I had the need to pass a program’s [standard] output to a web browser in real time. The best solution for this is to use a combination of programs made in different languages. The following are all of these individual components to accomplish this task.
Please note the C components are only compatible with gcc and bash (cygwin required for Windows), as MSVC and Windows command prompt are missing vital functionality for this to work.
The first component is a server made in C that receives stdin (as a pipe, or typed by the user after line breaks) and sends that data out to a connected client (buffering the output until the client connects).
Define “WINDOWS” when compiling in Windows (pass “-DWINDOWS”)
Source Code:
#include <stdio.h>
#include <malloc.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <signal.h>
//The server socket and options
int ServerSocket=0;
const int PortNumber=1234; //The port number to listen in on
//If an error occurs, exit cleanly
int error(char *msg)
{
//Close the socket if it is still open
if(ServerSocket)
close(ServerSocket);
ServerSocket=0;
//Output the error message, and return the exit status
fprintf(stderr, "%s\n", msg);
return 1;
}
//Termination signals
void TerminationSignal(int sig)
{
error("SIGNAL causing end of process");
_exit(sig);
}
int main(int argc, char *argv[])
{
//Listen for termination signals
signal(SIGINT, TerminationSignal);
signal(SIGTERM, TerminationSignal);
signal(SIGHUP, SIG_IGN); //We want the server to continue running if the environment is closed, so SIGHUP is ignored -- This doesn't work in Windows
//Create the server
struct sockaddr_in ServerAddr={AF_INET, htons(PortNumber), INADDR_ANY, 0}; //Address/port to listen on
if((ServerSocket=socket(AF_INET, SOCK_STREAM, 0))<0) //Attempt to create the socket
return error("ERROR on 'socket' call");
if(bind(ServerSocket, (struct sockaddr*)&ServerAddr, sizeof(ServerAddr))<0) //Bind the socket to the requested address/port
return error("ERROR on 'bind' call");
if(listen(ServerSocket,5)<0) //Attempt to listen on the requested address/port
return error("ERROR on 'listen' call");
//Accept a connection from a client
struct sockaddr_in ClientAddr;
int ClientAddrLen=sizeof(ClientAddr);
int ClientSocket=accept(ServerSocket, (struct sockaddr*)&ClientAddr, &ClientAddrLen);
if(ClientSocket<0)
return error("ERROR on 'accept' call");
//Prepare to receive info from STDIN
//Create the buffer
const int BufferSize=1024*10;
char *Buffer=malloc(BufferSize); //Allocate a 10k buffer
//STDIN only needs to be set to binary mode in windows
const int STDINno=fileno(stdin);
#ifdef WINDOWS
_setmode(STDINno, _O_BINARY);
#endif
//Prepare for blocked listening (select function)
fcntl(STDINno, F_SETFL, fcntl(STDINno, F_GETFL, 0)|O_NONBLOCK); //Set STDIN as blocking
fd_set WaitForSTDIN;
FD_ZERO(&WaitForSTDIN);
FD_SET(STDINno, &WaitForSTDIN);
//Receive information from STDIN, and pass directly to the client
int RetVal=0;
while(1)
{
//Get the next block of data from STDIN
select(STDINno+1, &WaitForSTDIN, NULL, NULL, NULL); //Wait for data
size_t AmountRead=fread(Buffer, 1, BufferSize, stdin); //Read the data
if(feof(stdin) || AmountRead==0) //If input is closed, process is complete
break;
//Send the data to the client
if(write(ClientSocket,Buffer,AmountRead)<0) //If error in network connection occurred
{
RetVal=error("ERROR on 'write' call");
break;
}
}
//Cleanup
if(ServerSocket)
close(ServerSocket);
free(Buffer);
return RetVal;
}
The next component is a Flash applet as the client to receive data. Flash is needed as it can keep a socket open for realtime communication. The applet receives the data and then passes it through to JavaScript for final processing.
