Is it possible to store a command inside a variable?
i want this piece to be stored inside a variable, so i can use it later in a different command
I tried to use eval but I receive this error:
Anyone know if this is possible?
Thanks
I agree with everything Chubler_XL, Corona688, and neutronscott have said, but just to be clear, the error you are getting is not from the eval; it is from the command:
which sets var to the string $u | cut -d (with $u expanded to the the current contents of the variable u) and exports var into the environment of the command -f 2 (which the shell did not find on your search path).
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)
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)
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)
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)
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)
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)
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)
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)
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)
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
LEARN ABOUT REDHAT
while
while(n) Tcl Built-In Commands while(n)
__________________________________________________________________________________________________________________________________________________NAME
while - Execute script repeatedly as long as a condition is met
SYNOPSIS
while test body
_________________________________________________________________DESCRIPTION
The while command evaluates test as an expression (in the same way that expr evaluates its argument). The value of the expression must a
proper boolean value; if it is a true value then body is executed by passing it to the Tcl interpreter. Once body has been executed then
test is evaluated again, and the process repeats until eventually test evaluates to a false boolean value. Continue commands may be exe-
cuted inside body to terminate the current iteration of the loop, and break commands may be executed inside body to cause immediate termi-
nation of the while command. The while command always returns an empty string.
Note: test should almost always be enclosed in braces. If not, variable substitutions will be made before the while command starts execut-
ing, which means that variable changes made by the loop body will not be considered in the expression. This is likely to result in an
infinite loop. If test is enclosed in braces, variable substitutions are delayed until the expression is evaluated (before each loop iter-
ation), so changes in the variables will be visible. For an example, try the following script with and without the braces around $x<10:
set x 0
while {$x<10} {
puts "x is $x"
incr x
}
SEE ALSO
break(n), continue(n), for(n), foreach(n)
KEYWORDS
boolean value, loop, test, while
Tcl while(n)