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PHP Warning: extract() expects parameter 1 to be array

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  PHP Warning:  extract() expects parameter 1 to be array Alla <modelling.data@gmail.com> - 2016-08-20 09:15 -0700
    Re: PHP Warning:  extract() expects parameter 1 to be array "R.Wieser" <address@not.available> - 2016-08-20 18:48 +0200
      Re: PHP Warning:  extract() expects parameter 1 to be array Alla <modelling.data@gmail.com> - 2016-08-20 10:16 -0700
        Re: PHP Warning: extract() expects parameter 1 to be array "Christoph M. Becker" <cmbecker69@arcor.de> - 2016-08-20 19:28 +0200
          Re: PHP Warning: extract() expects parameter 1 to be array Alla <modelling.data@gmail.com> - 2016-08-20 11:00 -0700
        Re: PHP Warning:  extract() expects parameter 1 to be array "R.Wieser" <address@not.available> - 2016-08-20 21:05 +0200
      Re: PHP Warning:  extract() expects parameter 1 to be array Alla <modelling.data@gmail.com> - 2016-08-20 10:58 -0700
    Re: PHP Warning:  extract() expects parameter 1 to be array Tim Streater <timstreater@greenbee.net> - 2016-08-20 18:21 +0100
      Re: PHP Warning: extract() expects parameter 1 to be array "Christoph M. Becker" <cmbecker69@arcor.de> - 2016-08-20 20:16 +0200
        Re: PHP Warning: extract() expects parameter 1 to be array "R.Wieser" <address@not.available> - 2016-08-20 21:26 +0200
          Re: PHP Warning: extract() expects parameter 1 to be array Tim Streater <timstreater@greenbee.net> - 2016-08-20 22:05 +0100
        Re: PHP Warning: extract() expects parameter 1 to be array Alla <modelling.data@gmail.com> - 2016-08-20 22:39 -0700
          Re: PHP Warning: extract() expects parameter 1 to be array Tim Streater <timstreater@greenbee.net> - 2016-08-21 10:26 +0100
            Re: PHP Warning: extract() expects parameter 1 to be array Jerry Stuckle <jstucklex@attglobal.net> - 2016-08-21 10:10 -0400
            Re: PHP Warning: extract() expects parameter 1 to be array Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-21 16:55 +0100
              Re: PHP Warning: extract() expects parameter 1 to be array Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-08-22 21:34 +0200
                Re: PHP Warning: extract() expects parameter 1 to be array Jerry Stuckle <jstucklex@attglobal.net> - 2016-08-22 19:13 -0400
                  Re: PHP Warning: extract() expects parameter 1 to be array Matthew Carter <m@ahungry.com> - 2016-08-23 01:26 -0400
                    Re: PHP Warning: extract() expects parameter 1 to be array Jerry Stuckle <jstucklex@attglobal.net> - 2016-08-23 08:08 -0400

#16950 — PHP Warning: extract() expects parameter 1 to be array

Hello!

I have written a small file that extracts information from a txt file passed in as a command line
argument, and inserts all information, line by line, into sql table. When I run the program, I get
a warning:

PHP Warning:  extract() expects parameter 1 to be array, boolean given in /home/ubuntu/workspace/pset8/bin/import on line 30
PHP Stack trace:
PHP   1. {main}() /path/to/file:0
PHP   2. extract() /path/to/file:30

Warning: extract() expects parameter 1 to be array, boolean given in /path/to/file on line 30

Call Stack:
    0.0015     241368   1. {main}() /path/to/file:0
   20.7551     334832   2. extract() /path/to/file:30

Line 30 is this one   extract($new_entry); 

I have checked the extract() function, and had some issues with it, which are now resolved 
thanks to great help I received here. I have checked mysql connection, and it's fine.
Now, even though I get this warning, which I don't understand,
sql table is filled in with the data from txt file, and I don't get an error message at any of the passes 
of the while loop. 

Here is my code. I will be grateful for your help.

<?php
    require(__DIR__ . "/../includes/config.php");
    
    if($argc < 2)
        echo "Please, provide a path to a file\n";
    else
    {
        $file = $argv[1];
    
        if(!file_exists($file))
            echo "Sorry, there is no such file $file\n";
        else if(!($open_file = fopen($file, "r")))
            echo "Sorry, couldn't open $file\n";
        else if(!is_readable($file))
            echo "$file is not readable\n";
        else if(filesize($file)==0)
            echo "Seems there is not content in the file $file\n";
        
        else
        {
            while(!feof($open_file))
            {
                $new_entry = fgetcsv($open_file, 0, "\t");
                // var_dump($new_entry);
        
                extract($new_entry); 