import flash.external.ExternalInterface;
import flash.events.Event;
ExternalInterface.addCallback("OpenSocket", OpenSocket);
function OpenSocket(IP:String, Port:Number):void
{
SendInfoToJS("Trying to connect");
var TheSocket:Socket = new Socket();
TheSocket.addEventListener(Event.CONNECT, function(Success) { SendInfoToJS(Success ? "Connected!" : "Could not connect"); });
TheSocket.addEventListener(Event.CLOSE, function() { SendInfoToJS("Connection Closed"); });
TheSocket.addEventListener(IOErrorEvent.IO_ERROR, function() {SendInfoToJS("Could not connect");});
TheSocket.addEventListener(ProgressEvent.SOCKET_DATA, function(event:ProgressEvent):void { ExternalInterface.call("GetPacket", TheSocket.readUTFBytes(TheSocket.bytesAvailable)); });
TheSocket.connect(IP, Port);
}
function SendInfoToJS(str:String) { ExternalInterface.call("GetInfoFromFlash", str); }
stop();
Flash sockets can also be implemented in ActionScript 1.0 Code (I did not include hooking up ActionScript 1.0 with JavaScript in this example. “GetPacket” and “SendInfoToJS” need to be implemented separately. “IP” and “Port” need to also be received separately).
var NewSock=new XMLSocket();
NewSock.onData=function(msg) { GetPacket(msg); }
NewSock.onConnect=function(Success) { SendInfoToJS(Success ? "Connected!" : "Could not connect"); }
SendInfoToJS(NewSock.connect(IP, Port) ? "Trying to Connect" : "Could not start connecting");
JavaScript can then receive (and send) information from (and to) the Flash applet through the following functions.
FLASH.OpenSocket(StringIP, Number Port): Call this from JavaScript to open a connection to a server. Note the IPMIGHT have to be the domain the script is running on for security errors to not be thrown.
JAVASCRIPT.GetInfoFromFlash(String): This is called from Flash whenever connection information is updated. I have it giving arbitrary strings ATM.
JAVASCRIPT.GetPacket(String): This is called from Flash whenever data is received through the connection.
This example allows the user to input the IP to connect to that is streaming the output. Connection information is shown in the “ConnectionInfo” DOM object. Received data packets are appended to the document in separate DOM objects.
var isIE=navigator.appName.indexOf("Microsoft")!=-1;
function getFlashMovie(movieName) { return (isIE ? window[movieName] : document[movieName]); }
function $(s) { return document.getElementById(s); }
function Connect()
{
getFlashMovie("client").OpenSocket($('IP').value, 1234);
}
function GetInfoFromFlash(Str)
{
$('ConnectionInfo').firstChild.data=Str;
}
function GetPacket(Str)
{
var NewDiv=document.createElement('DIV');
NewDiv.appendChild(document.createTextNode(Str));
$('Info').appendChild(NewDiv);
}
Next is an example application that outputs to stdout. It is important that it flushes stdout after every output or the communication may not be real time.
inc counts from 0 to one less than a number (parameter #1 [default=50]) after a certain millisecond interval (parameter #2 [default=500]).
[Bash] Example:
./inc 10 #Counts from 0-9 every half a second
Source Code:
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
int NumLoops=(argc>1 ? atoi(argv[1]) : 50); //Number of loops to run from passed argument 1. Default is 50 if not specified.
int LoopWait=(argc>2 ? atoi(argv[2]) : 500); //Number of milliseconds to wait in between each loop from passed argument 2. Default is 500ms if not specified.
LoopWait*=1000; //Convert to microseconds for usleep
//Output an incremented number every half a second
int i=0;
while(i<NumLoops)
{
printf("%u\n", i++);
fflush(stdout); //Force stdout flush
usleep(LoopWait); //Wait for half a second
};
return 0;
}
This final component is needed so the Flash applet can connect to a server. Unfortunately, new versions of Flash (at least version 10, might have been before that though) started requiring policies for socket connections >:-(. I don’t think this is a problem if you compile your applet to target an older version of Flash with the ActionScript v1.0 code.
