I need to do something like this:
for i in 1 2 3 4 5; do
arr=$(awk 'NR="$i" { print $2 }' file_with_5_records)
done
That is, parse a file and assign values to an array in an ascending order relative to the number of record in the file that is being processed on each loop.
Is my... (2 Replies)
I'm trying to understand if it's possible to create a set of variables that are numbered based on another variable (using eval) in a loop, and then call on it before the loop ends.
As an example I've written a script called question (The fist command is to show what is the contents of the... (2 Replies)
Hi,
Please help me writing for loop to fetch data and store in variable from a text file which contains data as below:
12
46
56
5466
111
There are 40 lines of data...!!!!
I jus need all data from line no 4 to 40 ie data for 4,6,8......40. (2 Replies)
Hi ,
i am using below code print the PATH value inside for loop but it's printing just PATHD & not the original value which i defined.
#!/usr/bin/bash
PATHD1=/spp/sp/LIVE
export PATHD1
PATHD2=/spp/sp/TEST
export PATHD2
j=2
for (( i = 1 ; i <= j ; i++ ))
do
PATH_DIR=PATH$i
echo PATHD$i... (2 Replies)
Hi all
Sorry for the basic question, but i am writing a shell script to get around a slightly flaky binary that ships with one of our servers. This particular utility randomly generates the correct information and could work first time or may work on the 12th or 100th attempt etc !.... (4 Replies)
Hi All,
I have a fixed-width datafile from which i need to extract value/string starting from some position to the specified length in each of the lines.
awk '{print substr($0,x,y)}' datafile --- is working fine
but
awk 'BEGIN{a=0}{a=substr($0,x,y);print $a}' datafile ---is giving... (3 Replies)
Please help me to automatically assign the output of awk command to the variables cs3, cs4, cs5 and cs6 using a for loop. The below code is not working.
for i in 3 4 5 6
do
cs$i=`awk -F"|" 'BEGIN{sum=0}{sum=sum+$'$i'}END{printf("%d\n", sum)}' css`
done
echo $cs3 $cs4 $cs5 $cs6 (9 Replies)
echo "hello123" | tr -dc '' | wc -c
using this command i can count the no of times a number from 0-9 occurs in the string "hello123"
but how do i save this result inside a variable?
if i do
x= echo "hello123" | tr -dc '' | wc -c
that does not work...plz suggest..thanks (3 Replies)
Hi All,
Is it possible to grep for two files and assign their names to two separate variables with for loop? I am doing the below currently:
if
then
for fname in $( cd $dirA ; ls -tr | grep "^Ucountry_file$")
do
InFile=$dirA/$fname
... (4 Replies)
Discussion started by: swasid
4 Replies
LEARN ABOUT PHP
eval
EVAL(3) 1 EVAL(3)eval - Evaluate a string as PHP codeSYNOPSIS
mixed eval (string $code)
DESCRIPTION
Evaluates the given $code as PHP.
Caution
The eval(3) language construct is very dangerous because it allows execution of arbitrary PHP code. Its use thus is discouraged.
If you have carefully verified that there is no other option than to use this construct, pay special attention not to pass any user
provided data into it without properly validating it beforehand.
PARAMETERS
o $code
- Valid PHP code to be evaluated. The code mustn't be wrapped in opening and closing PHP tags, i.e. 'echo "Hi!";' must be passed
instead of '<? echo "Hi!"; >'. It is still possible to leave and reenter PHP mode though using the appropriate PHP tags, e.g.
'echo "In PHP mode!"; ?>In HTML mode!<? echo "Back in PHP mode!";'. Apart from that the passed code must be valid PHP. This
includes that all statements must be properly terminated using a semicolon. 'echo "Hi!"' for example will cause a parse error,
whereas 'echo "Hi!";' will work. A return statement will immediately terminate the evaluation of the code. The code will be exe-
cuted in the scope of the code calling eval(3). Thus any variables defined or changed in the eval(3) call will remain visible
after it terminates.
RETURN VALUES eval(3) returns NULL unless return is called in the evaluated code, in which case the value passed to return is returned. If there is a
parse error in the evaluated code, eval(3) returns FALSE and execution of the following code continues normally. It is not possible to
catch a parse error in eval(3) using set_error_handler(3).
EXAMPLES
Example #1
eval(3) example - simple text merge
<?php
$string = 'cup';
$name = 'coffee';
$str = 'This is a $string with my $name in it.';
echo $str. "
";
eval("$str = "$str";");
echo $str. "
";
?>
The above example will output:
This is a $string with my $name in it.
This is a cup with my coffee in it.
NOTES
Note
Because this is a language construct and not a function, it cannot be called using variable functions.
Tip
As with anything that outputs its result directly to the browser, the output-control functions can be used to capture the output of
this function, and save it in a string (for example).
Note
In case of a fatal error in the evaluated code, the whole script exits.
SEE ALSO call_user_func(3).
PHP Documentation Group EVAL(3)