                $entry0 = $new_entry[0];
                $entry1 = $new_entry[1];  
                $entry2 = $new_entry[2]; 
                $entry3 = $new_entry[3]; 
                $entry4 = $new_entry[4];
                $entry5 = $new_entry[5];
                $entry6 = $new_entry[6];
                $entry7 = $new_entry[7];
                $entry8 = $new_entry[8];
                $entry9 = $new_entry[9];
                $entry10 = $new_entry[10];
                $entry11 = $new_entry[11];
            
           //below is a customized query function from a library that is included by config.php

                $row = query("INSERT INTO `places`(`country_code`, `postal_code`, `place_name`,
                `admin_name1`, 
                `admin_code1`, `admin_name2`, `admin_code2`, `admin_name3`, `admin_code3`, `latitude`, 
                 `longitude`, 
                `accuracy`) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)", $entry0, $entry1, $entry2, $entry3, $entry4, 
                $entry5, $entry6, $entry7, $entry8, $entry9, $entry10, $entry11);
                
                if($row < 1)
                    exit("Unable to extract data");
            }
            fclose($open_file);
        }
    }
?>
Thank you very much! 

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#16951

Alla,

> When I run the program, I get a warning:
>
> PHP Warning:  extract() expects parameter 1 to be array, boolean
> given in /home/ubuntu/workspace/pset8/bin/import on line 30
...
> Line 30 is this one   extract($new_entry);

And that "$new_entry" is the result of fgetcsv(), a few lines above it.

Looking at the docs to fgetcsv() I see that it indeed is capable of
returning a boolean, and does that in cases of an error or when encountering
an EOF.

In other words: its possible that fgetcsv() either has got a problem with
converting a read line OR the "while(!feof($open_file))" doesn't detect an
eof, but fgetcsv() does (could happen when the file "ends" with whitespace
before the real end is encountered).

What you need to do is to take that boolean seriously, and deal with it.
For example by first checking if the result value is actually False, and if
so check the file if an EOF is encountered.

If not you might have encountered a non-covertable line, and (possibly) need
to abort.

Hope that helps.

Regards,
Rudy Wieser


-- Origional message:
Alla <modelling.data@gmail.com> schreef in berichtnieuws
2d416b5e-e923-4d44-bcbf-6956d2436ef2@googlegroups.com...
> Hello!
>
> I have written a small file that extracts information from a txt file
passed in as a command line
> argument, and inserts all information, line by line, into sql table.
When I run the program, I get
> a warning:
>
> PHP Warning:  extract() expects parameter 1 to be array, boolean given in
/home/ubuntu/workspace/pset8/bin/import on line 30
> PHP Stack trace:
> PHP   1. {main}() /path/to/file:0
> PHP   2. extract() /path/to/file:30
>
> Warning: extract() expects parameter 1 to be array, boolean given in
/path/to/file on line 30
>
> Call Stack:
>     0.0015     241368   1. {main}() /path/to/file:0
>    20.7551     334832   2. extract() /path/to/file:30
>
> Line 30 is this one   extract($new_entry);
>
> I have checked the extract() function, and had some issues with it, which
are now resolved
> thanks to great help I received here. I have checked mysql connection, and
it's fine.
> Now, even though I get this warning, which I don't understand,
> sql table is filled in with the data from txt file, and I don't get an
error message at any of the passes
> of the while loop.
>
> Here is my code. I will be grateful for your help.
>
> <?php
>     require(__DIR__ . "/../includes/config.php");
>
>     if($argc < 2)
>         echo "Please, provide a path to a file\n";
>     else
>     {
>         $file = $argv[1];
>
>         if(!file_exists($file))
>             echo "Sorry, there is no such file $file\n";
>         else if(!($open_file = fopen($file, "r")))
>             echo "Sorry, couldn't open $file\n";
>         else if(!is_readable($file))
>             echo "$file is not readable\n";
>         else if(filesize($file)==0)
>             echo "Seems there is not content in the file $file\n";
>
>         else
>         {
>             while(!feof($open_file))
>             {
>                 $new_entry = fgetcsv($open_file, 0, "\t");
>                 // var_dump($new_entry);
>
>                 extract($new_entry);
>
>                 $entry0 = $new_entry[0];
>                 $entry1 = $new_entry[1];
>                 $entry2 = $new_entry[2];
>                 $entry3 = $new_entry[3];
>                 $entry4 = $new_entry[4];
>                 $entry5 = $new_entry[5];
>                 $entry6 = $new_entry[6];
>                 $entry7 = $new_entry[7];
>                 $entry8 = $new_entry[8];
>                 $entry9 = $new_entry[9];
>                 $entry10 = $new_entry[10];
>                 $entry11 = $new_entry[11];
>
>            file://below is a customized query function from a library that
is included by config.php
>
>                 $row = query("INSERT INTO `places`(`country_code`,
`postal_code`, `place_name`,
>                 `admin_name1`,
>                 `admin_code1`, `admin_name2`, `admin_code2`,
`admin_name3`, `admin_code3`, `latitude`,
>                  `longitude`,
>                 `accuracy`) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
$entry0, $entry1, $entry2, $entry3, $entry4,
>                 $entry5, $entry6, $entry7, $entry8, $entry9, $entry10,
$entry11);
>
>                 if($row < 1)
>                     exit("Unable to extract data");
>             }
>             fclose($open_file);
>         }
>     }
> ?>
> Thank you very much!