This Perl script creates a server on port 843 to respond to Flash policy requests, telling any Flash applet from any domain to allow connections to go through to any port on the computer (IP). It requires Perl, and root privileges on Linux to bind to a port <1024 (su to root or run with sudo).
#!/usr/bin/perl
use warnings;
use strict;
#Listen for kill signals
$SIG{'QUIT'}=$SIG{'INT'}=$SIG{__DIE__} = sub
{
close Server;
print "Socket Policy Server Ended: $_[0]\n";
exit;
};
#Start the server:
use Socket;
use IO::Handle;
my $FlashPolicyPort=843;
socket(Server, PF_INET, SOCK_STREAM, getprotobyname('tcp')) or die "'socket' call: $!"; #Open the socket
setsockopt(Server, SOL_SOCKET, SO_REUSEADDR, 1) or die "'setsockopt' call: $!"; #Allow reusing of port/address if in TIME_WAIT state
bind(Server, sockaddr_in($FlashPolicyPort,INADDR_ANY)) or die "'bind' call: $!"; #Listen on port $FlashPolicyPort for connections from any INET adapter
listen(Server,SOMAXCONN) or die "'listen' call: $!"; #Start listening for connections
Server->autoflush(1); #Do not buffer output
#Infinite loop that accepts connections
$/ = "\0"; #Reset terminator from new line to null char
while(my $paddr=accept(Client,Server))
{
Client->autoflush(1); #Do not buffer IO
if(<Client> =~ /.*policy\-file.*/i) { #If client requests policy file...
print Client '<cross-domain-policy><allow-access-from domain="*" to-ports="*" /></cross-domain-policy>'.$/; #Output policy info: Allow any flash applets from any domain to connect
}
close Client; #Close the client
}
This could very easily be converted to another better [less resource intensive] language too.
How to tie all of this together
Start the servers
In your [bash] command shell, execute the following
Server/FlashSocketPolicy.pl & #Run the Flash Policy Server as a daemon. Don't forget sudo in Linux
./inc | ./PassThruServer #Pipe inc out to the PassThruServer
Note that this will immediately start the PassThruServer receiving information from “inc”, so if you don’t get the client up in time, it may already be done counting and send you all the info at once (25 seconds).
The PassThruServer will not end until one of the following conditions has been met:
The client has connected and the piped process is completed
The client has connected and disconnected and the disconnect has been detected (when a packet send failed)
It is manually killed through a signal
The Flash Policy Server daemon should probably just be left on indefinitely in the background (it only needs to be run once).
To run the client, open client.html through a web server [i.e. Apache’s httpd] in your web browser. Don’t open the local file straight through your file system, it needs to be run through a web server for Flash to work correctly.
Click “connect” (assuming you are running the PassThruServer already on localhost [the same computer]). You can click “connect” again every time a new PassThruServer is ran.
The one time I decide to look online before trying it out myself
A client of mine wanted their website to have an applet that played streaming music from a SHOUTcast server. The easy solution would have been to just embed a Windows Media Player applet into the page, but that would only work for IE.
I thoroughly searched the web and was unable to find a Flash applet (or other solution) that already did this (and actually worked). Most of the information I was finding was people having problems getting this kind of thing working in Flash with no answer provided. After giving up on finding a resolution online, I decided to load up Flash and see what I could find from some tinkering.
Quite frankly, I’m shocked people were having so many problems with this. I started an ActionScript 2.0 project and put in the following code, and it worked right away in Flash CS3 (v9.0) with no problem:
var URL="http://example.shoutcast.castledragmire.com:1234/" //The URL to the SHOUTcast server
var MySound:Sound=new Sound(this);
MySound.loadSound(URL,true);
Unfortunately, once I exported the Flash applet and loaded it up in my browsers, it was no longer working. After a few minutes of poking around, I had a hunch that the SHOUTcast host might be sending different data depending on the [Browser’s] User Agent. I changed Firefox’s User Agent to “Flash” through a Firefox add-on (User Agent Switcher), and it worked :-D.
