For a programming exercise, I am mean to design a Perl script that detects double letters in a text file.
I tried the following expressions
# Check for any double letter within the alphabet
/+/
# Check for any repetition of an alphanumeric character
/\w+/
Im aware that the... (8 Replies)
Hi,
Can anyone help me to find regular expression for the following in Perl?
"The string can only contain lower case letters (a-z) and no more than one of any letter."
For example: "table" is accepted, whether "dude" is not.
I have coded like this:
$str = "table";
if ($str =~ m/\b()\b/) {... (4 Replies)
I have got numbers like
l255677
l376039
l188144
l340482
l440700
l254113
to match the numbers starting with '13' what would be the regex
=~/13(.*)/ =======>This is not working ....
But for user123,user657
regex =~/user(.*)/ ========>works
Thanks for help..!! (7 Replies)
I am having trouble parsing rpm filenames in a shell script.. I found a snippet of perl code that will perform the task but I really don't have time to rewrite the entire script in perl. I cannot for the life of me convert this code into something sed-friendly:
if ($rpm =~ /(*)-(*)-(*)\.(.*)/)... (1 Reply)
Hi,
I get the following when I cat a file *.log
xxxxx
=====
dasdas gwdgsg fdsagfsag agsdfag
=====
random data
=====
My output should look like :
If the random data after the 2nd ==== is null then OK should be printed else
the random data should be printed.
How do I go about this... (5 Replies)
Hi Guys
I have the following regex
$OSRELEASE = $1 if ($output =~ /(Mac OS X (Server )?10.\d)/);
output is currently
Mac OS X 10.7.5
when the introduction of Mac 10.8 output changes to
OS X 10.8.2
they have dropped the Mac bit so i changed the regex to be (2 Replies)
Hello,
I'm trying to get a quick help on regex since i'm not a regular programmer.
Below is the line i'm trying to apply my regex to..i want to use the regex in a for loop and this line will keep on changing.
subject=... (4 Replies)
Could anyone please make me understand how the ?= works below ..
After executing this I am getting the same output.
$string="I love chocolate.";
$string =~ s/chocolate(?= ice)/vanilla/;
print "$string\n"; (2 Replies)
I am not a big expert in regex and have just little understanding of that language.
Could you help me to understand the regular Perl expression:
^(?!if\b|else\b|while\b|)(?:+?\s+){1,6}(+\s*)\(*\) *?(?:^*;?+){0,10}\{
------
This is regex to select functions from a C/C++ source and defined in... (2 Replies)
Experts -
I found a script on one of the servers that I work on and I need help understanding
one of the lines.
I know what the script does, but I'm having a hard time understanding the grouping.
Can someone help me with this?
Here's the script...
#!/usr/bin/perl
use strict;
use... (2 Replies)
Discussion started by: timj123
2 Replies
LEARN ABOUT PHP
debug_zval_dump
DEBUG_ZVAL_DUMP(3) 1 DEBUG_ZVAL_DUMP(3)debug_zval_dump - Dumps a string representation of an internal zend value to outputSYNOPSIS
void debug_zval_dump (mixed $variable, [mixed $...])
DESCRIPTION
Dumps a string representation of an internal zend value to output.
PARAMETERS
o $variable
- The variable being evaluated.
RETURN VALUES
No value is returned.
EXAMPLES
Example #1
debug_zval_dump(3) example
<?php
$var1 = 'Hello World';
$var2 = '';
$var2 =& $var1;
debug_zval_dump(&$var1);
?>
The above example will output:
&string(11) "Hello World" refcount(3)
Note
Beware the refcount
The refcount value returned by this function is non-obvious in certain circumstances. For example, a developer might expect the
above example to indicate a refcount of 2. The third reference is created when actually calling debug_zval_dump(3).
This behavior is further compounded when a variable is not passed to debug_zval_dump(3) by reference. To illustrate, consider a
slightly modified version of the above example:
Example #2
<?php
$var1 = 'Hello World';
$var2 = '';
$var2 =& $var1;
debug_zval_dump($var1); // not passed by reference, this time
?>
The above example will output:
string(11) "Hello World" refcount(1)
Why refcount(1)? Because a copy of $var1 is being made, when the function is called.
This function becomes even more confusing when a variable with a refcount of 1 is passed (by copy/value):
Example #3
<?php
$var1 = 'Hello World';
debug_zval_dump($var1);
?>
The above example will output:
string(11) "Hello World" refcount(2)
A refcount of 2, here, is extremely non-obvious. Especially considering the above examples. So what's happening?
When a variable has a single reference (as did $var1 before it was used as an argument to debug_zval_dump(3)), PHP's engine opti-
mizes the manner in which it is passed to a function. Internally, PHP treats $var1 like a reference (in that the refcount is
increased for the scope of this function), with the caveat that if the passed reference happens to be written to, a copy is made,
but only at the moment of writing. This is known as "copy on write."
So, if debug_zval_dump(3) happened to write to its sole parameter (and it doesn't), then a copy would be made. Until then, the
parameter remains a reference, causing the refcount to be incremented to 2 for the scope of the function call.
SEE ALSO var_dump(3), debug_backtrace(3), References Explained, References Explained (by Derick Rethans).
PHP Documentation Group DEBUG_ZVAL_DUMP(3)