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#16952

Ruby, thank you very much. I have added the lines below to check what's causing 
the issue:

else
        {
            $row_number = 0;
            while(!feof($open_file))
            {
                $new_entry = fgetcsv($open_file, 0, "\t");
                // var_dump($new_entry);
                $row_number++;
                
                if($new_entry == FALSE)
                    exit ("A problem reading data from the file; row number $row_number\n");
                if($new_entry == NULL)
                {
                    echo "The line $row_number doesn't contain any data\n";
                    continue;
                }
                
                extract($new_entry); 
......
and I have found the problem - the last line in txt, i.e. 40796 line, is an empty one, it 
contains no data, hence $new_entry is an empty string at that last while loop iteration -
nothing to extract(). 
Thank you very much for your help!

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#16954 — Re: PHP Warning: extract() expects parameter 1 to be array

On 20.08.2016 at 19:16, Alla wrote:

> Ruby, thank you very much. I have added the lines below to check what's causing 
> the issue:
> 
> else
>         {
>             $row_number = 0;
>             while(!feof($open_file))
>             {
>                 $new_entry = fgetcsv($open_file, 0, "\t");
>                 // var_dump($new_entry);
>                 $row_number++;
>                 
>                 if($new_entry == FALSE)

This tests doesn't work as you expect.  Actually, it will be true for
$new_entry === NULL and all other values that convert to boolean false.

I suggest to read the "Comparison Operators" section in the PHP manual
(<http://php.net/manual/en/language.operators.comparison.php>) and also
the section on "Type Juggling"
(<http://php.net/manual/en/language.types.type-juggling.php>).

>                     exit ("A problem reading data from the file; row number $row_number\n");
>                 if($new_entry == NULL)
>                 {
>                     echo "The line $row_number doesn't contain any data\n";
>                     continue;
>                 }
>                 
>                 extract($new_entry); 
> ......
> and I have found the problem - the last line in txt, i.e. 40796 line, is an empty one, it 
> contains no data, hence $new_entry is an empty string at that last while loop iteration -
> nothing to extract(). 

Generally, I suggest to use a while loop as shown in the example #1 in
the PHP manual:
<http://php.net/manual/en/function.fgetcsv.php#refsect1-function.fgetcsv-examples>.

-- 
Christoph M. Becker

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#16956 — Re: PHP Warning: extract() expects parameter 1 to be array

Christoph, 
Thank you very much! I will follow your advice.

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#16958

Alla,

> Ruby, thank you very much. I have added the lines below
> to check what's causing the issue:
...
> and I have found the problem - the last line in txt, i.e. 40796 line,
> is an empty one, it contains no data, hence $new_entry is an empty
> string at that last while loop iteration - nothing to extract().

I already expected as much (have run into the same problem myself), but
couldn't be sure.  Glad you found it.

A remark at the code snippets Christoph posted a link to though: none of the
examples seem to check what caused the fgetcsv() function to return a False.
It could be an EOL, but it could be as well be a parsing or other error ...

You really should check, otherwise you could accept a partially processed
input file (with a problem on the last-read line) as fully done.  Not good.
:-|

> Rudy! Please, please, forgive me for making typos in your name -
> I have done that two times already; this is extremely shameful.
> Please, believe me that it was not due to lack of respect; these
> are pure typos. I am truly sorry!

Don't worry about it, I already was assuming you just made a mistake.  I'm
just glad you noticed it. :-)

Regards,
Rudy Wieser


-- Origional message:
Alla <modelling.data@gmail.com> schreef in berichtnieuws
6ee0e256-b008-4d76-8336-3eac5e4fe4c7@googlegroups.com...
> Ruby, thank you very much. I have added the lines below to check what's
causing
> the issue:
>
> else
>         {
>             $row_number = 0;
>             while(!feof($open_file))
>             {
>                 $new_entry = fgetcsv($open_file, 0, "\t");
>                 // var_dump($new_entry);
>                 $row_number++;
>
>                 if($new_entry == FALSE)
>                     exit ("A problem reading data from the file; row
number $row_number\n");
>                 if($new_entry == NULL)
>                 {
>                     echo "The line $row_number doesn't contain any
data\n";
>                     continue;
>                 }
>
>                 extract($new_entry);
> ......
> and I have found the problem - the last line in txt, i.e. 40796 line, is
an empty one, it
> contains no data, hence $new_entry is an empty string at that last while
loop iteration -
> nothing to extract().
> Thank you very much for your help!