Once again, unfortunately, this was not a viable solution because I couldn’t have every user who visited the client’s web page change their browser User Agent string :-). The quickest solution at this point to the problem was to just create a passthrough script that grabbed the live stream on their server and passed it to the client. The following is the PHP script I used for this:
Setting the Flash Applet’s URL variable to the PHP file
Turning off PHP output buffering for the file. This can only be done through Apache or the php.ini depending on the server setup. This is very important, as if it’s on, the data will never get sent to the user.
The only problem with this method is that it taxes the server that is passing the data through, especially since it uses PHP... This kind of thing could very easily be done in C though (as a matter of fact, I will be writing a post on something very close to that very soon).
To continue the subject in my last post, these next cross-window bugs also derive from objects not being recognized properly when being passed between windows in JavaScript.
I needed the ability to dynamically run functions in the secondary window form the primary window where the parameters are taken from an array. Since a “function” from a secondary window is not seen as a function object from the primary window in IE, the apply member was not working.
I have included a fix for this below in the “RunFunctionInRemoteWindow” function, which is just a wrapper function in the second window that calls the apply function. This function manually copies the array through a for loop, instead of using slice, because in IE7 (but not IE8), the passed arrays were not seen as valid JSObjects, so the slice method (which is a standard method used for copying arrays by value) was not working.
<html><body>
<input type=button onclick="RunTest();" value='Click me when the second window has opened to run the test'>
<script type="text/javascript">
//Spawn the second window
var NewWindow=window.open('RemoteWindow.html');
//Run the test
function RunTest()
{
LocalAlertString('This is an alert generated from the local window');
NewWindow.RemoteAlertString('This is an alert generated from the remote window');
alert('The local window alert function is of type function: '+(LocalAlertString instanceof Function));
alert('The remote window alert function is of type function: '+(NewWindow.RemoteAlertString instanceof Function));
LocalAlertString.apply(window, ['This is an alert generated from the local window through the APPLY member']);
try {
NewWindow.RemoteAlertString.apply(NewWindow.window, ['This is an alert generated from the remote window through the APPLY member. This will not work in IE because the remote window\'s function is not actually a function.']);
} catch(e) { alert('The REMOTE APPLY failed: '+e.message); }
NewWindow.RunFunctionInRemoteWindow('RemoteAlertString', ['This is an alert generated from the remote window through the FIXED APPLY function.']);
}
//Generate an alert in the local window
function LocalAlertString(TheString)
{
alert('Local String: '+TheString);
}
</script></body></html>
RemoteWindow.html [do not run this one, it is opened as a popup from LocalWindow.html]
<html><body><script type="text/javascript">
//Generate an alert in the remote window
function RemoteAlertString(TheString)
{
alert('Remote String: '+TheString);
}
//Call functions in this window remotely through the "apply" member
function RunFunctionInRemoteWindow(FunctionName, Parameters)
{
//Manually copy the passed Parameters since "Parameters" may not be a valid JSObject anymore (this could be detected and array.slice used if it is still valid)
var ParametersCopy=[];
for(var i=0;i<Parameters.length;i++)
ParametersCopy[i]=Parameters[i];
window[FunctionName].apply(window, ParametersCopy);
}
</script></body></html>
I was doing some research around April of 2009 on JavaScript interaction between web browser windows. I was doing this because web browsers are starting to split off each tab/window into separate processes/threads (Firefox is lagging in this), which can lead to some useful new implementations in the browser world, including multithreading. I wanted to explore the interaction between these windows to make sure there were no caveats that might creep up if I decided to take advantage of this.
The first one I found was that each browser window has its own instance of all of the base object classes, so prototypes do not carry over, and instanceof will not work as expected.
