Articles Php Functions
Php Functions
PHP and Shell Scripting: Using Pipes - Page 2
by: Peter Shaw
|
February 12, 2009
As you can see the outputs are very similar, but not identical, however this is not an article about shell programming in general, it's about putting PHP to some advanced uses. You can see from the examples above that commands are joined with the vertical bar character '|' as this is the pipe character, and to cut this short basically means take the output of one command and feed to the next via the standard input stream.
This means if we read the standard input stream using the php file stream 'php://stdin' then we can use PHP to construct blocks of code that can participate in the filter chain.
Enough talking already, give us some code!!!!
Ok ok, I hear you. So by way of an example to show what IĀm on about, we'll put together a small example under Linux that shows what those file permission flags in a file listing mean.
First, if we do an 'ls -al' we should see something like this:
<code>
drwx------ 2 shawty users 4096 2006-04-10 23:51 .ssh
-rw-r--r-- 1 shawty users 193 2007-10-25 10:43 staaus.cap
-rw-r--r-- 1 shawty users 11627 2007-10-27 14:05 staceymail2
-rw-r--r-- 1 shawty users 18737 2007-10-28 00:24 staceymail3
-rw-r--r-- 1 shawty users 34040 2007-10-28 16:10 staceymail4
-rw-r--r-- 1 shawty users 182891 2007-10-26 09:28 stacymail
-rw-r--r-- 1 shawty shawty 3642 2008-10-29 17:02 startup
-rw-r--r-- 1 shawty shawty 4124 2008-10-29 17:03 startup-org
-rw-r--r-- 1 shawty users 55 2006-06-03 01:51 suck.newrc
-rw-r--r-- 1 shawty users 50 2006-06-03 01:47 sucknewsrc
-rw-r--r-- 1 shawty users 0 2008-05-15 17:20 .sudo_as_admin_successful
-rw-r--r-- 1 shawty users 23067 2006-10-12 22:34 telnet.pl
-rw-r--r-- 1 shawty users 9231834 2006-04-18 14:21 termine
</code>
The first thing we need to do here is to read this into a PHP script.
<code>
<?php
// Open PHP's standard input stream
$input_stream = fopen("php://stdin","r");
// Array to store the received data
$lines = array();
// Loop & process while we receive lines
while($line = fgets($input_stream,4096)) // Note 4k lines, should be ok for most purposes
{
//Store each line in the array, ensuring we chop off the line ends
$lines[] = trim($line);
}
fclose($input_stream);
print_r($lines);
?>
</code>
If you run this from a Linux command line using 'ls -al | php -q fancydir.php' (replace php file name as required), you'll get something like the following:
<code>
shawty@poweredge:~/Articles_PHP$ ls -al ../ | php -q fancydir.php
Array
(
[0] => total 54676
[1] => drwxr-xr-x 46 shawty users 4096 2009-01-29 20:01 .
[2] => drwxr-xr-x 14 root root 4096 2009-01-13 17:17 ..
[3] => -rw-r--r-- 1 shawty users 1 2006-11-15 02:24 2
[4] => drwxr-xr-x 10 shawty users 4096 2008-05-14 17:11 20gdrive
[5] => drwxr-x--- 6 shawty users 4096 2007-04-30 16:14 4grec1
[6] => drwx------ 2 shawty users 4096 2006-05-14 17:31 a.b.p.v.files
[7] => -rw-r--r-- 1 shawty users 1863991 2006-03-06 14:24 abs-guide.pdf
[8] => -rw-r--r-- 1 shawty users 0 2006-05-23 22:42 .addressbook
[9] => -rw------- 1 shawty users 2285 2006-05-23 22:42 .addressbook.lu
[10] => drwx------ 2 shawty users 4096 2008-05-15 17:42 .aptitude
[11] => drwxr-xr-x 2 shawty shawty 4096 2009-01-29 20:01 Articles_PHP
[12] => drwxr-xr-x 3 shawty users 4096 2006-06-11 01:34 baks
[13] => -rw------- 1 shawty users 15190 2009-01-29 12:56 .bash_history
[14] => -rw-r--r-- 1 shawty users 220 2008-05-15 16:41 .bash_logout
[15] => -rw-r--r-- 1 shawty users 2298 2008-05-15 16:41 .bashrc
[16] => drwxr-xr-x 2 shawty users 4096 2006-08-07 14:39 belkinbt
[17] => drwx------ 2 shawty users 4096 2006-08-22 21:16 .cedit
==SNIP==
</code>
As you can see, the directory listing is in an array, line by line as sent to the script. We can now use this array to go over each line and redisplay it, something like this:
<code>
$count = 1;
foreach($lines as $line)
{
print $count . " : " . $line . "\n";
$count++;
}
</code>
This would give you a number listing something like the following:
<code>
1 : drwxr-xr-x 46 shawty users 4096 2009-01-29 20:01 .
2 : drwxr-xr-x 14 root root 4096 2009-01-13 17:17 ..
3 : -rw-r--r-- 1 shawty users 1 2006-11-15 02:24 2
4 : drwxr-xr-x 10 shawty users 4096 2008-05-14 17:11 20gdrive
5 : drwxr-x--- 6 shawty users 4096 2007-04-30 16:14 4grec1
6 : drwx------ 2 shawty users 4096 2006-05-14 17:31 a.b.p.v.files
7 : -rw-r--r-- 1 shawty users 1863991 2006-03-06 14:24 abs-guide.pdf
8 : -rw-r--r-- 1 shawty users 0 2006-05-23 22:42 .addressbook
</code>
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