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#16955

Rudy! Please, please, forgive me for making typos in your name - I have done that two times
already; this is extremely shameful. Please, believe me that it was not due to lack of respect; 
these are pure typos. I am truly sorry! 

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#16953

In article <2d416b5e-e923-4d44-bcbf-6956d2436ef2@googlegroups.com>,
Alla <modelling.data@gmail.com> wrote:

>                $new_entry = fgetcsv($open_file, 0, "\t");

Why are you not checking that fgetcsv didn't return a boolean?

I could also ask why your program is such a convoluted if/then/else
mess but I can't be bothered.

-- 
"I am enclosing two tickets to the first night of my new play; bring a
friend.... if you have one." - GB Shaw to Churchill "Cannot possibly
attend first night, will attend second...  if there is one." - Winston
Churchill, in response.

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#16957 — Re: PHP Warning: extract() expects parameter 1 to be array

On 20.08.2016 at 19:21, Tim Streater wrote:

> In article <2d416b5e-e923-4d44-bcbf-6956d2436ef2@googlegroups.com>,
> Alla <modelling.data@gmail.com> wrote:
> 
>>                $new_entry = fgetcsv($open_file, 0, "\t");
> 
> Why are you not checking that fgetcsv didn't return a boolean?
> 
> I could also ask why your program is such a convoluted if/then/else
> mess but I can't be bothered.

Alla is learning.  No one is born a master. :-)

-- 
Christoph M. Becker

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#16959 — Re: PHP Warning: extract() expects parameter 1 to be array

Christoph,

> Alla is learning.  No one is born a master. :-)

True that.   And if we're lucky we will be novices many times again before
we EOL.

I have to say that Tim made a good first remark.  Its always good to check
the result of whatever you call if it doen't work as expected.

A shame that he followed that up with a put-down though.  It seems he has
forgotten his own novice days.

But he just kills any positive vibe by that "can't be bothered" there. :-(

Regards,
Rudy Wieser


Christoph M. Becker <cmbecker69@arcor.de> schreef in berichtnieuws
npa6ob$q4u$1@solani.org...
> On 20.08.2016 at 19:21, Tim Streater wrote:
>
> > In article <2d416b5e-e923-4d44-bcbf-6956d2436ef2@googlegroups.com>,
> > Alla <modelling.data@gmail.com> wrote:
> >
> >>                $new_entry = fgetcsv($open_file, 0, "\t");
> >
> > Why are you not checking that fgetcsv didn't return a boolean?
> >
> > I could also ask why your program is such a convoluted if/then/else
> > mess but I can't be bothered.
>
> Alla is learning.  No one is born a master. :-)
>
> --
> Christoph M. Becker
>

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#16960 — Re: PHP Warning: extract() expects parameter 1 to be array

In article <57b8ae49$0$799$e4fe514c@news.xs4all.nl>, R.Wieser
<address@not.available> wrote:

>Christoph,
>
>> Alla is learning.  No one is born a master. :-)
>
>True that.   And if we're lucky we will be novices many times again before
>we EOL.
>
>I have to say that Tim made a good first remark.  Its always good to check
>the result of whatever you call if it doen't work as expected.

Always fully check the doc regarding any function used. The nice thing
about PHP is that the online documentation is very good.

>A shame that he followed that up with a put-down though.  It seems he has
>forgotten his own novice days.

I'm feeling very languid these days. It is now 50 years since I broke
my first computer.

>But he just kills any positive vibe by that "can't be bothered" there. :-(

But I am learning Xojo and being a novice again.

>Christoph M. Becker <cmbecker69@arcor.de> schreef in berichtnieuws
>npa6ob$q4u$1@solani.org...
>> On 20.08.2016 at 19:21, Tim Streater wrote:
>>
>> > In article <2d416b5e-e923-4d44-bcbf-6956d2436ef2@googlegroups.com>,
>> > Alla <modelling.data@gmail.com> wrote:
>> >
>> >>                $new_entry = fgetcsv($open_file, 0, "\t");
>> >
>> > Why are you not checking that fgetcsv didn't return a boolean?
>> >
>> > I could also ask why your program is such a convoluted if/then/else
>> > mess but I can't be bothered.
>>
>> Alla is learning.  No one is born a master. :-)
>>
>> --
>> Christoph M. Becker
>>
>
>

-- 
Lady Astor: "If you were my husband I'd give you poison." Churchill: "If
you were my wife, I'd drink it."

