substr/ereg question

[MIchel]

Hi Group,

I want to reprint a part of a form if the length of the input is higher than
a predetermed length.
For instance, if someone posts a name, longer than 15 characters, I want to
cut it back to 15 characters and ask for confirmation on a control sheet.

I already slapped myself for doing this:

if($name=substr($name,0,15)){//take action//}

I thought this would only be true is the string itself was actually cut...
big bullpoop it is of course :(
Now... I think it's pretty much clear what I want.

a: cut string IF longer than 15 chars.
b: set flag IF string's been cut.

Is there someone who knows a regexp maybe that does this and who's willing
to share and save me some time?

Thanks,

Michel

[J.O. Aho]

MIchel wrote:

I already slapped myself for doing this:

if($name=substr($name,0,15)){//take action//}

I thought this would only be true is the string itself was actually cut...
big bullpoop it is of course :(
Now... I think it's pretty much clear what I want.
When assigning a value to a variable, will always be true, so what you are
doing is cutting down the string to mac 15 characters.
a: cut string IF longer than 15 chars.
if( strlen($name)>15 ) {
b: set flag IF string's been cut.

$shortname=substr($name,0,15);

}

you can test the flag with

if(isset($shortname) {
/* do what ever you want */
}
//Aho

[MIchel]

if( strlen($name)>15 ) {

b: set flag IF string's been cut.

$shortname=substr($name,0,15);

}

you can test the flag with

if(isset($shortname) {
/* do what ever you want */
}

Hi J.O.,

Yeah. I can do it like that, but it's not quite what I had in mind... there
has to be a way to do this in a oneliner. something like:

$result=(cutthisstringiflongerthan15) that both does the cutting and sets
$result to TRUE.

I was thinking some regexp.

No?

[J.O. Aho]

MIchel wrote:

if( strlen($name)>15 ) {

b: set flag IF string's been cut.

$shortname=substr($name,0,15);

}

you can test the flag with

if(isset($shortname) {
/* do what ever you want */
}

Hi J.O.,

Yeah. I can do it like that, but it's not quite what I had in mind... there
has to be a way to do this in a oneliner. something like:

$result=(cutthisstringiflongerthan15) that both does the cutting and sets
$result to TRUE.

I was thinking some regexp.

No?

don't think so, I fear you would get a true in each case.
//Aho

[Janwillem Borleffs]

MIchel wrote:

Yeah. I can do it like that, but it's not quite what I had in mind...
there has to be a way to do this in a oneliner. something like:

$result=(cutthisstringiflongerthan15) that both does the cutting and
sets $result to TRUE.

For this, you will need to write a function that takes a string as an
argument by reference, cuts it and returns the remaining piece or nothing
when the string isn't longer than the defined length, which equals to false.

Example:

function cut_string(&$string, $length) {
if (preg_match("/^(.{".$length."})(.*)$/", $string, $matches)) {
list(,$string,$result) = $matches;
return $result;
}
}

$mystring = "astringthatismuchlongerthan15chars";
if ($result = cut_string($mystring, 15)) {
// $mystring exceeds 15 characters in length
}
JW

[Janwillem Borleffs]

Janwillem Borleffs wrote:

For this, you will need to write a function that takes a string as an
argument by reference, cuts it and returns the remaining piece or
nothing when the string isn't longer than the defined length, which
equals to false.

Nah, can be done without the custom function:

$mystring = "astringthatismuchlongerthan15chars";
list($mystring, $result) = preg_split("/(?<=.{15})/", $mystring);

if ($result) {
// $mystring exceeds 15 characters in length
}
JW

[Janwillem Borleffs]

Janwillem Borleffs wrote:

list($mystring, $result) = preg_split("/(?<=.{15})/", $mystring);

The above will throw a warning when $mystring contains less then 15
characters. This can be fixed as follows:

list($mystring, $result) = preg_split("/(?<=.{15})|$/", $mystring);
JW

[Michel]

Thank you all very much for your suggestions. I have a working solution now.

Michel

"Janwillem Borleffs" <[e-mail]> wrote in message
news:42***********************@news.euronet.nl...

Janwillem Borleffs wrote:

list($mystring, $result) = preg_split("/(?<=.{15})/", $mystring);

The above will throw a warning when $mystring contains less then 15
characters. This can be fixed as follows:

list($mystring, $result) = preg_split("/(?<=.{15})|$/", $mystring);
JW

[Jerry Sievers]

"MIchel" <[e-mail]> writes:

Yeah. I can do it like that, but it's not quite what I had in mind... there
has to be a way to do this in a oneliner. something like:

Right. There HAS to be a way and someone did eventually post one or
more examples.

Why so hell bent on a one liner? I think you will learn from
experience that these one-liners are often terse and unreadable and
merit at least a one-liner comment along with them (we are speaking
about mature, production quality code now).

if(strlen)$input_string) > 15)
{
cut string;
do something special
}

Easy to write, easy to read, self-documenting.

But you wanted a one-liner. Well, here's a tru one-liner using no
regexp and with the test also on the same line.

$string = 'well, hello there !!!';
$length = 15;

if($string !== ($string = substr($string, 0, $length)))
print $string;

YMMV

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305 321-1144 (mobile http://www.JerrySievers.com/

[Evert]

MIchel wrote:

a: cut string IF longer than 15 chars.
b: set flag IF string's been cut.

What about:

$shortname = strlen($name)>15?substr($name,0,15):false;

grt,
Evert
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