3

It's functionality is so strong that I worry about its stability and performance.

What do you think?

UPDATE

What I'm doing is this:

    $old_dir = getcwd();
    chdir( dirname($included_file) );
    include ( $included_file );
    chdir( $old_dir );

Essentially it just does include ( $included_file );,but inside that $included_file it can't find 3.php which is in the same directory as itself is in,so I manually set the cwd and it works.But it would be nice if I find the reason why it can't find.As for why debug_backtrace is needed,it's because 3.php is included by another func,since the relative path doesn't work,it has to use debug_backtrace to get the including file path,finally using the absolute path as mentioned below.

It's not easy to reproduce,as the above code is in the context of a method,and much more..If no one else has met this kinda problem I'd like to just stop here,anyway,the cost is just the 3 extra lines,not a big deal.

user187291
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user198729
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    Could you explain a bit further what you're trying to achieve? Why do you want to use this function? – Crozin Mar 13 '10 at 12:54
  • Take a look at the accepted answer of this post:http://stackoverflow.com/questions/2438149/how-to-get-the-absolute-path-of-the-calling-file-in-a-function-thats-called-in-p – user198729 Mar 13 '10 at 12:57
  • But that doesn't explain what it's for and what other (maybe better) alternatives would be. Could be as simple as `call(__FILE__);` – VolkerK Mar 13 '10 at 13:01
  • No,`__FILE__` returns the file where the function is defined,not called. – user198729 Mar 13 '10 at 13:03
  • And the primary cause is related with this post:http://stackoverflow.com/questions/2438155/which-directories-does-php-check-when-including-a-relative-path-with-include – user198729 Mar 13 '10 at 13:06
  • "No,\_\_FILE\_\_ returns the file where the function is defined" - `call(__FILE__);` is the function _call_ not the definition. The declaration would be `function call($path) ....` – VolkerK Mar 13 '10 at 13:08
  • But I need to get the calling file in body part(`{}`) of `call()`,not by passing parameters. – user198729 Mar 13 '10 at 13:19
  • And that was my question: Why? Because if we do not know why we also don't know what viable alternatives there might be. For all I knew passing a parameter could have been perfectly fine. Ok, I've looked at question #2438155. And imho debug_backtrace() would be an ugly, most likely avoidable hack for this scenario. – VolkerK Mar 13 '10 at 13:45
  • @stereofrog,what I want to do is just:get the calling file's abs path,and use `chdir()` to change to the same directory,to fix the problem that **sometimes it won't find even though it's in the same directory**,refer to it to understand the whole picture:http://stackoverflow.com/questions/2438155/which-directories-does-php-check-when-including-a-relative-path-with-include – user198729 Mar 13 '10 at 14:03
  • @stereofrog,I understand what you mean.But it's a feature,to let the user just provide a filename,indicating it's in the same directory as the including file is in – user198729 Mar 13 '10 at 14:18
  • @stereofrog,I've provided more information.I **do** understand your meaning though. – user198729 Mar 13 '10 at 14:29

3 Answers3

6

debug_backtrace is relatively expensive in my experience, so you should be careful it is not used in loops (e.g. in a custom error handler that catches warnings or notices and performs a backtrace every time).

For any kind of error logging, I think it's pretty invaluable, and because it's going to be called only once, definitely not a performance problem. It is surely always good to include a backtrace in an error report.

I can't see why there would be any specific issues with this function's stability (i.e. calling it causing another crash), I've never heard of any problems. The only "gotcha" I can see is this note in the User Contributed Notes when using objects as function parameters that have no _toString method defined.

Of course, you should never output the results of a backtrace to the end user - that goes without saying.

Pekka
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Well, considering its name, I'm not sure I would use it as a "normal" part of my application -- even though I don't remember having read anything which said that it was either good nor bad.


I don't really know what you mean about "serious usage", but :

  • If you need that function for your application to work, it migh indicate some problem in your design
  • This function can be useful in an error-handler, when you want to log how/where an error happened : it will make the log files more useful, when it comes to tracking down the sources of errors

Though, not sure that "error logging" corresponds to your definition of serious usage ?

Pascal MARTIN
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Ok, from my understanding, the problem is following

You've got a php file, let's call it "main.php". In "main.php" you're including "A.php" from some directory:

# in "main.php"
include '/some/dir/A.php';

A.php, in turn, includes 'B.php', which is in the same directory as A.php

# in "A.php"
include 'B.php';

the problem: since "/some/dir/" (where A and B reside) is not the current for "main.php", php does not see B.php from A.php

the solution: in A.php use an absolute full path to /some/dir. Either hardcode it or obtain it dynamically via dirname(__FILE__)

# in "A.php"
include dirname(__FILE__) .'/B.php';
user187291
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