PHP version comparison function version_compare ()

PHP version, generally use version_compare () function, help documentation see: http://php.net/manual/en/function.version-compare.php
Purpose: Compares two "PHP-standardized" version number
Strings.
Syntax:
Version_compare

(String
$ Version1

, String
$ Version2

[, String
$ Operator

])
Description:Version_compare ()

Compares two
"PHP-standardized"
Version number strings. This is useful if you wowould like to write
Programs
Working only on some versions of PHP.

The function first replaces_
,-
And
+
With a dot.
In the version
Strings and also inserts dots.
Before and after any
Non number so that for example '4. 3.2rc1 'becomes' 4. 3.2.rc.1 '. Then
It
Splits the results like if you were using explode ('.', $ ver). Then it
Compares the parts starting from left to right. If a part contains
Special version strings these are handled in the following order:
Any string not found in this list
<
Dev
<Alpha
=
A
<Beta
=
B
<RC
=
RC
<#
<
PL
=P
. This way not only versions
With different levels like '4. 1' and '4. 1.2 'can be compared but also
Any
PHP specific version containing development state.

The third optional parameter is a comparison character:

If you specify the third optionalOperator

Argument, you can test for a particle relationship.
Possible operators are:<
,
Lt
,<=
,
Le
,>
,
GT
,> =
,
Ge
,=
,
=
,EQ
,
! =
,<>
,
Ne
Respectively.

This parameter is case-sensitive, so values shoshould be lowercase.

Return Value:

By default,Version_compare ()

Returns
-1
If the first version is lower than the second,
0
If they are equal, and
1
If the second is lower.

When using the OptionalOperator

Argument,
Function will returnTrue

If the relationship is
One specified
By the operator,False

Otherwise.

The following example shows how to use version_compare:


<?php

if (
version_compare
(
PHP_VERSION
, 
'6.0.0'
) >= 
0
) {
    echo 
'I am at least PHP version 6.0.0, my version: ' 
. 
PHP_VERSION 
. 
"/n"
;
}

if (
version_compare
(
PHP_VERSION
, 
'5.3.0'
) >= 
0
) {
    echo 
'I am at least PHP version 5.3.0, my version: ' 
. 
PHP_VERSION 
. 
"/n"
;
}

if (
version_compare
(
PHP_VERSION
, 
'5.0.0'
, 
'>='
)) {
    echo 
'I am using PHP 5, my version: ' 
. 
PHP_VERSION 
. 
"/n"
;
}

if (
version_compare
(
PHP_VERSION
, 
'5.0.0'
, 
'<'
)) {
    echo 
'I am using PHP 4, my version: ' 
. 
PHP_VERSION 
. 
"/n"
;
}

?>

Recently, when installing the Nagios chart monitoring plug-in PNP, an error occurs: Kohana requires PHP 5.2 or newer. Check the page source code and find the following statement:
Version_compare (php_version, '5. 2', '<') and exit ('kohana requires PHP 5.2 or newer .');
That is, exit if the version is not satisfied.