For example, if in WindowOne, you add a prototype to the Array class called IsArray, it is only accessible by arrays created in WindowOne. If you pass an array created in WindowOne into a second window, the prototype is still available on that one array (IIRC this was not true of some of the browsers at the time, but I tested again today, and it worked for IE8, Firefox3, and Google Chrome). Also, since the base object class in Window1 and other windows are not the same, an object created in Window1 and passed to another window will return false in a instanceof Object operation in that other window.
Here is some example code to help show what I’m talking about.
<html><body>
<input type=button onclick="RunTest();" value='Click me when the second window has opened to run the test'>
<script type="text/javascript">
Array.prototype.IsArray=true;
var NewWindow=window.open('RemoteWindow.html'); //Spawn the second window
function RunTest() { NewWindow.RunTest({}, [], new ExampleObject()); }; //Send the test data to remote window
function ExampleObject() { } //An example class
</script></body></html>
RemoteWindow.html [do not run this one, it is opened as a popup from LocalWindow.html]
<html><body><script type="text/javascript">
function RunTest(AnObject, AnArray, AnExampleObject)
{
var MyTests=[
'AnObject instanceof Object',
'AnObject.IsArray', //Object.prototype does not have this (Array.prototype does)
'AnArray instanceof Object',
'AnArray instanceof Array',
'AnArray.IsArray', //This was added to the Array.prototype in the parent window
'AnArray instanceof opener.Array', //This example does not work in IE7 because opener.x cannot be properly accessed
'AnExampleObject instanceof opener.ExampleObject',//This example does not work in IE7 because opener.x cannot be properly accessed
'AnExampleObject instanceof ExampleObject' //This test should error because "ExampleObject" does not exist in this window
];
for(var i=0;i<MyTests.length;i++) //This runs each test like the following: alert("TEST: "+(TEST));
try {
eval('alert("'+MyTests[i]+': "+('+MyTests[i]+'));');
} catch(e) {
alert('Error on test "'+MyTests[i]+'": '+(e.hasOwnProperty('message') ? e.message : e.toString()));
}
}
</script></body></html>
Another useful little Unix like utility for command line
This is a modification of the utility I made in yesterday’s post, chunk, and most of the information mentioned in that post applies to this one too. This utility instead writes bytes from STDIN to a certain byte offset of a preexisting file. Below is the source code for the result, which I call chunkwrite (Windows Executable).
Chunkwrite writes bytes to a file at a given offset from STDIN. The parameters are:
1) The file to write to
2) The byte offset to write at (hex is supported like 0xA)
The source is as follows:
//Copyright 2009 by Dakusan (http://www.castledragmire.com/Copyright). Licensed under Dakusan License v2.0 (http://www.castledragmire.com/Misc/Software_Licenses/Dakusan_License_v2.0.php).
