By Mark Paget
Want to display PHP code with syntax highlighting (colors). This helps with debugging, etc.
Within PHP you can nicely display colorful text, which can be very useful for debugging or just to showcase your code.
We simply use the highlight_file function within PHP, like this below.
<?php highlight_file("transform.php"); ?>
For a real-life demo, take a look here:
You want to display a counter on your web page, but you do not want to use a db.
All you need to make this work is echo “1” into a file called counter and ensure the web user has write access. For example: $ echo 1 > counter; chmod 777 counter;
<?php
$fh=fopen(“/tmp/counter.txt”, “r”);
$cnt=fread($fh,filesize(“/tmp/counter.txt”));
fclose($fh);
$fh=fopen(“/tmp/counter.txt”, “w+”);
if(fputs($fh,($cnt+1))) { print(“You are visitor: $cntn”); }
fclose($fh);
?>
[/example]
[tags]PHP Guest Book, PHP Coding School[/tags]
You want to open save the contents of a file, into a variable in PHP.
Simple demo on opening and reading contents of files in PHP.
Script under example tab takes filename as a parameter, then opens it read-only and reads contents in data variable.
Then it echoes a header and footer line, with the data in the middle.
<?php
$filename=$argv[1];
$FH=fopen("$filename","r") or die("could not open $filenamen");
while(!feof($FH)) { $data.=fgets($FH); }
fclose($FH);
echo "###### beginning of $filename ######n";
echo "$data";
echo "n###### end of $filename ######n";
exit(0);
?>
Here is a run through:
$ php -q readfiles.php rhyme.txt
###### beginning of rhyme.txt ######
Mary had a little lamb,
It was always bleating.
###### end of rhyme.txt ######
[tags]PHP file handling, PHP Coding School[/tags]
You want to intersperse HTML with PHP code.
Just getting back to basics, this is a very simple demo
of how to implement PHP code along with HTML.
<html><head>....
<body>
<h1>Hello World</h1>
<?php if($_GET[runit]) { ?>
<b>This will get displayed if ?runit=yes is
appended to the web users request</b>
<?php } else { ?>
nothing to see here ... :)
<?php } ?>
<body><html>
[tags]Interperse HTML in PHP, PHP Coding School[/tags]
You want to create an array, then traverse it.
Following up from part one – working with arrays.
To spin through all elements in our names array, here is the code below.
<?php
$count=count($names);
for ($i=0;$i<$count;$i++) { print($names[$i]."n"); }
?>
Then for our string index array (hash):
<?php
while(list($k,$v)=each($addresses)) {
echo "$k lives at $vn";
}
?>
You want to work with string index arrays. Sometimes called Hashes.
PHP can handle number or string indexed arrays.
Arrays can be initialized in a number of ways. For example:
Basic array assignment and initialization, without specify numbers or strings:
<?php
$names[]="joe";
$names[]="john";
$names[]="jim";
?>
Specifically assigning values to numbered elements in the names array:
<?php
$names[0]="joe";
$names[1]="john";
$names[2]="jim";
?>
Quicker way to assign values to names array:
$names=array("joe","john","jim");
Assigning values to a string indexed array – or hash (key and value pairs):
<?php
$addresses=array(
"joe" => "1 Marble Street",
"john" => "12 Marble Street",
"jim" => "23 Marble Street"
);
?>
You want to perform regular expression with PHP.
Again PHP implementation of regular expression is very similar to Perl.
In the simpliest form, pattern matching:
$ php -q<<EOT
<?php
$str="hello world";
if(ereg("world","$str")) {
echo("got a match");
}
?>
EOT
got a match
Similarly eregi operates the same, just it is case insensitive.
$ php -q<<EOT
<?php
$str="hello world";
if(eregi("WORLD","$str")) {
echo("got a matchn");
}
?>
EOT
got a match
[tags]PHP ereg, PHP eregi, PHP Coding School[/tags]
You want to perform string manipulation with PHP.
Following on from the intro post, see the example tab for some more demos on PHP string manipulation.
Counting the number of characters in a string:
strlen
$ php -q<<EOT
<?php
echo(strlen("Hello World")."n");
?>
EOT
11
Converts an ASCII code to a character:
chr
$ php -q<<EOT
<?php
echo(chr(65)."n");
?>
EOT
A
[tags]PHP strlen, PHP chr, PHP Coding School[/tags]
Substituting and trimming string variables in PHP.
Similar to Perl, PHP has an extensive library of functions.
See the example tab for a few simple examples, showing the basic syntax.
substr
$ php -q<<EOT
<?php
echo(substr("Hello World",0,4)."n");
?>
EOT
Hell
trim
$ php -q<<EOT
<?phpecho(trim(" Hello World ")."n");
?>
EOTHello World
[tags]PHP substr, PHP trim, PHP Coding School[/tags]
