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MEMO: Issue with a for loop

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Top Forums Shell Programming and Scripting MEMO: Issue with a for loop
# 1  
Old 05-11-2011
Network MEMO: Issue with a for loop
Can someone help me what i am doing wrong with this:
Code:
apsrvrport1=28548
stcmsport1=28507
apsrvrport2=38548
stcmsport2=38507
apsrvrport3=48548
stcmsport3=48507
apsrvrport4=58548
stcmsport4=58507
apsrvrport5=38048
stcmsport5=38007
apsrvrport6=27548
stcmsport6=27507
apsrvrport7=37548
stcmsport7=37507
apsrvrport8=18548
stcmsport8=18507
emanager1=15500
emanager2=15600
echo " ..................Collecting lsof command information..............."
for i in 1 2 3 4 5 6 7 8
do
serverlsof$i=`lsof |grep *:$apsrvrport$i | awk '{print $2}'`
echo "PID = $appserver$i"
done

when I run it:
Code:
mytest.sh[40]: serverlsof1=: not found.
PID = 1

I have two issues: 1) I am getting an error on the serverlsof$i
2) Why the PID is capturing the counter !! hopw can I pass the actual value of the lsof command in this case?

Thank you
Last edited by vbe; 05-11-2011 at 10:36 AM.. Reason: code tags are to be used...
# 2  
Old 05-11-2011
From a syntax point of view the script needs to use "eval" wherever a changeable variable name occurs to stop the variables being evaluated on the first pass through the Shell.
My interpretation of what you intended (untested):

Code:
for i in 1 2 3 4 5 6 7 8
do
  eval serverlsof$i=`lsof |grep *:\$apsrvrport$i | awk '{print $2}'`
  eval echo "PID = \$appserver$i"
done


Personally I would have used a case statement to set unsuffixed environment variables. Other scripters might use an array. Other scripters would "source" parameter files (one per suffix).
# 3  
Old 05-11-2011
Fixed the first issue, But the echo PID line is not displaying the result of the lsof command: it is display this line 8 times:
PID = spaces
# 4  
Old 05-11-2011
You never assigned any values to the variable "\$appserver$i" and hence it is printing nothing. Revisit your logic once more.

regards,
Ahamed
# 5  
Old 05-12-2011
Code:
for i in 1 2 3 4 5 6 7 8
    do
       eval serverlsof$i=`lsof |grep *:\$apsrvrport$i | awk '{print $2}'`
       eval echo "PID = \$serverlsof$i"
    done

Still the same issue.
Moderator's Comments:
Mod Comment
Please use code tags when posting data and code samples!


---------- Post updated at 11:06 PM ---------- Previous update was at 02:39 PM ----------

Need someone who knows about this to respond.
Last edited by vgersh99; 05-11-2011 at 04:41 PM.. Reason: code tags, please!
# 6  
Old 05-23-2011
any takerrrrrrs?
# 7  
Old 05-23-2011
That eval trick is a nightmare with a complex command like that. You'll need a lot more backslashes to get it working. Use arrays instead.
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