR>
</small><BR>

This example draws an circle at x,y requested by client, and outputs with function <a href='/?help=functions#web_client_gifoutput'>web_client_gifoutput</a>


<BR><BR>
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<CODE><PRE>
#include "web_server.h"
#include &lt;stdio.h&gt;
#include &lt;math.h&gt;


#define GIFSIDE 320
char gifdata[GIFSIDE*GIFSIDE];
void outgif() {
	float i;
	int x,y,xc,yc;
	int color;
	web_client_gifsetpalette("EGA");
	if(*ClientInfo->Query("img")!=0) {
		printf("Content-type: image/gif\r\n\r\n");
		if(!strcmp(ClientInfo->Query("img"),"circle")) {
			xc=atoi(ClientInfo->Query("x"))%GIFSIDE;
			yc=atoi(ClientInfo->Query("y"))%GIFSIDE;
			color=(rand()%15)+1;
			for(i=0;i<6.28;i+=0.01) {
				x=(int)(GIFSIDE+(xc+cos(i)*10))%GIFSIDE;
				y=(int)(GIFSIDE+(yc+sin(i)*10))%GIFSIDE;
				gifdata[x+(y*GIFSIDE)]=color;
			};
		};
		web_client_gifoutput(gifdata,GIFSIDE,GIFSIDE);
	};
	printf("&lt;center&gt;Generated a circle (click inside the image)&lt;BR&gt;\n");
	printf("Pressed x=%s,y=%s&lt;BR&gt;\n",ClientInfo->Query("x"),ClientInfo->Query("y"));
	printf("&lt;form&gt;&lt;input type=image border=0 src='/gif?img=circle&x=%s&y=%s'&gt;&lt;/form&gt;&lt;/CENTER&gt;\n",ClientInfo->Query("x"),ClientInfo->Query("y"));
};


main() {
	struct web_server server; // server handler
	memset(gifdata,0,GIFSIDE*GIFSIDE);
	if(!web_server_init(&server,83,"help.log",0)) { // initialize
		fprintf(stderr,"can't open listen socket\n");
	};

	web_server_addhandler(&server,"* /gif",outgif,0);
	while(1) {
		web_server_run(&server);   // run server
	};
};
</PRE></CODE>
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<HR><BR>



<CENTER><A name=cookie><B><font color='000077'><a href=/cookie><H3>Cookies</H3></a></font></B></CENTER>
<small> <B>used functions;</B><BR>
<a href='/?help=functions#web_server_init'>web_server_init</a><BR>
<a href='/?help=functions#web_server_addhandler'>web_server_addhandler</a><BR>
<a href='/?help=functions#web_server_run'>web_server_run</a><BR>
<a href='/?help=functions#clientinfo'>ClientInfo</a><BR>
<a href='/?help=functions#web_client_setcookie'>web_client_setcookie</a><BR>
</small><BR>

This example fetchs an client input and set's an cookie for 15 minutes "+15M" using function <a href='/?help=functions#web_client_setcookie'>web_client_setcookie</a>

<BR><BR>
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<CODE><PRE>
#include "web_server.h"
#include &lt;stdio.h&gt;


void cookie() {
	if(strlen(ClientInfo->Post("user")))
		web_client_setcookie("username",ClientInfo->Post("user"),"+15M");
	printf("Content-type: text/html\r\n\r\n");
	printf("&lt;form method='POST'&gt;\r\n");
	printf("&lt;input type='text' name='user' value='%s'&gt;\r\n&lt;BR&gt;",ClientInfo->Cookie("username"));
	printf("&lt;input type='submit' name='send' value=' GO! '&gt;\r\n&lt;BR&gt;");
	printf("&lt;/form&gt;\r\n");
}

int main(int argc,char** argv) {
        struct web_server server; // server handler
        if(!web_server_init(&server,80,"help.log",0)) { // initialize
                fprintf(stderr,"can't open listen socket\n");
		return 1;
        };

        web_server_addhandler(&server,"* /*",cookie,0); // add handler for all requests
        while(1) {
                web_server_run(&server);   // run server
        };
}