//See http://www.castledragmire.com/Posts/chunkwrite for more information
#define __LARGE64_FILES
#include <stdio.h>
#include <stdlib.h> //strtoull
#ifdef WIN32 //STDIN only needs to be set to binary mode in windows
#include <io.h> //_setmode
#include <fcntl.h> //_O_BINARY
#endif
typedef unsigned long long UINT64;
const UINT64 MaxSizeToRead=1024*1024*10; //The maximum number of bytes to read at a time to our buffer (Must be < 2^31)
UINT64 GetNumberFromString(const char* S) //Extract both hexidecimal and decimal numbers from a string
{
bool IsHex=S[0]=='0' && (S[1]|32=='x'); //If string starts as 0x, then is a hex number
return strtoull(S+(IsHex ? 2 : 0), NULL, IsHex ? 16 : 10); //Hex number starts after 2 characters and uses base 16
}
int main(int argc, char *argv[], char *envp[])
{
//Determine if proper number of parameters are passed, and if not, output help info
if(argc!=3)
return fprintf(stderr, "Chunkwrite writes bytes to a file at a given offset from STDIN. The parameters are:\n1) The file to write to\n2) The byte offset to write at (hex is supported like 0xA)\n") & 0;
//Open the file to output to
FILE *TheFile=fopen64(argv[1], "r+b");
if(TheFile==NULL)
return fprintf(stderr, "File not found or cannot open file\n") & 0;
//Determine the requested start offset
UINT64 Offset=GetNumberFromString(argv[2]);
//Write the data 10MB at a time from STDIN to the file
char *Buffer=new char[MaxSizeToRead];
fseeko64(TheFile, Offset, SEEK_SET); //Seek to the beginning write offset of our file
#ifdef WIN32 //STDIN only needs to be set to binary mode in windows
_setmode(_fileno(stdin), _O_BINARY);
#endif
do
{
size_t AmountRead=fread(Buffer, 1, MaxSizeToRead, stdin); //Read the data from STDIN
fwrite(Buffer, AmountRead, 1, TheFile); //Write the data to the file
}
while(!feof(stdin)); //Keep reading and writing until STDIN is complete
//Cleanup
delete[] Buffer;
fclose(TheFile);
return 1;
}
I needed a command line utility for Bash (for both Windows and Linux) that only outputs bytes between 2 points in a file to STDOUT. head and tail weren’t really cutting it so I figured I’d throw something together. Below is the source code for the result, which I call chunk (Windows Executable).
I compiled the file as c++, but it should be c99 compatible. The file has been tested as compilable for: GCC4 on Slackware, GCC3 on Red Hat, and GCC3 on MingW (Windows [WIN32 should be defined by the compiler]).
Chunk outputs bytes between 2 points in a file to STDOUT. The parameters are:
1) The file
2) The byte offset to start at (hex is supported like 0xA)
3) The number of bytes to output. If not given, the end of the file is assumed.
The source is as follows:
//Copyright 2009 by Dakusan (http://www.castledragmire.com/Copyright). Licensed under Dakusan License v2.0 (http://www.castledragmire.com/Misc/Software_Licenses/Dakusan_License_v2.0.php).
//See http://www.castledragmire.com/Posts/chunk for more information
#define __LARGE64_FILES
#include <stdio.h>
#include <stdlib.h> //strtoull
#ifdef WIN32 //STDOUT only needs to be set to binary mode in windows
#include <io.h> //_setmode
#include <fcntl.h> //_O_BINARY
#endif
typedef unsigned long long UINT64;
const UINT64 MaxSizeToRead=1024*1024*10; //The maximum number of bytes to read at a time to our buffer (Must be < 2^31)
UINT64 GetNumberFromString(const char* S) //Extract both hexidecimal and decimal numbers from a string
{
bool IsHex=S[0]=='0' && (S[1]|32=='x'); //If string starts as 0x, then is a hex number
return strtoull(S+(IsHex ? 2 : 0), NULL, IsHex ? 16 : 10); //Hex number starts after 2 characters and uses base 16
}
int main(int argc, char *argv[], char *envp[])
{
//Determine if proper number of parameters are passed, and if not, output help info
if(argc!=3 && argc!=4)
return fprintf(stderr, "Chunk outputs bytes between 2 points in a file to STDOUT. The parameters are:\n1) The file\n2) The byte offset to start at (hex is supported like 0xA)\n3) The number of bytes to output. If not given, the end of the file is assumed.\n") & 0;
//Open the file and get its length
FILE *TheFile=fopen64(argv[1], "rb");
if(TheFile==NULL)
return fprintf(stderr, "File not found or cannot open file\n") & 0;
