When the compiler sees this, it sees " Hello "World"" as three things - a string " Hello ", the token World and an empty string, "". To get it to recognise the middle quotes as part of the string, as opposed to the end/start of the string, you need to escape them with the \ character (just like you use \n and the compiler recognizes you mean a newline, not the letter 'n'):
This User Gave Thanks to JohnGraham For This Post:
I'm not very familiar with the ssh command. When I tried to set a variable and then echo its value on a remote machine via ssh, I found a problem. For example,
$ ITSME=itsme
$ ssh xxx.xxxx.xxx.xxx "ITSME=itsyou; echo $ITSME"
itsme
$ ssh xxx.xxxx.xxx.xxx 'ITSME=itsyou; echo $ITSME'
itsyou
$... (3 Replies)
Hi guys, I have a sed line in double quotes which works fine, but I want it to be in single quotes
here is the sed line
sed "/abc_def/s/\'.*\'/\'\${abc_def}\'/"
can some one give the equivalent to the above script in single quotes
Thanks a ton (5 Replies)
Unix superusers,
I am new to unix but would like to learn more about grep. I am very familiar with regular expressions as i have used them for searching text files in windows based text editors. Since I am not very familiar with Unix, I dont understand when one should use GREP with the... (2 Replies)
Hi,
from my Windows Workstation I can connect with PUTTY to an AIX 6.1 unix server.
On AIX via PUTTY I run DBCA which has a grphical interface.
Then :
#DISPLAY=local_host:0.0 ; export DISPLAY
$(hostname) $(whoami):/appli/oracle/product/10.2.0/db_1/bin#dbca
_X11TransSocketINETConnect()... (12 Replies)
Hello. I'm trying to write a bash script that uses GNU screen and have hit a brick wall that has cost me many hours... (I'm sure it has something to do with quoting/globbing, which is why I post it here)
I can make a script that does the following just fine:
test.sh:
#!/bin/bash
# make... (2 Replies)
Hi,
Trying to change the prompt. I have the following code.
export PS1='
<${USER}@`hostname -s`>$ '
The hostname is not displayed
<abc@`hostname -s`>$ uname -a
AIX xyz 1 6 00F736154C00
<adcwl4h@`hostname -s`>$
If I use double quotes, then the hostname is printed properly but... (3 Replies)
Hello everyone,
I am working on a file with thousands of lines and instead of manually removing them I need a script to remove quotes within quotes. For example a line may have something such as this:
"Hey, I was ready to go on stage or "break a leg", but I failed miserably."
So I need to... (15 Replies)
Hi All,
I'm unable to load the data using sql loader where there are double quotes within the double quotes As these are optionally enclosed by double quotes.
Sample Data :
"221100",138.00,"D","0019/1477","44012075","49938","49938/15043000","Television - 22" Refurbished - Airwave","Supply... (6 Replies)
Discussion started by: mlavanya
6 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)