relative include paths? What's the use?

[Doug]

If I were to write an include with a relative path like

include("../conf/config.php");

What is the use?

As far as I understand it, the path is relative to the first script that
is called by php.

In other words, if the current working directory is /www/ and you were
"executing" a.php in that directory, then a.php included
/www/include/b.php by doing include("include/b.php");, then b.php tried
to include file /www/config/c.php, by doing include("../config/c.php) it
would not work. Instead php would be looking in /config for c.php and
it would not find it (?!).

Relative paths in include directives seem useless, because the paths are
not relative to the file that the include directive is in, like you
would expect them to be. These includes are totally dependant on where
the original file was "run" from.

Can any one shed some light on why relative paths in includes are of
-any- practical use in PHP? Or, is this a bug?

PHP 4.3.4 (cli) (built: Mar 9 2004 11:40:14)

By the way, I am just trying to separate my php project files into a few
directories. I just want to be able to include them without using
absolute paths. These files in these different directories should be
able to include each other.

-d

[Chung Leong]

"Doug" <dougd99@XXXearthlinkXXX.net> wrote in message
news:rsqbc.9130$yN6.6152@newsread2.news.atl.earthl ink.net...

>
> If I were to write an include with a relative path like
>
> include("../conf/config.php");
>
> What is the use?
>
> As far as I understand it, the path is relative to the first script that
> is called by php.

That's because in PHP, an include is an runtime operation and not a
preprocess macro expansion. As an operation, it's perfectly logical that
relative paths are relative to the runtime path and not the source path.
This is certainly not a bug.

To do multiple level relative includes, you can use __FILE__ to determine
the location of the current file, and append the directory path in the
include statement. Example:

<?

$CURRENT_SOURCE_FOLDER = dirname(__FILE__);

require_once("$CURRENT_SOURCE_FOLDER/grumpy.php");
require_once("$CURRENT_SOURCE_FOLDER/sleepy.php");
require_once("$CURRENT_SOURCE_FOLDER/sneezy.php");

....

[Jan Pieter Kunst]

In article <rsqbc.9130$yN6.6152@newsread2.news.atl.earthlink. net>,
Doug <dougd99@XXXearthlinkXXX.net> wrote:

> Can any one shed some light on why relative paths in includes are of
> -any- practical use in PHP? Or, is this a bug?

I use them in the following way:

The first file included in every script is a small config file (in the
same directory as the script itself, so it's guaranteed to be found in a
default PHP setup) which sets the include paths. In that file I have
something like this:

ini_set('include_path', ini_get('include_path') . ':' .
realpath('relative/path/to/include_directory'));

Because of the 'realpath' function, which translates relative paths to
absolute paths, I can copy the directory tree of my application to
another machine and everything will keep working, even if the directory
structure 'above' my application is different.

JP

--
Sorry, <devnull@cauce.org> is een "spam trap".
E-mail adres is <jpk"at"akamail.com>, waarbij "at" = @.

[Rudi Ahlers]

Ok, but how often do you find that even though you don't use relative paths,
your sites doesn't work? Even if the top structure is different from your
development PC than your server / ISP server? I haven't had to use it yet.
In ASP yes, but not really in PHP

--

Kind Regards
Rudi Ahlers
+27 (82) 926 1689

Greater love has no one than this, that he lay down his life for his friends
(John 15:13).
"Jan Pieter Kunst" <devnull@cauce.org> wrote in message
news:devnull-4C0B3E.17212403042004@news1.news.xs4all.nl...
In article <rsqbc.9130$yN6.6152@newsread2.news.atl.earthlink. net>,
Doug <dougd99@XXXearthlinkXXX.net> wrote:

> Can any one shed some light on why relative paths in includes are of
> -any- practical use in PHP? Or, is this a bug?

I use them in the following way:

The first file included in every script is a small config file (in the
same directory as the script itself, so it's guaranteed to be found in a
default PHP setup) which sets the include paths. In that file I have
something like this:

ini_set('include_path', ini_get('include_path') . ':' .
realpath('relative/path/to/include_directory'));

Because of the 'realpath' function, which translates relative paths to
absolute paths, I can copy the directory tree of my application to
another machine and everything will keep working, even if the directory
structure 'above' my application is different.

JP

--
Sorry, <devnull@cauce.org> is een "spam trap".
E-mail adres is <jpk"at"akamail.com>, waarbij "at" = @.

[Doug]

Chung Leong wrote:

> "Doug" <dougd99@XXXearthlinkXXX.net> wrote in message
> news:rsqbc.9130$yN6.6152@newsread2.news.atl.earthl ink.net...
>

>>If I were to write an include with a relative path like
>>
>>include("../conf/config.php");
>>
>>What is the use?
>>
>>As far as I understand it, the path is relative to the first script that
>>is called by php.