fseeko64(TheFile, 0, SEEK_END); //Get the length by seeking to the end
UINT64 FileSize=ftello64(TheFile);
//Determine the requested start offset
UINT64 Offset=GetNumberFromString(argv[2]), SizeToOutput;
if(Offset>=FileSize)
{
fprintf(stderr, "Offset is larger than file's size\n");
fclose(TheFile);
return 0;
}
//Determine the size to read
if(argc==3) //If no final parameter, read to the end of the file
SizeToOutput=FileSize-Offset;
else //Determine from the 3rd parameter
{
SizeToOutput=GetNumberFromString(argv[3]);
if(Offset+SizeToOutput>FileSize)
{
fprintf(stderr, "Requested size is larger than the file, truncating to end of file\n");
SizeToOutput=FileSize-Offset;
}
else if(!SizeToOutput) //If nothing to output, exit prematurely
{
fclose(TheFile);
return 1;
}
}
//Output requested data 10MB at a time from the file to STDOUT
char *Buffer=new char[SizeToOutput>MaxSizeToRead ? MaxSizeToRead : SizeToOutput]; //Only allocate as many bytes to our read buffer as is necessary
fseeko64(TheFile, Offset, SEEK_SET); //Seek to the beginning read offset of our file
#ifdef WIN32 //STDOUT only needs to be set to binary mode in windows
_setmode(_fileno(stdout), _O_BINARY);
#endif
while(SizeToOutput) //Keep reading and outputting until requested data is complete
{
UINT64 SizeToRead=SizeToOutput>MaxSizeToRead ? MaxSizeToRead : SizeToOutput; //Number of bytes to read and write
fread(Buffer, SizeToRead, 1, TheFile); //Read the data
fwrite(Buffer, SizeToRead, 1, stdout); //Write the data to STDOUT
SizeToOutput-=SizeToRead; //Decrease number of bytes we still need to read
}
//Cleanup
delete[] Buffer;
fclose(TheFile);
return 1;
}
Since I just released my AJAX Library, I thought I’d post a useful script that uses it. The function CrossDomainGetURL below uses the AJAX Library to make requests across domains in Firefox. It takes one more parameter (not in order) than the AJAX Library's GetURL function, which is an array of domains to pull cookies from for the AJAX request.
function GetCookiesFromURL(Domains) //Return all the cookies for Domains specified in the Domains array
{
var cookieManager = Components.classes["@mozilla.org/cookiemanager;1"].getService(Components.interfaces.nsICookieManager); //Requires privileges, which is granted in CrossDomainGetURL
var iter=cookieManager.enumerator, CookieList=[], cookie; //The object used to find all cookies, the final list of cookies, and a temporary object
while(iter.hasMoreElements()) //Loop through all cookies
if(((cookie=iter.getNext()) instanceof Components.interfaces.nsICookie) && Domains.indexOf(cookie.host)!=-1) //If a cookie whose host matches one of our domains
CookieList.push(cookie.name+'='+cookie.value); //Add it to our final list
return CookieList.join("; "); //Return the cookie list for the specified domains
}
function CrossDomainGetURL(URL, Data, CookieDomains, ExtraOptions) //See AJAX Library GetURL function. CookieDomains is an array specifying what domains cookies are pulled from for the AJAX call.
{
//Access universal privileges in Firefox (Required to get cookies for other domains, and to use AJAX with other domains). This functionality is lost as soon as this function loses scope.
try { netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect"); }
catch(e) { return alert('Cannot access browser privileges'); }
if(CookieDomains instanceof Array) //If an array of domains is passed to get cookies from...
{
ExtraOptions=((ExtraOptions instanceof Object) ? ExtraOptions : {}); //Make sure extra options is an object
ExtraOptions.AdditionalHeaders=((ExtraOptions.AdditionalHeaders instanceof Object) ? ExtraOptions.AdditionalHeaders : {}); //Make sure extra options has an additional headers object
ExtraOptions.AdditionalHeaders.Cookie=GetCookiesFromURL(CookieDomains); //Get cookies for the domains
}
return GetURL(URL, Data, ExtraOptions); //Do the AJAX Call
}
I am often asked to transfer data sets into MySQL databases, or other formats. In this case, I’ll use a Microsoft Excel file without line breaks in the fields to MySQL as an example. While there are many programs out there to do this kind of thing, this method doesn’t take too long and is a good example use of regular expressions.