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#16961 — Re: PHP Warning: extract() expects parameter 1 to be array

On Saturday, August 20, 2016 at 9:15:44 PM UTC+3, Christoph M. Becker wrote:
> On 20.08.2016 at 19:21, Tim Streater wrote:
> 
> > In article <2d416b5e-e923-4d44-bcbf-6956d2436ef2@googlegroups.com>,
> > Alla <modelling.data@gmail.com> wrote:
> > 
> >>                $new_entry = fgetcsv($open_file, 0, "\t");
> > 
> > Why are you not checking that fgetcsv didn't return a boolean?
> > 
> > I could also ask why your program is such a convoluted if/then/else
> > mess but I can't be bothered.
> 
> Alla is learning.  No one is born a master. :-)
> 
> -- 
> Christoph M. Becker

Christoph and Rudy, Thank you very much!
As to Tim's message, which I can see only as a quotation here, I am fine with 
all criticism, even harsh one, but if it contains correct remarks, as Tim's message 
does, - it is also very helpful in learning. And I do agree
about the "convoluted mess"; I am struggling with this issue,
including in my C coding experience. I am in the processes, hopefully a successful
one eventually :)

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#16962 — Re: PHP Warning: extract() expects parameter 1 to be array

In article <18d88f90-6b3b-4e2f-8b9f-5cb9c69176a1@googlegroups.com>,
Alla <modelling.data@gmail.com> wrote:

>On Saturday, August 20, 2016 at 9:15:44 PM UTC+3, Christoph M. Becker wrote:
>> On 20.08.2016 at 19:21, Tim Streater wrote:
>> 
>> > In article <2d416b5e-e923-4d44-bcbf-6956d2436ef2@googlegroups.com>,
>> > Alla <modelling.data@gmail.com> wrote:
>> > 
>> >>                $new_entry = fgetcsv($open_file, 0, "\t");
>> > 
>> > Why are you not checking that fgetcsv didn't return a boolean?
>> > 
>> > I could also ask why your program is such a convoluted if/then/else
>> > mess but I can't be bothered.
>> 
>> Alla is learning.  No one is born a master. :-)

>Christoph and Rudy, Thank you very much!
>As to Tim's message, which I can see only as a quotation here, I am fine with 
>all criticism, even harsh one, but if it contains correct remarks, as Tim's
>message 
>does, - it is also very helpful in learning. And I do agree
>about the "convoluted mess"; I am struggling with this issue,
>including in my C coding experience. I am in the processes, hopefully a successful
>one eventually :)

There was a time around 1980 when computer science students were
apparently being told that single-entry-single-exit was the way to
write functions and procedures. This approach was assisted by the fact
that Pascal didn't even have a return statement.

I've always found this approach to be foolish as it increases
complexity for no benefit, and on the one occasion when I was forced to
write a substantial piece of code in Pascal, I used to systematically
put a 999: label at the end of the function, to which I could GOTO when
needed.

In my view, you should be doing thus:

// Start with all tests for conditions that prevent the program being
run

if  ($argc<2)
     {
     echo "Please, provide a path to a file\n";
     exit ()
     }

if  (!file_exists($file))
     {
     echo "Sorry, there is no such file $file\n";
     exit ()
     }

if  (!is_readable($file))
     {
     echo "$file is not readable\n";
     exit ()
     }

// other tests etc, then finally:

$open_file = fopen($file, "r");
if  ($open_file===false)
     {
     echo "Sorry, couldn't open $file\n";
     exit ();
     }

// Now comes the real meat of the program

while (...)
     {

     // Main work is here

     }


This sort of approach is, IMO, much more readable. Get the error
checking out of the way first. Then you can concentrate on what it is
you really want to do with the program without having to worry whether
your if/then/else nesting is correct - because there isn't any!

Now I'm off to a family picnic at Polesden Lacey.

-- 
"... you must remember that if you're trying to propagate a creed of 
 poverty, gentleness and tolerance,  you need a very rich, powerful,
 authoritarian organisation to do it."             - Vice-Pope Eric

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#16963 — Re: PHP Warning: extract() expects parameter 1 to be array

