Hi...
I'm new here and i have a Q...
How do i get only the number from a string?
like from "rlvol11" i want to get 11
or from "lvol4" i want to get 4
what commands should i use at my script?
thanx 4 the help!
Eliraz. (13 Replies)
I writing my script and got stuck in this function. Can someone help me?
I need to extract out the numbers inside a string.
Ex:
INPUT -> OUTPUT
abcdef123 -> 123
abc123def -> 123
123abcdef -> 123
a123bc45d -> 123 45
abcdefghi -> -1
Thank you! (12 Replies)
Hi,
I need help to sort a file contents.
I am using sort -r option to basically reverse the comparison in descending order. However, i found out that my file is not sorted according, can anyone please help.
My data is something like:-
Hello world
20.982342864 343
19.234355545 222... (5 Replies)
Dear Unix Gurus,
I have a list of files that I want to loop over....for example:
sl40_z11.70.txt
sl41_z11.40.txt
sl42_z11.10.txt
sl43_z10.80.txt
using the script
#!/bin/sh
#
echo -n "....enter first Z-coordinate position....."; read zpos
q="scale=3; $zpos"
p=0.3
#... (7 Replies)
Hi Everyone,
I have:
$val="QQ3_1899_CD4".
The output will be:
1899.
I did $val =~ /(\d+)/g; the output is 318994, then i use substr to get those 1899. This is not efficient.
Is any simple way, like just one line can do? Thanks (1 Reply)
Hi,
I want to display the string value with number value. I dont know how to display. Can anyone help me.
This is my code
export A=${file_name}
echo $a $b $sum | awk '{ printf "%011.f,%014.f,%014.f\n", $1,$2,$3}' >> ${MRR_OUTPUT}
the out put shold be
${A}, $a, $b
filename,... (2 Replies)
Hello Everyone,
i have quick question.
I have file names like: bin_map300.asc and I would like to extract grid300.
My approach so far:
name=bin_map300.asc
echo ${name%%.*}
echo ${name##*_}
I am stuck combining the two.
Any help would be appreciated. (3 Replies)
Hi all,
I'm a new programmer to shell script... and I have no idea how to use substring.
I want to extract the numbers from the following string and place it into a variable:
"170 unique conformations found"
The numbers can be more than three digits depending on the case. I just want to... (10 Replies)
I am writing a bash script on ubuntu11.10
I have some string having numbers and letter and want to add all the numbers together
For example
1s2d23f
I want to perform
1 + 2 + 23 and store it in a variable (3 Replies)
Hi,
I am having contents in a file like below,
cat testfile
rpool/swap
rpool/swap14
rpool/swap2
rpool/swap3
I want to sort the above contents like,
rpool/swap
rpool/swap2
rpool/swap3
rpool/swap14
I have tried in this way, (7 Replies)
Discussion started by: Sumanthsv
7 Replies
LEARN ABOUT PHP
unset
UNSET(3) 1 UNSET(3)unset - Unset a given variableSYNOPSIS
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)