I was reading Bash Cookbook and it had a line of command that assigned a value from var2 to var1 if var1 was empty. Someone told me I could do the same with ${parameter}.
I'm just trying to understand this. Would the following be correct?
For:
Code:
answer=
default=1
Should I assume that the two lines bellow will do the same?
Say I write something like the following:
var1=1
var2=2
for int in 1 2
do
echo "\$var$int"
done
I want the output to be:
1
2
Instead I get something like:
$var1
$var2 (2 Replies)
I just started shell coding and I'm a bit confused on how 'mv' works can someone explain to me how it works and if i did this correctly. Thanks.
echo "Enter Name of the first file:"
read file1
#echo $file1
if ; then
echo "Sorry, file does not exist."
exit 1
... (16 Replies)
Hi Gurus:
I am trying to understand the following line of code.I did enough of googling to understand but no luck.Please help me understand the follow chunk of code:
X=$0
MOD=${X%/*}/env.ksh
X is the current script from which I am trying to execute.
Say if X=test.ksh
$MOD is echoing :... (3 Replies)
Hi
I am looking for a unix command or a small shell script which can takes one parameter and then searches for the passed in the parameter in any or all files under say /home/dev/
Can anyone please help me on this? (3 Replies)
i am passing input parameter 'one_two' to the script , the script output should display the result as below
one_1two
one_2two
one_3two
if
then
echo " Usage : <$0> <DATABASE> "
exit 0
else
for DB in 1 2 3
do
DBname=`$DATABASE | awk -F "_" '{print $1_${DB}_$2}`
done
fi (5 Replies)
hi all,
i have a parameter file of following format, i want a method which can get the value of specific parameter.
parameter file format:
<Parameter Name="FileLocationWindows">
<Description>
The directory location of the logger file.
... (1 Reply)
Hi,
I have the following files.
->cat scr.sh
export TMP_DIR=/home/user/folder1
export TMP_DIR_2=/home/user/folder2
while read line
do
cat "$line"
done<file_list.dat
------------------------
-> cat file_list.dat
$TMP_DIR/file1.txt
$TMP_DIR_2/file2.txt
---------------------------
-> cat... (6 Replies)
Hi.
How do I achieve this
sh /EDWH-DMT02/script/MISC/exec_sql.sh "@/EDWH-DMT02/script/others/CSM_CKC/Complete_List.sql ${file_name}" Complete_List.txt
The /EDWH-DMT02/script/MISC/exec_sql.sh has two parameters and it's working fine with this
sh /EDWH-DMT02/script/MISC/exec_sql.sh... (7 Replies)
Hello All,
Could you please do help me here as I would like to perform parameter expansion in shell over a parameter expansion.
Let's say I have following variable.
path="/var/talend/nat/cdc"
Now to get only nat I could do following.
path1="${path%/*}"
path1="${path1##*/}"
Here... (8 Replies)
Discussion started by: RavinderSingh13
8 Replies
LEARN ABOUT PHP
list
LIST(3) 1 LIST(3)list - Assign variables as if they were an arraySYNOPSIS
array list (mixed $var1, [mixed $...])
DESCRIPTION
Like array(3), this is not really a function, but a language construct. list(3) is used to assign a list of variables in one operation.
PARAMETERS
o $var1
- A variable.
RETURN VALUES
Returns the assigned array.
EXAMPLES
Example #1
list(3) examples
<?php
$info = array('coffee', 'brown', 'caffeine');
// Listing all the variables
list($drink, $color, $power) = $info;
echo "$drink is $color and $power makes it special.
";
// Listing some of them
list($drink, , $power) = $info;
echo "$drink has $power.
";
// Or let's skip to only the third one
list( , , $power) = $info;
echo "I need $power!
";
// list() doesn't work with strings
list($bar) = "abcde";
var_dump($bar); // NULL
?>
Example #2
An example use of list(3)
<table>
<tr>
<th>Employee name</th>
<th>Salary</th>
</tr>
<?php
$result = $pdo->query("SELECT id, name, salary FROM employees");
while (list($id, $name, $salary) = $result->fetch(PDO::FETCH_NUM)) {
echo " <tr>
" .
" <td><a href="info.php?id=$id">$name</a></td>
" .
" <td>$salary</td>
" .
" </tr>
";
}
?>
</table>
Example #3
Using nested list(3)
<?php
list($a, list($b, $c)) = array(1, array(2, 3));
var_dump($a, $b, $c);
?>
int(1)int(2)int(3)
Example #4
Using list(3) with array indices
<?php
$info = array('coffee', 'brown', 'caffeine');
list($a[0], $a[1], $a[2]) = $info;
var_dump($a);
?>
Gives the following output (note the order of the elements compared in which order they were written in the list(3) syntax):
array(3) {
[2]=>
string(8) "caffeine"
[1]=>
string(5) "brown"
[0]=>
string(6) "coffee"
}
NOTES
Warning
list(3) assigns the values starting with the right-most parameter. If you are using plain variables, you don't have to worry about
this. But if you are using arrays with indices you usually expect the order of the indices in the array the same you wrote in the
list(3) from left to right; which it isn't. It's assigned in the reverse order.
Warning
Modification of the array during list(3) execution (e.g. using list($a, $b) = $b) results in undefined behavior.
Note
list(3) only works on numerical arrays and assumes the numerical indices start at 0.
SEE ALSO each(3), array(3), extract(3).
PHP Documentation Group LIST(3)