On 8/21/2016 5:26 AM, Tim Streater wrote:
> In article <18d88f90-6b3b-4e2f-8b9f-5cb9c69176a1@googlegroups.com>,
> Alla <modelling.data@gmail.com> wrote:
> 
>> On Saturday, August 20, 2016 at 9:15:44 PM UTC+3, Christoph M. Becker
>> wrote:
>>> On 20.08.2016 at 19:21, Tim Streater wrote:
>>>
>>> > In article <2d416b5e-e923-4d44-bcbf-6956d2436ef2@googlegroups.com>,
>>> > Alla <modelling.data@gmail.com> wrote:
>>> > >>                $new_entry = fgetcsv($open_file, 0, "\t");
>>> > > Why are you not checking that fgetcsv didn't return a boolean?
>>> > > I could also ask why your program is such a convoluted if/then/else
>>> > mess but I can't be bothered.
>>>
>>> Alla is learning.  No one is born a master. :-)
> 
>> Christoph and Rudy, Thank you very much!
>> As to Tim's message, which I can see only as a quotation here, I am
>> fine with all criticism, even harsh one, but if it contains correct
>> remarks, as Tim's
>> message does, - it is also very helpful in learning. And I do agree
>> about the "convoluted mess"; I am struggling with this issue,
>> including in my C coding experience. I am in the processes, hopefully
>> a successful
>> one eventually :)
> 
> There was a time around 1980 when computer science students were
> apparently being told that single-entry-single-exit was the way to
> write functions and procedures. This approach was assisted by the fact
> that Pascal didn't even have a return statement.
> 
> I've always found this approach to be foolish as it increases
> complexity for no benefit, and on the one occasion when I was forced to
> write a substantial piece of code in Pascal, I used to systematically
> put a 999: label at the end of the function, to which I could GOTO when
> needed.
> 

Tim,

It's still be espounded by some C programmers, but none I have seen that
I would consider competent (from other things they also say).

-- 
==================
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Jerry Stuckle
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==================

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#16967 — Re: PHP Warning: extract() expects parameter 1 to be array

Tim Streater <timstreater@greenbee.net> writes:

> In article <18d88f90-6b3b-4e2f-8b9f-5cb9c69176a1@googlegroups.com>,
> Alla <modelling.data@gmail.com> wrote:
>
>>On Saturday, August 20, 2016 at 9:15:44 PM UTC+3, Christoph M. Becker wrote:
>>> On 20.08.2016 at 19:21, Tim Streater wrote:
>>>
>>> > In article <2d416b5e-e923-4d44-bcbf-6956d2436ef2@googlegroups.com>,
>>> > Alla <modelling.data@gmail.com> wrote:
>>> > >>                $new_entry = fgetcsv($open_file, 0, "\t");
>>> > > Why are you not checking that fgetcsv didn't return a boolean?
>>> > > I could also ask why your program is such a convoluted
>>> if/then/else
>>> > mess but I can't be bothered.
>>>
>>> Alla is learning.  No one is born a master. :-)
>
>>Christoph and Rudy, Thank you very much!
>> As to Tim's message, which I can see only as a quotation here, I am
>> fine with all criticism, even harsh one, but if it contains correct
>> remarks, as Tim's
>> message does, - it is also very helpful in learning. And I do agree
>>about the "convoluted mess"; I am struggling with this issue,
>>including in my C coding experience. I am in the processes, hopefully
>> a successful
>>one eventually :)
>
> There was a time around 1980 when computer science students were
> apparently being told that single-entry-single-exit was the way to
> write functions and procedures. This approach was assisted by the fact
> that Pascal didn't even have a return statement.
>
> I've always found this approach to be foolish as it increases
> complexity for no benefit,

No benefit (in all cases) is a little strong.  In some situation it can
be useful.  For example when you have very limited debug facilities
being able to add print or logging call in one place can be helpful.
The problem comes from it being made a rule, with no thought put into
what the costs might be compared to any benefits.

<snip>
> In my view, you should be doing thus:
>
> // Start with all tests for conditions that prevent the program being
> run
>
> if  ($argc<2)
>     {
>     echo "Please, provide a path to a file\n";
>     exit ()
>     }
>
> if  (!file_exists($file))
>     {
>     echo "Sorry, there is no such file $file\n";
>     exit ()
>     }
>
> if  (!is_readable($file))
>     {
>     echo "$file is not readable\n";
>     exit ()
>     }
>
> // other tests etc, then finally:
>
> $open_file = fopen($file, "r");
> if  ($open_file===false)
>     {
>     echo "Sorry, couldn't open $file\n";
>     exit ();
>     }
>
> // Now comes the real meat of the program
>
> while (...)
>     {
>
>     // Main work is here
>
>     }

Generally a good plan, but in this case I prefer the "more structured"
version:

if ($argc < 2)
    echo "Please, provide a path to a file\n";
else if (!file_exists($file))
    echo "Sorry, there is no such file $file\n";
else if (!is_readable($file))
    echo "$file is not readable\n";
...
else if (($open_file = fopen($file, "r")) === false)
    echo "Sorry, couldn't open $file\n";
else {
    // All ok.  Let's get on with it...

    while (...)
    {
    // Main work is here
    }
}

Obviously put the {} back if your style rules require them.

