Read from file and execute the read command


 
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# 1  
Old 09-05-2013
Question Read from file and execute the read command

Hi,

I am facing issues with the below:
I have a lookup file say lookup.lkp.This lookup.lkp file contains strings delimited by comma(,).

Now i want to read this command from file and execute it.
So my code below is :
Contents in the lookup.lkp file is :
Code:
c_e,m,a,`cd $BOX | ls cef_*|tail -1`,/home/me

In my shell script I read it as :
Code:
$(cat lookup.lkp | grep c_e | cut -d ',' -f4)

So above command should pick up
Code:
`cd $BOX | ls cef_*|tail -1`

which it does....but the command does not return the file name starting with cef_some_name even though there are files which match the wildcard.
Instead it quits using no such file or directory.

How can I execute this.Any help appreciated.

Last edited by Scrutinizer; 09-05-2013 at 03:30 PM.. Reason: code tags
# 2  
Old 09-05-2013
Try:
Code:
eval $(cat lookup.lkp | grep c_e | cut -d ',' -f4)

# 3  
Old 09-05-2013
Quote:
Originally Posted by bartus11
Try:
Code:
eval $(cat lookup.lkp | grep c_e | cut -d ',' -f4)

Hi,
Thanks for the reply.

But the above code does not help.
It gives the below error :

Code:
ls: cef_*: No such file or directory

Can you please help me out.
# 4  
Old 09-05-2013
Two things to change in your lookup file:
a) don't pipe the cd $BOX to the next statement as it doen't make sense - cd has no output and ls doesn't read stdin.
b) strip the backticks off that entire command list; they make it try to execute the result of the ls, which is some cef_* file which is not executable.

Try sth like
Code:
c_e,m,a,cd $BOX ; ls cef_*|tail -1,/home/me

in the lookup file.
# 5  
Old 09-05-2013
Quote:
Originally Posted by RudiC
Two things to change in your lookup file:
a) don't pipe the cd $BOX to the next statement as it doen't make sense - cd has no output and ls doesn't read stdin.
b) strip the backticks off that entire command list; they make it try to execute the result of the ls, which is some cef_* file which is not executable.

Try sth like
Code:
c_e,m,a,cd $BOX ; ls cef_*|tail -1,/home/me

in the lookup file.
If the intention is to not run the ls cef_*|tail -1 if the cd $BOX failed, then use
Code:
cd $BOX && ls cef_*|tail -1

# 6  
Old 09-08-2013
Hi Thanks for the replies.
But i have been getting the same error.
So in my lookup i have mentioned as
Code:
echo /a/b/c/box/$(ls -rt /a/b/c/box|grep -i cef |tail -1)

and to get this above stmt to execute and assign to ftf is :
Code:
ftf=$(eval $(cat $file_path | grep -i $STR | cut -d '*' -f4))

This is working for me....but as you can see in my lookup file i have hardcoded the path.
So the issue remains I have to parametrize this value.

Which could be :
Code:
echo $(ls -rt $BOX |grep -i cef |tail -1)

But this $BOX don't seem to resolve.I even tried \$BOX to resolve.
But it doesnt seem to resolve the value.

Can anyone please suggest some solution.
# 7  
Old 09-08-2013
You lost me - sorry. What's the result of cat $file_path | grep -i $STR | cut -d '*' -f4?
Why don't you execute the relevant part of your code with the xtrace option on and post the result?
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