07-04-2013
Does a variable lose its value outside the loop in shell script?
hi,
when we assign a variable inside a for loop or while loop in a shell script, does it loses its value after comming out of the loop. i am facing this issue.
can anyone help me??
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
I am a newbie to awk and c programming, however am not a unix newbie. However, I do need help with a kshell script I am writing. It is almost complete, the last step is killing me. Any help would be greatly appreciated. What I am trying to do is cat a text file that has usernames. Then, using... (2 Replies)
Discussion started by: synergy_texas
2 Replies
2. Shell Programming and Scripting
Hi,
I have a text file with data in that I wish to extract, assign to a variable and process through a loop.
Kind of the process that I am after:
1: Grep the text file for the values.
Currently using:
cat /root/test.txt | grep TESTING= | awk -F"=" '{ a = $2 } {print a}' | sort -u
... (0 Replies)
Discussion started by: Spoonless
0 Replies
3. Shell Programming and Scripting
Hi all
I run my program prog.c in the following way :
$ ./prog 1 > output.txt where 1 is a user defined initial value used by the program.
But now I want to run it for many a thousand initial values, 1-1000, and store all the outputs in different files.
Like
$ ./prog 1... (1 Reply)
Discussion started by: alice06
1 Replies
4. Shell Programming and Scripting
Hello
I am having issues with a script I'm working on developing on a Solaris machine.
The script is intended to find out how many times a particular user (by given userid) has logged into the local system for more than one hour today.
Here is my while loop:
last $user | grep -v 'sshd'... (7 Replies)
Discussion started by: DaveRich
7 Replies
5. Shell Programming and Scripting
Hello Everyone,
I'm still trying to grasp many concepts in .ksh scripting, one of them being variables inside loops. My problem is the following:
* I'm trying to set a variable inside a while read loop to reuse it outside of said loop. My lines are the following :... (13 Replies)
Discussion started by: jimmy75_13
13 Replies
6. Shell Programming and Scripting
Hello,
I'm having trouble with formatting some text via the terminal. I can get it perfectly formatted, but when I try and copy paste the text from the output file it loses it's formatting. Very frustrating!
Basically I have 7 files (data data2 data3 data4 data5 data6 data7) containing a... (13 Replies)
Discussion started by: facetoe
13 Replies
7. Shell Programming and Scripting
Simple enough problem I think, I just can't seem to get it right.
The below doesn't work as intended, it's just a function defined in a much larger script:
CheckValues() {
for field in \
Group_ID \
Group_Title \
Rule_ID \
Rule_Severity \
... (2 Replies)
Discussion started by: Vryali
2 Replies
8. Shell Programming and Scripting
I have a shell script (.sh) and I want to pass a parameter value to the awk command but I am getting exception, please assist.
diff=$1$2.diff
id=$2 new=new_$diff
echo "My id is $1"
echo "I want to sync for user account $id"
##awk command I am using is as below
cat $diff | awk... (2 Replies)
Discussion started by: Ashunayak
2 Replies
9. Shell Programming and Scripting
I want to create a shell script to add a user and modify its comment field mentioned in a file.
1.
File value:-
username comment field value
xyz123 xyztesting
abc123 abctesting
def123 deftesting
2. i am using below loop to create user... (2 Replies)
Discussion started by: Anil
2 Replies
10. UNIX for Beginners Questions & Answers
I have if loop with multiple variable value check in if loop. How can i print only if loop satisfied variable and its value in shell script ? I dont want to check each variable in if loop. That makes my script larger.
if ]
then
echo "Only satisfied variable with value"
... (3 Replies)
Discussion started by: prince1987
3 Replies
LEARN ABOUT CENTOS
foreach
foreach(n) Tcl Built-In Commands foreach(n)
__________________________________________________________________________________________________________________________________________________
NAME
foreach - Iterate over all elements in one or more lists
SYNOPSIS
foreach varname list body
foreach varlist1 list1 ?varlist2 list2 ...? body
_________________________________________________________________
DESCRIPTION
The foreach command implements a loop where the loop variable(s) take on values from one or more lists. In the simplest case there is one
loop variable, varname, and one list, list, that is a list of values to assign to varname. The body argument is a Tcl script. For each
element of list (in order from first to last), foreach assigns the contents of the element to varname as if the lindex command had been
used to extract the element, then calls the Tcl interpreter to execute body.
In the general case there can be more than one value list (e.g., list1 and list2), and each value list can be associated with a list of
loop variables (e.g., varlist1 and varlist2). During each iteration of the loop the variables of each varlist are assigned consecutive
values from the corresponding list. Values in each list are used in order from first to last, and each value is used exactly once. The
total number of loop iterations is large enough to use up all the values from all the value lists. If a value list does not contain enough
elements for each of its loop variables in each iteration, empty values are used for the missing elements.
The break and continue statements may be invoked inside body, with the same effect as in the for command. Foreach returns an empty string.
EXAMPLES
This loop prints every value in a list together with the square and cube of the value:
set values {1 3 5 7 2 4 6 8} ;# Odd numbers first, for fun!
puts "Value Square Cube" ;# Neat-looking header
foreach x $values { ;# Now loop and print...
puts " $x [expr {$x**2}] [expr {$x**3}]"
}
The following loop uses i and j as loop variables to iterate over pairs of elements of a single list.
set x {}
foreach {i j} {a b c d e f} {
lappend x $j $i
}
# The value of x is "b a d c f e"
# There are 3 iterations of the loop.
The next loop uses i and j to iterate over two lists in parallel.
set x {}
foreach i {a b c} j {d e f g} {
lappend x $i $j
}
# The value of x is "a d b e c f {} g"
# There are 4 iterations of the loop.
The two forms are combined in the following example.
set x {}
foreach i {a b c} {j k} {d e f g} {
lappend x $i $j $k
}
# The value of x is "a d e b f g c {} {}"
# There are 3 iterations of the loop.
SEE ALSO
for(n), while(n), break(n), continue(n)
KEYWORDS
foreach, iteration, list, looping
Tcl foreach(n)