(You probably did this only for the purposes example, but since many
people might see this, I'd point out that it's usually better just to
try to open a file.  Testing for specific problem before hand is going
to work 99.9999% of the time, but it introduces a race condition that
is, to my mind, inelegant.)

<snip>
-- 
Ben.

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#16971 — Re: PHP Warning: extract() expects parameter 1 to be array

Ben Bacarisse wrote:

> […] I prefer the "more structured" version:
> 
> if ($argc < 2)
>     echo "Please, provide a path to a file\n";
> else if (!file_exists($file))
>     echo "Sorry, there is no such file $file\n";
> else if (!is_readable($file))
>     echo "$file is not readable\n";
> ...
> else if (($open_file = fopen($file, "r")) === false)
>     echo "Sorry, couldn't open $file\n";
> else {
>     // All ok.  Let's get on with it...
> 
>     while (...)
>     {
>     // Main work is here
>     }
> }

This code style is a maintenance nightmare (the missing blocks and the 
assignment in the “if” statement doubly so).  Do you know what the condition 
on line 50 was because of which you wrote “else” on line 100?

Also, PHP is influenced by C, but it is _not_ C.  The function should throw 
(PHP Standard Library) exceptions like \InvalidArgumentException instead of 
echo-ing error conditions without regard to the user’s locale.  This will 
also get them a stack trace (even better if the Xdebug extension is 
installed and enabled) if they do not catch the exception.  As a result, the 
then-unnecessary “else” statements would vanish in a puff of program logic.

<http://php.net/manual/en/language.exceptions.php>

-- 
PointedEars
Zend Certified PHP Engineer 
<http://www.zend.com/en/yellow-pages/ZEND024953> | Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.

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#16973 — Re: PHP Warning: extract() expects parameter 1 to be array

On 8/22/2016 3:34 PM, the troll Thomas 'Pointed Head' Lahn wrote:
> Ben Bacarisse wrote:
> 
>> […] I prefer the "more structured" version:
>>
>> if ($argc < 2)
>>     echo "Please, provide a path to a file\n";
>> else if (!file_exists($file))
>>     echo "Sorry, there is no such file $file\n";
>> else if (!is_readable($file))
>>     echo "$file is not readable\n";
>> ...
>> else if (($open_file = fopen($file, "r")) === false)
>>     echo "Sorry, couldn't open $file\n";
>> else {
>>     // All ok.  Let's get on with it...
>>
>>     while (...)
>>     {
>>     // Main work is here
>>     }
>> }
> 
> This code style is a maintenance nightmare (the missing blocks and the 
> assignment in the “if” statement doubly so).  Do you know what the condition 
> on line 50 was because of which you wrote “else” on line 100?
>

Yes - if the code is properly indented and commented (something you
wouldn't understand).

> Also, PHP is influenced by C, but it is _not_ C.  The function should throw 
> (PHP Standard Library) exceptions like \InvalidArgumentException instead of 
> echo-ing error conditions without regard to the user’s locale.  This will 
> also get them a stack trace (even better if the Xdebug extension is 
> installed and enabled) if they do not catch the exception.  As a result, the 
> then-unnecessary “else” statements would vanish in a puff of program logic.
> 

Which would display to a user internal details of your code - a huge
security exposure.  But you don't understand security, either, do you?

In addition, it will immediately stop processing of the page - resulting
in invalid HTML being sent to the browser.  Something else you don't
care about, either.

> <http://php.net/manual/en/language.exceptions.php>
> 

Glad you can cut/paste a URL.  Too bad you don't understand how write
good PHP code.

-- 
==================
Remove the "x" from my email address
Jerry Stuckle
jstucklex@attglobal.net
==================

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#16975 — Re: PHP Warning: extract() expects parameter 1 to be array

Jerry Stuckle <jstucklex@attglobal.net> writes:

