Storing "\t" in strings?

[sprocket]

Hi folks,

I need to store delimiter values in mysql, but I can't get PHP to interpret them when backslashes are involved, eg the tab delimiter (backlash-t)

As an example:

$delimiter = $_data['_delimiter'];
echo"Delimitor is <".$delimiter."> it should be <\t>";

Prints out:

Delimitor is <\t> it should be <	>

Why is PHP treating the value of the string literally rather than interpreting it for what it is?

[AIS4U]

sprocket:

Possibly because you have used double quotes (").

Try using single quote (').

[Plasma]

You will need to place quotes around your variable name in order for PHP to parse it (otherwise, it just gives the string value - which is '\t'):

echo"Delimitor is <$delimiter> it should be <\t>"; 

Will produce:

Delimitor is <	        > it should be <	        >

[samudasu]

Read the section on strings in the PHP Maunual. The manual is your friend. Use it!

http://de.php.net/manual/en/language.types.string.php

[sprocket]

samudasu wrote:

Read the section on strings in the PHP Maunual. The manual is your friend. Use it!

http://de.php.net/manual/en/language.types.string.php

yes, yes, I know about double quotes and single quotes and really saying "The manual is your friend. Use it!" is not very helpful. In fact 100% of all questions regarding "Coding help" could be answered with your response.

Now, back to my problem. I cannot put my particular variable in double quotes, since it is an associative array and as such needs to go outside the double quotes....

$delimiter = "\t";
echo"Delimitor is <$delimiter> it should be <\t>";

Will work nicely.
But,

$delimiter = $reseller_data['feed_delimiter'];
echo"Delimitor is <$delimiter> it should be <\t>";

will not. So how do I get $reseller_data['feed_delimiter'] inside double quotes?

[Plasma]

Why do associative arrays need to go outside double quotes? Your not making much sense.

$delimiter = $reseller_data['feed_delimiter'];

What value are you expecting $delimiter to now hold? An array, or an actual value like a "tab" character?

[sprocket]

not even

$delimiter = "$reseller_data[feed_delimiter]";

works - this is driving me nuts!

[sprocket]

Plasma wrote:

Why do associative arrays need to go outside double quotes? Your not making much sense.

$delimiter = $reseller_data['feed_delimiter'];

What value are you expecting $delimiter to now hold? An array, or an actual value like a "tab" character?

I have a (bad?) habit of using single quotes in my associative arrays, and as such, they need to go outside of the double quotes or an error is given.

anyway
echo"Delimitor is <$reseller_data[feed_delimiter]> it should be <\t>";
gives as always the same response

Delimitor is <\t> it should be <	>

In mysql the value "\t" is stored in the field "feed_delimiter" and hence I expect the value of $reseller_data['feed_delimiter'] to be the [tab]

[sprocket]

Sorry Samudasu, but if you can find easily in the PHP manual the paragraph that explains this oddity, then I'll let your flying comment go. If not, please take the time to understand someones problem before throwing the manual at them.

OK.
Code1:

echo"Delimitor is <$reseller_data[feed_delimiter]> it should be <\t>";

outputs:

Delimitor is <\t> it should be <	>

Yet Code 2:

if( $reseller_data['feed_delimiter'] == '\t') $delimiter = "\t";
print("Delimiter is <$delimiter> it should be <\t>");

Outputs:

Delimiter is <	> it should be <	>

Whyso?

[Plasma]

Did you read Post #3 above which was by me?

It does exactally what you want.

 $delimiter = $reseller_data['feed_delimiter'];
echo"Delimitor is <$delimiter> it should be <\t>";

Whats wrong with this? This WILL output it with a tab in both places - I dont get what the problem is.

You can even write it like this, to remove the need for another variable:

echo "Delimitor is <{$reseller_data['feed_delimiter']}> it should be <\t>";

[Installer]

With your code:

$reseller_data['feed_delimiter'] = "\t";

if( $reseller_data['feed_delimiter'] == '\t') $delimiter = "\t"; 
print("Delimiter is <$delimiter> it should be <\t>"); 
exit;

I get this

Notice: Undefined variable: delimiter in C:\htdocs\test\index.php on line 5
Delimiter is <> it should be < >

A re-read of this manual page will help you understand why (it has to do with single quotes and backslashes).

[sprocket]

Plasma wrote:

Did you read Post #3 above which was by me?

It does exactally what you want.

 $delimiter = $reseller_data['feed_delimiter'];
echo"Delimitor is <$delimiter> it should be <\t>";

Whats wrong with this? This WILL output it with a tab in both places - I dont get what the problem is.

You can even write it like this, to remove the need for another variable:

echo "Delimitor is <{$reseller_data['feed_delimiter']}> it should be <\t>";

Sorry not to reply directly to you Plasma, but your example doesn't work for my MySQL-generated \t
The same goes for Installer's example.

I entered \t into the database via PHPmyadmin and it shows as \t. There are no magic_quotes_gpc enabled or anything, so slashes are not getting added or anything like that. I guess the problem comes in the way that mysql has stored the \t as a literal \t (ie \t). I don't know or understand.

[sprocket]

just to show that \t is not stored in some bizarre manner in mysql, at the command line:

mysql> select feed_delimiter from feeds where id=1;
+----------------+
| feed_delimiter |
+----------------+
| \t             |
+----------------+
1 row in set (0.00 sec)

[Plasma]

Try:

$delimiter = str_replace('\t', "\t", $reseller_data['feed_delimiter']);
echo"Delimitor is <$delimiter> it should be <\t>";

Will replace literal \t with a tab character if found in the feed string.

[sprocket]

Installer wrote:

With your code:

$reseller_data['feed_delimiter'] = "\t";

Ah, but no. I can't get my mysql_fetch_array() to do that - my actual code:

while ($reseller_data = mysql_fetch_array($feedQ, MYSQL_ASSOC)) {
   $delimiter = $reseller_data['feed_delimiter']; 
   echo"Delimiter is <$delimiter> it should be <\t>";
}

but what that is effectively doing is

$delimiter = '\t';

which is no good

[sprocket]

Plasma wrote:

Try:

$delimiter = str_replace('\t', "\t", $reseller_data['feed_delimiter']);
echo"Delimitor is <$delimiter> it should be <\t>";

Will replace literal \t with a tab character if found in the feed string.

Yes, that works, but it is a variation on the solution I found in post #9:

if( $reseller_data['feed_delimiter'] == '\t') $delimiter = "\t";

But, yes I agree with you - \t has been put into the array by mysql_fetch_assoc as a literal \t

[sprocket]

And... I found out why - phpMyAdmin was escaping the backslash for mysql entry

UPDATE `feeds` SET `feed_delimiter` = '\\t' WHERE `id` =1;

But if the following is executed:

UPDATE `feeds` SET `feed_delimiter` = '\t' WHERE `id` =1;

OR in mysql config sql_mode is set to 'NO_BACKSLASH_ESCAPES'

then all is well.

So in fact it was a mysql "problem"
Cheers

[cbj4074]

Do us a favor and mark this thread resolved, please.