Hi
I am writing a bash script and would like to check is a variable contains a . or not
ex.
a=102 output ok
a=1.02 output not ok
Many thanks, (3 Replies)
Hi,
I want to check if a variable has a value assigned to it or not.
I can do following -
cat $Var > File1
if
then
echo "$Var has value"
else
echo "$Var is null"
fi
But I have to check for 3 Variables and I want to wrap it up in couple of unix statements.
Any... (3 Replies)
Dear All,
we have a command output which looks like :
Total 200 queues in 30000 Kbytes
and we're going to get "200" and "30000" for further process. currently, i'm using :
numA=echo $OUTPUT | awk '{print $2}'
numB=echo $OUTPUT | awk '{print $5}'
my question is : can I use just one... (4 Replies)
I have seen many posts for this sort of problem but I just did not know how to use it for my issue. A number is assigned to a variable and I wanted to check if it is a zero or non zero.
Example of my numbers are below:
000000000000000000000000000000000000000000000000... (8 Replies)
Hi all,
Hope someone can help me out here.
I have this BASH script (see below)
My problem lies with the variable path.
The output of the command find will give me several fields. The 9th field is the path. I want to captured that and the I want to filter this to a specific level.
The... (6 Replies)
#!/bin/sh
echo "Running Script to capture ORACLE Erros"
# Change Directory to the actual logs path
cd /home/nv8510/lognew
err_var=`grep -in "ORA-" *`
if then
echo "THESE ARE THE ORACLE ERROR OCCURED"
echo "$err_var"
echo... (7 Replies)
Hello experts,
I'm stuck with this script for three days now. Here's what i need.
I need to split a large delimited (,) file into 2 files based on the value present in the last field.
Samp: Something.csv
bca,adc,asdf,123,12C
bca,adc,asdf,123,13C
def,adc,asdf,123,12A
I need this split... (6 Replies)
I have a script /root/asas with following contents.
#!/bin/bash
ha=`cat /etc/passwd | grep sandra`
if ; then
echo "Sandra is in /etc/passwd"
echo "variable ha is $ha"
else
echo "Sandra is NOT in /etc/passwd"
echo "variable ha is $ha"
fi
What... (3 Replies)
Hi people,
I would like to start a review of my config variable to check whether they have been changed and if not then there is only an echo. If they have been changed to my other commands are executed.
I hope you can help me.
with best regards
JPad
edit:
here my code
if ;... (8 Replies)
I have the following script, and I want to assign the output ($10 and $5) from awk to N and L:
grdinfo data.grd | awk '{print $10,$5}'| read N L
output from gridinfo data.grd is: data.grd 50 100 41 82 -2796 6944 0.016 0.016 3001 2461. where N and L is suppose to be 3001 and 100. I use... (8 Replies)
Discussion started by: geomarine
8 Replies
LEARN ABOUT PHP
empty
EMPTY(3) 1 EMPTY(3)empty - Determine whether a variable is emptySYNOPSIS
bool empty (mixed $var)
DESCRIPTION
Determine whether a variable is considered to be empty. A variable is considered empty if it does not exist or if its value equals FALSE.
empty(3) does not generate a warning if the variable does not exist.
PARAMETERS
o $var
- Variable to be checked
Note
Prior to PHP 5.5, empty(3) only supports variables; anything else will result in a parse error. In other words, the follow-
ing will not work: empty(trim($name)). Instead, use trim($name) == false.
No warning is generated if the variable does not exist. That means empty(3) is essentially the concise equivalent to !isset($var)
|| $var == false.
RETURN VALUES
Returns FALSE if $var exists and has a non-empty, non-zero value. Otherwise returns TRUE.
The following things are considered to be empty:
o "" (an empty string)
o 0 (0 as an integer)
o 0.0 (0 as a float)
o "0" (0 as a string)
o NULL
o FALSE
o array() (an empty array)
o $var; (a variable declared, but without a value)
CHANGELOG
+--------+---------------------------------------------------+
|Version | |
| | |
| | Description |
| | |
+--------+---------------------------------------------------+
| 5.5.0 | |
| | |
| | empty(3) now supports expressions, rather than |
| | only variables. |
| | |
| 5.4.0 | |
| | |
| | Checking non-numeric offsets of strings returns |
| | TRUE. |
| | |
+--------+---------------------------------------------------+
EXAMPLES
Example #1
A simple empty(3) / isset(3) comparison.
<?php
$var = 0;
// Evaluates to true because $var is empty
if (empty($var)) {
echo '$var is either 0, empty, or not set at all';
}
// Evaluates as true because $var is set
if (isset($var)) {
echo '$var is set even though it is empty';
}
?>
Example #2
empty(3) on String Offsets
PHP 5.4 changes how empty(3) behaves when passed string offsets.
<?php
$expected_array_got_string = 'somestring';
var_dump(empty($expected_array_got_string['some_key']));
var_dump(empty($expected_array_got_string[0]));
var_dump(empty($expected_array_got_string['0']));
var_dump(empty($expected_array_got_string[0.5]));
var_dump(empty($expected_array_got_string['0.5']));
var_dump(empty($expected_array_got_string['0 Mostel']));
?>
Output of the above example in PHP 5.3:
bool(false)
bool(false)
bool(false)
bool(false)
bool(false)
bool(false)
Output of the above example in PHP 5.4:
bool(true)
bool(false)
bool(false)
bool(false)
bool(true)
bool(true)
NOTES
Note
Because this is a language construct and not a function, it cannot be called using variable functions.
Note
When using empty(3) on inaccessible object properties, the __isset() overloading method will be called, if declared.
SEE ALSO isset(3), __isset(), unset(3), array_key_exists(3), count(3), strlen(3), The type comparison tables.
PHP Documentation Group EMPTY(3)