assigning variable in pipeline. Help!!!!

[suhaimi]

Hi,
How do I assign a variable in a pipeline? example:
file.txt content
aa
bb
cc

set var=" "
cat file.txt|tail -l|<do something so that var=&quot;cc&quot;>
echo $var
cc

I KNOW this method and DONOT want to use it for certain reasons:
set var=`cat file.txt|tail -l`


The variable assignment MUST BE in PIPELINE

Thanks,
Suhaimi

 

[sampsonr]

In ksh (or sh probably), you can do:

cat file.txt | tail -1 | read var

As an aside, cou can also shorten the pipleine by using:

tail -1 < file.txt | read var

 

[poet1964]

or you can do:

VAR=`cat file.txt|tail -1`

bye

 

[jamisar]

use unix basic commands:

var=`tail -1 filename`
-----------
when they don't ask you anymore, where they are come from, and they don't tell you anymore, where they go ... you'r getting older !

 

[suhaimi]

Hi sampsonr,
Thanks for the info. You're the only one who really know what I need. Unfortunately, it does not seem to be working.
Try this simple script

#!/bin/sh
echo &quot;test&quot;|read var
echo $var
It will return nothing! Please help!!!

Suhaimi

 

[suhaimi]

Can we do it in csh ?????

Suhaimi

 

[cspilman]

Try:

cat filename | tail -1 | while read var
do
echo ${var}
done
Regards,
Chuck

 

[sampsonr]

I don't know why but the sample script you cited works under /bin/ksh, but not under /bin/sh.

 

[suhaimi]

Hi,
How to do it in C shell??? Anybody???

Suhaimi

 

[tdatgod]

Hi,
In your original post you say....

cat file.txt|tail -l|<do something so that var=&quot;cc&quot;>

The variable assignment MUST BE in PIPELINE

Why can't you use

set var=`cat file.txt|tail -l`

I mean what comes after the

|<do something so that var=&quot;cc&quot;> | whats next?

maybe if we knew why you needed this we could come up with a solution.


Does The the line have more than one word? If so you need to add parenthesis in CSH.

set var= ( `cat file.txt|tail -l` )

another alternative is to

foreach i ( `cat file.txt|tail -l` )
.
.
.
end

which will in turn set $i to each word of the line. I tried the CSH equivlent


cat file.txt | tail -1 | set var = $<

but $< won't read from a PIPE and insists on reading from the keyboard.


Sorry I couldn't be of any help.

 

[tdatgod]

Hi,
I should point out what I like to do is

set var=`cat file.txt|tail -l`

Then on subsequent lines

echo $var | .....
echo $var | .....