Shell Programming and Scripting

a,12,45,bn,c
a,16,46,bn1,c
a,18,47,bn2,c
a,12,47,bn3,c
a,11,49,bn4,c

awk 'NR%2' file

#! /bin/ksh
set -x
set -A abc `cat test1.dat`
n=`wc -l test1.dat`
while [[ $i -lt $n ]]
do
for(i=0;i<=n;i+=1)
do
echo ${abc[i]}  < test2.dat
done
i=`expr $i + 1`
done

 syntax error at line 8 : `(' unexpected

$
$ cat -n f1
     1  a,12,45,bn,c
     2  a,16,46,bn1,c
     3  a,18,47,bn2,c
     4  a,12,47,bn3,c
     5  a,11,49,bn4,c
     6  a,19,79,bn8,c
$
$
$ ##
$ perl -lne 'chomp;
>            if ($.%2 == 0) {
>              $b = $.;
>              push @x,$_;
>              print "The pair of lines is now stored as first two elements of \@x";
>              foreach $i (@x) {print "\t==> ",$i};
>              print "Perform the calculations, print to file and reset the array";
>              ## some calculations here...
>              $file = "myfile_".$a."_".$b;
>              print "Now writing to file: $file ";
>              open (F, "> $file") or die "Cannot open $file for writing: $!";
>              foreach $i (@x) {print F "\t==> ",$i};
>              close (F) or die "Cannot close $file: $!";
>              print "-"x60;
>              @x=()}
>            else { push @x,$_; $a=$. }' f1
The pair of lines is now stored as first two elements of @x
        ==> a,12,45,bn,c
        ==> a,16,46,bn1,c
Perform the calculations, print to file and reset the array
Now writing to file: myfile_1_2
------------------------------------------------------------
The pair of lines is now stored as first two elements of @x
        ==> a,18,47,bn2,c
        ==> a,12,47,bn3,c
Perform the calculations, print to file and reset the array
Now writing to file: myfile_3_4
------------------------------------------------------------
The pair of lines is now stored as first two elements of @x
        ==> a,11,49,bn4,c
        ==> a,19,79,bn8,c
Perform the calculations, print to file and reset the array
Now writing to file: myfile_5_6
------------------------------------------------------------
$
$ cat myfile_1_2
        ==> a,12,45,bn,c
        ==> a,16,46,bn1,c
$
$ cat myfile_3_4
        ==> a,18,47,bn2,c
        ==> a,12,47,bn3,c
$
$ cat myfile_5_6
        ==> a,11,49,bn4,c
        ==> a,19,79,bn8,c
$
$