Shell Programming and Scripting

 abc|def|ghi|jkl|mno|pqr|stu|vwx|yz

abc|def|ghi|j
kl|mno|pqr|s
tu|vwx|yz

 print 'abc|def|ghi|jkl|mno|pqr|stu|vbbwx|yz' |  perl -pe's/(\|)/++$c%3?$1:"$1\n"/ge'

abc|def|ghi|
jkl|mno|pqr|
stu|vbbwx|yz

echo "abc|def|ghi|jkl|mno|pqr|stu|vwx|yz" | perl -e 'chomp($x=<>); $x =~ s/(.*?\|.*?\|.*?\|.)/$1\n/g; print $x'

echo 'abc|def|ghi|jkl|mno|pqr|stu|vbbwx|yz' |  perl -pe 's/(.*?\|.)/++$c%3?$1:"$1\n"/ge'

my $str='abc|def|ghi|jkl|mno|pqr|stu|vwx|yz';
$str =~ s/([|](?{$cnt++}).)/($cnt%3==0)?$1."\n":$1/eg;
print $str,"\n";

echo "abc|def|ghi|jkl|mno|pqr|stu|vwx|yz" | 
awk -vFS=''  '{ 
 for(i=1;i<=NF;i++) 
 {   
   if(j==3)
   { 
       $i=$i"\n";j=0;
   } 
   printf("%s", $i); 
   if($i=="|") 
   {
     j++
   }  
 }  
              }
END{ print "\n"}  '

$ echo 'abc|def|ghi|jkl|mno|pqr|stu|vbbwx|yz' |  perl -pe's/((?:[^|]*\|){3}\w)/$1\n/g'
abc|def|ghi|j
kl|mno|pqr|s
tu|vbbwx|yz