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sed to read

 
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# 1  
Old 12-01-2009
sed to read
Hi all,
is it possible to pipe the output of sed to read?
I'm using bash I tried

Code:
sed -n '2p' file.dat | read var1 var2
echo $var1 $var2

without success

Code:
sed -n '2p' file.dat

gives
Code:
  5.43518733E+07          4.05545247E+13

as expected

thank you,
Sarah
# 2  
Old 12-01-2009
bash shell
Code:
exec 4<"file"
read line<&4; read line<&4
exec 4>&-
set -- $line
var1=$1
var2=$2
echo "$var1 $var2"

# 3  
Old 12-01-2009
Or

Code:
read var1 var2 junk << !
$(sed -n '2p' file1)
!

# 4  
Old 12-01-2009
thank you very much.

the solution

Code:
read var1 var2 junk << !
$(sed -n '2p' file1)
!

it works fine alone
I have it in a for loop and I get the error

Code:
line 54: syntax error: unexpected end of file

as soon as enter that code
Last edited by f_o_555; 12-01-2009 at 07:16 AM..
# 5  
Old 12-01-2009
Without seeing your code, I would have no idea why...
# 6  
Old 12-01-2009
Code:
sed -n '2p' file.dat | read var1 var2
echo $var1 $var2

will work as you would expect in ksh, but not in the other shells.

Otherwise, alternatives to Scottn' s solution :
Code:
sed -n '2p' file.dat | { read var1 var2
echo $var1 $var2 ;}

-or if your platform supports it
Code:
read var1 var2 < <(sed -n '2p' file.dat)
echo $var1 $var2

-or if your shell supports it:
Code:
read var1 var2 <<< $(sed -n '2p' file.dat)
echo $var1 $var2

The latter is small variation to scottn's code and work in bash and ksh93
# 7  
Old 12-01-2009
Quote:
Originally Posted by scottn
Without seeing your code, I would have no idea why...
this is the code

Code:
#!/bin/bash
TOT=`wc -l < $1`
PART=$(($TOT / 16))
echo $1 $TOT $PART

echo "FAKE 1" > xxx
echo "FAKE 1" >> xxx
echo "FAKE 1" >> xxx

for (( j=0;j<$PART;j++)); do
    for (( i=1;i<=15;i++)); do
         #skip header 1 line
         start=$(echo "scale=10; $j * 16 + $i + 1 ;" | bc)
         echo $start
    done
    read var1 var2 junk << !
    $(sed -n '2p' fit_par.dat)
    !
    echo $var1 $var2
done



---------- Post updated at 07:23 AM ---------- Previous update was at 07:20 AM ----------
Quote:
Originally Posted by Scrutinizer
Code:
sed -n '2p' file.dat | read var1 var2
echo $var1 $var2

will work as you would expect in ksh, but not in the other shells.

Otherwise, alternatives to Scottn' s solution :
Code:
sed -n '2p' file.dat | { read var1 var2
echo $var1 $var2 ;}

-or if your platform supports it
Code:
read var1 var2 < <(sed -n '2p' file.dat)
echo $var1 $var2

-or if your shell supports it:
Code:
read var1 var2 <<< $(sed -n '2p' file.dat)
echo $var1 $var2

The latter is small variation to scottn's code and work in bash and ksh93
I chose the last one
Thank you all
 
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