10-16-2014
Also, it will assign the value of $u right then, and not get any "new" value when you use it later.
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hi all..
I got a problem..
Its easy to redirect o/p to a file.. But Is it possible to redirect the O/P to a variable?
For example:
I've a command in my script:
string1=cut -d ':' -f2 file.txt
When I do:
echo $string1
The value is empty... Pls suggest me how to store the value... (7 Replies)
Discussion started by: smartbuddy
7 Replies
2. Shell Programming and Scripting
I have a variable A
echo $A
5060
I am exporting the value X,Y,Z and it id fetching right thing and When I run
C=`${X} -l ${Y} ${Z} "trap '' INT;. ~/.profile >/dev/null 2>/dev/null; netstat -na | grep \$A`"
here it is going to same directory and also running netstat -na | grep 5060
... (4 Replies)
Discussion started by: madhusmita
4 Replies
3. Shell Programming and Scripting
Hi Jim,
The following script is in working state. But i m having one more problem with awk cmd. Could you tell me how to use any variable inside awk or how to take any variable value outside awk.
My problem is i want to maintain one property file in which i am declaring variable value into that... (12 Replies)
Discussion started by: Ganesh Khandare
12 Replies
4. Shell Programming and Scripting
I am sure it has been answered in some form or the other in this forum but trust me I have spent last couple of hours looking for an answer but can't find it.
I want to do a very simple operation within my script.
Let's say I have 4 files with the names file1.log, file2.log, file3.log and... (6 Replies)
Discussion started by: sssccc
6 Replies
5. Shell Programming and Scripting
Hi,
I am trying to do the following thing
var='date'
$var
Above command substitutes date for and in turn runs the date command and i am getting the todays date value.
I am trying to do the same thing as following, but facing some problems,
unique_host_pro="sed -e ' /#/d'... (3 Replies)
Discussion started by: gvinayagam
3 Replies
6. Shell Programming and Scripting
Hello Experts
I am newbie to unix and writing one script to make archive files
Problme i am facing is : I have used find command to find the type of files and I am storing find command results in a variable.
When I echo the variable I can see that path is printed properly but when i am... (5 Replies)
Discussion started by: mitsyjohn
5 Replies
7. Shell Programming and Scripting
Hi
How to use a variable to store the filename of a file which was found by the 'find' command.
can this be practical-->var = find . -name "filename.dat"
Please help.. (1 Reply)
Discussion started by: ayyappaas
1 Replies
8. Shell Programming and Scripting
Hello All
My req is to store the exit status of a command in shell variable
I want to check whether the file has header or not
The header will contain the string
DATA_ACQ_CYC_CNTL_ID
So I am running the command
head -1 $i | grep DATA_ACQ_CYC_CNTL_ID
Now I have to check if... (6 Replies)
Discussion started by: Pratik4891
6 Replies
9. Shell Programming and Scripting
I want to store the return value of
grep -c string filename
into a variable, say count. How do I do that?
For example if grep -c "string" "filename" shows 0 on executing it in the sh shell then I want to store this 0 in a variable. Is it possible? :D (5 Replies)
Discussion started by: navienavnav
5 Replies
10. Programming
I am trying to store output of python command in variable. Could you please help how I can do that ?
For example I am executing the following command - "CentOS" in server_desc
The output would be True or False
I would like to store the output in a variable say outPut and use condition... (4 Replies)
Discussion started by: atanubanerji
4 Replies
UNSET(3) 1 UNSET(3)
unset - Unset a given variable
SYNOPSIS
void unset (mixed $var, [mixed $...])
DESCRIPTION
unset(3) destroys the specified variables.
The behavior of unset(3) inside of a function can vary depending on what type of variable you are attempting to destroy.
If a globalized variable is unset(3) inside of a function, only the local variable is destroyed. The variable in the calling environment
will retain the same value as before unset(3) was called.
<?php
function destroy_foo()
{
global $foo;
unset($foo);
}
$foo = 'bar';
destroy_foo();
echo $foo;
?>
The above example will output:
bar
To unset(3) a global variable inside of a function, then use the $GLOBALS array to do so:
<?php
function foo()
{
unset($GLOBALS['bar']);
}
$bar = "something";
foo();
?>
If a variable that is PASSED BY REFERENCE is unset(3) inside of a function, only the local variable is destroyed. The variable in the
calling environment will retain the same value as before unset(3) was called.
<?php
function foo(&$bar)
{
unset($bar);
$bar = "blah";
}
$bar = 'something';
echo "$bar
";
foo($bar);
echo "$bar
";
?>
The above example will output:
something
something
If a static variable is unset(3) inside of a function, unset(3) destroys the variable only in the context of the rest of a function. Fol-
lowing calls will restore the previous value of a variable.
<?php
function foo()
{
static $bar;
$bar++;
echo "Before unset: $bar, ";
unset($bar);
$bar = 23;
echo "after unset: $bar
";
}
foo();
foo();
foo();
?>
The above example will output:
Before unset: 1, after unset: 23
Before unset: 2, after unset: 23
Before unset: 3, after unset: 23
PARAMETERS
o $var
- The variable to be unset.
o $...
- Another variable ...
RETURN VALUES
No value is returned.
EXAMPLES
Example #1
unset(3) example
<?php
// destroy a single variable
unset($foo);
// destroy a single element of an array
unset($bar['quux']);
// destroy more than one variable
unset($foo1, $foo2, $foo3);
?>
Example #2
Using (unset) casting
(unset) casting is often confused with the unset(3) function. (unset) casting serves only as a NULL-type cast, for completeness. It
does not alter the variable it's casting.
<?php
$name = 'Felipe';
var_dump((unset) $name);
var_dump($name);
?>
The above example will output:
NULL
string(6) "Felipe"
NOTES
Note
Because this is a language construct and not a function, it cannot be called using variable functions.
Note
It is possible to unset even object properties visible in current context.
Note
It is not possible to unset $this inside an object method since PHP 5.
Note
When using unset(3) on inaccessible object properties, the __unset() overloading method will be called, if declared.
SEE ALSO
isset(3), empty(3), __unset(), array_splice(3).
PHP Documentation Group UNSET(3)