problem with read command

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# 1  
Old 08-06-2009
problem with read command

Hi Guys,

I am just trying to read data from a file.
The command i tried worked well with AIX server. But in SunOS, it is not reading.

cat log.out |sed -n '4,4p'| read value;
+ sed -n 4,4p
+ cat log.out
+ read value
echo $value;
+ echo

This is the log of running the script.

Can you people help me in figuring it out.. and also i want to know how the same command which worked on AIX is not working in SunOS.

Thanks & Regards,
# 2  
Old 08-06-2009
I guess you are just going to get the 4th line.
The cat is not needed since sed can read files on it's own.

In bash you can do this
read VAR < <(sed '4!d' infile)
echo $VAR

This should work in most shells and would also need no read:
VAR=`sed '4!d' infile`
echo $VAR

# 3  
Old 08-06-2009
zaxxon do we need to have two "<" in the code?
# 4  
Old 08-06-2009
We have Posix-standard and then we have real world Smilie - people who has done the shells.

Only in ksh you can use pipe:
cmd | read var1 var2 ...

Previous zaxxon example include howto read generic one variable:
var=$( cmd )

Previous zaxxon example include howto read more than one variable using bash.
read var1 var2 <  <(cmd)

Generic version for more than one variable read:
read var1 var2 <<EOF

Last edited by kshji; 08-06-2009 at 04:33 AM..
# 5  
Old 08-06-2009
KShJi, i am using a ksh only..

But still why i am not able to pass the value to the read command ?

Can you please explain me?

Thanks in advance
# 6  
Old 08-06-2009
cat log.out | sed -n '4,4p'| read value
echo "$value"

Works fine with ksh88 and ksh93. Just tested - echo something, if log.out has more than 3 lines.
# 7  
Old 08-06-2009
this is the content of my file
tcmsd003:/usr/local/dsadm/dsprod/src>cat log.out


Actually from the unix prompt if i run the same sed command, i am getting the desired output, in this case 1. But i have problem in the script only

---------- Post updated at 01:24 PM ---------- Previous update was at 01:23 PM ----------

This is the output of my sed command.
tcmsd003:/usr/local/dsadm/dsprod/src>sed -n '4,4p' log.out

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