> On 8/22/2016 3:34 PM, the troll Thomas 'Pointed Head' Lahn wrote:
>> Ben Bacarisse wrote:
>> 
>>> […] I prefer the "more structured" version:
>>>
>>> if ($argc < 2)
>>>     echo "Please, provide a path to a file\n";
>>> else if (!file_exists($file))
>>>     echo "Sorry, there is no such file $file\n";
>>> else if (!is_readable($file))
>>>     echo "$file is not readable\n";
>>> ...
>>> else if (($open_file = fopen($file, "r")) === false)
>>>     echo "Sorry, couldn't open $file\n";
>>> else {
>>>     // All ok.  Let's get on with it...
>>>
>>>     while (...)
>>>     {
>>>     // Main work is here
>>>     }
>>> }
>> 
>> This code style is a maintenance nightmare (the missing blocks and the 
>> assignment in the “if” statement doubly so).  Do you know what the condition 
>> on line 50 was because of which you wrote “else” on line 100?
>>
>
> Yes - if the code is properly indented and commented (something you
> wouldn't understand).
>
>> Also, PHP is influenced by C, but it is _not_ C.  The function should throw 
>> (PHP Standard Library) exceptions like \InvalidArgumentException instead of 
>> echo-ing error conditions without regard to the user’s locale.  This will 
>> also get them a stack trace (even better if the Xdebug extension is 
>> installed and enabled) if they do not catch the exception.  As a result, the 
>> then-unnecessary “else” statements would vanish in a puff of program logic.
>> 
>
> Which would display to a user internal details of your code - a huge
> security exposure.  But you don't understand security, either, do you?
>
> In addition, it will immediately stop processing of the page - resulting
> in invalid HTML being sent to the browser.  Something else you don't
> care about, either.
>
>> <http://php.net/manual/en/language.exceptions.php>
>> 
>
> Glad you can cut/paste a URL.  Too bad you don't understand how write
> good PHP code.

Details of stack traces are only exposed if the environment
(production?) is configured to match that of a developer environment
(such as showing errors vs logging them).

It is also quite easy to wrap your outer-most layer of code input/output
in a try/catch block and handle:

- Rendering a generic or descriptive error message for the user in the
  catch block

- Manually logging the stack trace (part of the \Exception object) to a
  file or sending as part of an email to the webmaster (if this is not
  configurable in the php.ini of the server for some reason)

- Ensuring the HTML the user receives is still valid

This also allows for easier to extend code in the future, as you end up
with a single exit point.

-- 
Matthew Carter (m@ahungry.com)
http://ahungry.com

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#16977 — Re: PHP Warning: extract() expects parameter 1 to be array

On 8/23/2016 1:26 AM, Matthew Carter wrote:
> Jerry Stuckle <jstucklex@attglobal.net> writes:
> 
>> On 8/22/2016 3:34 PM, the troll Thomas 'Pointed Head' Lahn wrote:
>>> Ben Bacarisse wrote:
>>>
>>>> […] I prefer the "more structured" version:
>>>>
>>>> if ($argc < 2)
>>>>     echo "Please, provide a path to a file\n";
>>>> else if (!file_exists($file))
>>>>     echo "Sorry, there is no such file $file\n";
>>>> else if (!is_readable($file))
>>>>     echo "$file is not readable\n";
>>>> ...
>>>> else if (($open_file = fopen($file, "r")) === false)
>>>>     echo "Sorry, couldn't open $file\n";
>>>> else {
>>>>     // All ok.  Let's get on with it...
>>>>
>>>>     while (...)
>>>>     {
>>>>     // Main work is here
>>>>     }
>>>> }
>>>
>>> This code style is a maintenance nightmare (the missing blocks and the 
>>> assignment in the “if” statement doubly so).  Do you know what the condition 
>>> on line 50 was because of which you wrote “else” on line 100?
>>>
>>
>> Yes - if the code is properly indented and commented (something you
>> wouldn't understand).
>>
>>> Also, PHP is influenced by C, but it is _not_ C.  The function should throw 
>>> (PHP Standard Library) exceptions like \InvalidArgumentException instead of 
>>> echo-ing error conditions without regard to the user’s locale.  This will 
>>> also get them a stack trace (even better if the Xdebug extension is 
>>> installed and enabled) if they do not catch the exception.  As a result, the 
>>> then-unnecessary “else” statements would vanish in a puff of program logic.
>>>
>>
>> Which would display to a user internal details of your code - a huge
>> security exposure.  But you don't understand security, either, do you?
>>
>> In addition, it will immediately stop processing of the page - resulting
>> in invalid HTML being sent to the browser.  Something else you don't
>> care about, either.
>>
>>> <http://php.net/manual/en/language.exceptions.php>
>>>
>>
>> Glad you can cut/paste a URL.  Too bad you don't understand how write
>> good PHP code.
> 
> Details of stack traces are only exposed if the environment
> (production?) is configured to match that of a developer environment
> (such as showing errors vs logging them).
> 
> It is also quite easy to wrap your outer-most layer of code input/output
> in a try/catch block and handle:
> 
> - Rendering a generic or descriptive error message for the user in the
>   catch block
> 
> - Manually logging the stack trace (part of the \Exception object) to a
>   file or sending as part of an email to the webmaster (if this is not
>   configurable in the php.ini of the server for some reason)
> 
> - Ensuring the HTML the user receives is still valid
> 
> This also allows for easier to extend code in the future, as you end up
> with a single exit point.
> 

You obviously didn't read Pointed Head's post, did you?

-- 
==================
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jstucklex@attglobal.net
==================

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