>
>
> That's because in PHP, an include is an runtime operation and not a
> preprocess macro expansion. As an operation, it's perfectly logical that
> relative paths are relative to the runtime path and not the source path.
> This is certainly not a bug.
>
> To do multiple level relative includes, you can use __FILE__ to determine
> the location of the current file, and append the directory path in the
> include statement. Example:
>
> <?
>
> $CURRENT_SOURCE_FOLDER = dirname(__FILE__);
>
> require_once("$CURRENT_SOURCE_FOLDER/grumpy.php");
> require_once("$CURRENT_SOURCE_FOLDER/sleepy.php");
> require_once("$CURRENT_SOURCE_FOLDER/sneezy.php");

Regardless of the implementatation details (runtime vs. preprocess),
they could've done it either way. Just like the makers of gcc could
have chose to do it either way. The PHP programmers chose to make the
path relative to the first script that is called by php.

In your example, you changed the paths to be absolute. That makes it so
that the file included would be the file that most people expect will be
included in the first place.

Could some one give me a practical example of a -relative- path being
used in PHP?


-d

[Jan Pieter Kunst]

In article <r8idnTOMSfZ9fvPdRVn-hg@is.co.za>,
"Rudi Ahlers" <SP4M_Rudi@SP4M_Bonzai.org.za_SP4M> wrote:

> Ok, but how often do you find that even though you don't use relative paths,
> your sites doesn't work? Even if the top structure is different from your
> development PC than your server / ISP server? I haven't had to use it yet.
> In ASP yes, but not really in PHP

Well, on my development machine I have my sites in my home folder
(~/Sites on Mac OS X) and on the server (also Mac OS X) they are in
/Library/WebServer/Documents.

It was also very convenient when we went from Linux (webserver in
/usr/local/httpd/htdocs) to Mac OS X -- I could simply copy my sites
without breaking anything.

JP

--
Sorry, <devnull@cauce.org> is een "spam trap".
E-mail adres is <jpk"at"akamail.com>, waarbij "at" = @.

[Chung Leong]

"Doug" <dougd99@XXXearthlinkXXX.net> wrote in message
news:HDCbc.9139$NL4.2247@newsread3.news.atl.earthl ink.net...

> Regardless of the implementatation details (runtime vs. preprocess),
> they could've done it either way. Just like the makers of gcc could
> have chose to do it either way. The PHP programmers chose to make the
> path relative to the first script that is called by php.

The fact that it's an runtime operation makes a big difference. Suppose I
write a function that include a file:

function CustomInclude($path) {
include($path);
echo "<!-- including $path -->";
}

And suppose I place this function in /chung/utilities/useless/functions.php.
When I pass a relative path to this function in some project, I certainly
wouldn't want the path to be relative to the file containing the function.

[Doug]

Chung Leong wrote:

> "Doug" <dougd99@XXXearthlinkXXX.net> wrote in message
> news:HDCbc.9139$NL4.2247@newsread3.news.atl.earthl ink.net...
>

>>Regardless of the implementatation details (runtime vs. preprocess),
>>they could've done it either way. Just like the makers of gcc could
>>have chose to do it either way. The PHP programmers chose to make the
>>path relative to the first script that is called by php.

>
>
> The fact that it's an runtime operation makes a big difference. Suppose I
> write a function that include a file:
>
> function CustomInclude($path) {
> include($path);
> echo "<!-- including $path -->";
> }
>
> And suppose I place this function in /chung/utilities/useless/functions.php.
> When I pass a relative path to this function in some project, I certainly
> wouldn't want the path to be relative to the file containing the function.

good point.

-d

[Unregistered]

I created a code to always make the links in the included file as relative. This takes care of the nested directories. To do this, first add the following code to the file that is included.

$path_array = explode("/", $_SERVER[SCRIPT_FILENAME]);
$my_rel_html_path = "";
if (count($path_array) == 5) /* 5 would be the length if you look at the regular path name in web server. In mine it was /home/abc/public_html. When this is exploded it is 4 length of array. The fifth is the fact that when you explode SCRIPT_FILENAME, it will include the file name as well. In essence, based on the server setup, you will just need to tweak the digit 5 to which ever location is the root directory of the website.*/
{
$my_rel_html_path = "./";
}
else
{
for ($i=5; $i < count($path_array); $i++)
{
$my_rel_html_path .= "../";
}
}
echo $my_rel_html_path;


Then use the $my_rel_html_path before any link value in HTML. For example,

<img src="<?php echo($my_rel_html_path);?>images/arrow.jpg">
OR
<a href="<?php echo($my_rel_html_path);?>home.php">

No matter which page is calling the included file, the links in the included file will always work.