</PRE></CODE>
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<HR><BR>

<center><A name=checkbox><B><font color='000077'><a href=/checkbox><H3>Checkbox</H3></a></font></B></center>
<small> <B>used functions;</B><BR>
<a href='/?help=functions#web_server_init'>web_server_init</a><BR>
<a href='/?help=functions#web_server_addhandler'>web_server_addhandler</a><BR>
<a href='/?help=functions#web_server_run'>web_server_run</a><BR>
<a href='/?help=functions#clientinfo'>ClientInfo</a><BR>
</small><BR>

This example uses a especific case from <a href='/?help=functions#clientinfo'>ClientInfo</a> query and post, using the '#' as prefix of varname returning the number of occurences


<BR><BR>
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<CODE><PRE>

#include "web_server.h"
#include &lt;stdio.h&gt;


void checkbox() {
	int i=0;
	char *txt[]={"one","two","three","four","five"};
	printf("Content-type: text/html\r\n\r\n");
	printf("&lt;form method='QUERY'&gt;\r\n");
	
	for(i=0;i<5;i++) {	
		printf("&lt;input type='checkbox' name='number' value='%s'&gt;\r\n&lt;BR&gt;",txt[i]);	
	};
	printf("&lt;input type='submit' name='send' value=' SEND '&gt;\r\n&lt;BR&gt;");
	printf("&lt;/form&gt;\r\n");
	
	printf("You have choosen &lt;font color='FF0000'&gt;%d&lt;/font&gt; numbers: \r\n",ClientInfo->Query("#number"));
	for(i=0;i&lt;ClientInfo->Query("#number");i++) {	
		printf("&lt;b>%s&lt;/b&gt;,\r\n\r\n",ClientInfo->Query("number"));
	};
	printf("...&lt;BR&gt;\r\n\r\n");
	
}
int main(int argc,char** argv) {
        struct web_server server; // server handler
        if(!web_server_init(&server,80,"help.log",0)) { // initialize
                fprintf(stderr,"can't open listen socket\n");
		return 1;
        };

        web_server_addhandler(&server,"* /*",checkbox,0); // add handler for all requests
        while(1) {
                web_server_run(&server);   // run server
        };
}

</PRE></CODE>
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<HR><BR>

<center><A name=confexample><B><font color='000077'><a href=/confexample><H3>Config example</H3></a></font></B></center>
<small> <B>used functions;</B><BR>
<a href='/?help=functions#web_server_init'>web_server_init</a><BR>
<a href='/?help=functions#web_server_addhandler'>web_server_addhandler</a><BR>
<a href='/?help=functions#web_server_run'>web_server_run</a><BR>
<a href='/?help=functions#web_client_addfile'>web_client_addfile</a><BR>
<a href='/?help=functions#clientinfo'>ClientInfo</a><BR>
</small><BR>


<BR><BR>
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<CODE><PRE>
#include "web_server.h"
#include &lt;stdio.h&gt;


void confexample() {
	printf("Content-type: text/html\r\n\r\n");
	printf("&lt;PRE&gt;");
	web_client_addfile(server.conffile); // add help.cfg file to output	
	printf("&lt;/PRE&gt;");
	printf("ClientInfo->Conf(\"PERSONAL_CONF\",\"PORT\")=%s&lt;BR&gt;\n",ClientInfo->Conf("PERSONAL_CONF","PORT"));
	printf("ClientInfo->Conf(\"PERSONAL_CONF\",\"IP\")=%s&lt;BR&gt;\n",ClientInfo->Conf("PERSONAL_CONF","IP"));
	printf("ClientInfo->Conf(\"LIBWEBSERVER\",\"PORT\")=%s&lt;BR&gt;\n",ClientInfo->Conf("LIBWEBSERVER","PORT"));
	
}

int main(int argc,char** argv) {
        struct web_server server; // server handler
        if(!web_server_init(&server,80,"help.cfg",WS_USEEXTCONF)) { // initialize
                fprintf(stderr,"can't open listen socket\n");
		return 1;
        };

        web_server_addhandler(&server,"* *",confexample,0); // add handler for all requests
        while(1) {
                web_server_run(&server);   // run server
        };
}
</PRE></CODE>
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