First, select all the data in Excel (ctrl+a) and copy (ctrl+c) it to a text editor with regular expression support. I recommend EditPad Pro as a very versatile and powerful text editor.
Next, we need to turn each row into the format “('FIELD1','FIELD2','FIELD3',...),”. Four regular expressions are needed to format the data:
Search
Replace
Explanation
'
\\'
Escape single quotes
\t
','
Separate fields and quote as strings
^
('
Start of row
$
'),
End of row
From there, there are only 2 more steps to complete the query.
Add the start of the query: “INSERT INTO TABLENAME VALUES”
End the query by changing the last row's comma “,” at the very end of the line to a semi-colon “;”.
For example:
a b c
d e f
g h i
would be converted to
INSERT INTO MyTable VALUES
('a','b','c'),
('d','e','f'),
('h','h','i');
Sometimes queries may get too long and you will need to separate them by performing the “2 more steps to complete the query” from above.
After doing one of these conversions recently, I was also asked to make the data searchable, so I made a very simple PHP script for this.
This script lets you search through all the fields and lists all matches. The fields are listed on the 2nd line in an array as "SQL_FieldName"=>"Viewable Name". If the “Viewable Name” contains a pound sign “#” it is matched exactly, otherwise, only part of the search string needs to be found.
<?
$Fields=Array('ClientNumber'=>'Client #', 'FirstName'=>'First Name', 'LastName'=>'Last Name', ...); //Field list
print '<form method=post action=index.php><table>'; //Form action needs to point to the current file
foreach($Fields as $Name => $Value) //Output search text boxes
print "<tr><td>$Value</td><td><input name=\"$Name\" style='width:200px;' value=\"".
(isset($_POST[$Name]) ? htmlentities($_POST[$Name], ENT_QUOTES) : '').'"></td></tr>';//Text boxes w/ POSTed values,if set
print '</table><input type=submit value=Search></form>';
if(!isset($_POST[key($Fields)])) //If search data has not been POSTed, stop here
return;
$SearchArray=Array('1=1'); //Search parameters are stored here. 1=1 is passed in case no POSTed search parameter are ...
//... requested so there is at least 1 WHERE parameter, and is optimized out with the MySQL preprocessor anyways.
foreach($Fields as $Name => $Value) //Check each POSTed search parameter
if(trim($_POST[$Name])!='') //If the POSTed search parameter is empty, do not use it as a search parameter
{
$V=mysql_escape_string($_POST[$Name]); //Prepare for SQL insertion
$SearchArray[]=$Name.(strpos($Value, '#')===FALSE ? " LIKE '%$V%'" : "='$V'"); //Pound sign in the Viewable Name=exact ...
//... value, otherwise, just a partial patch
}
//Get data from MySQL
mysql_connect('SQL_HOST', 'SQL_USERNAME', 'SQL_PASSWORD');
mysql_select_db('SQL_DATABASE');
$q=mysql_query('SELECT * FROM TABLENAME WHERE '.implode(' AND ', $SearchArray));
//Output retrieved data
$i=0;
while($d=mysql_fetch_assoc($q)) //Iterate through found rows
{
if(!($i++)) //If this is the first row found, output header
{
print '<table border=1 cellpadding=0 cellspacing=0><tr><td>Num</td>'; //Start table and output first column header (row #)
foreach($Fields as $Name => $Value) //Output the rest of the column headers (Viewable Names)
print "<td>$Value</td>";
print '</tr>'; //Finish header row
}
print '<tr bgcolor='.($i&1 ? 'white' : 'gray')."><td>$i</td>"; //Start the data field's row. Row's colors are alternating white and gray.
foreach($Fields as $Name => $Value) //Output row data
print '<td>'.$d[$Name].'</td>';
print '</tr>'; //End data row
}
print ($i==0 ? 'No records found.' : '</table>'); //If no records are found, output an error message, otherwise, end the data table
?>
