Hi, I'm trying to run loops in shell scripts using the following script. loop=1 while [ loop -lt 10 ] do echo 'this is my $loop text-line' loop='expr $loop + 1' done ---- but I'm getting error: test: unknown parameter $loop when I change ' by " in the above expr statement, I get the error: test: unknown parameter 0 I need urgent help for this script. please mail your responses to: mdp02ab@sheffield.ac.uk thanks in advance. cheers, amit.

while [ $loop -lt 10 ] ; do echo "this is my $loop text-line" loop=`expr $loop + 1` done you need a "$" before the variable. expressions with variables need double quotes use the back-tick character instead of a single quote for evaluation.

Or in Korn shell: #!/bin/ksh integer i=0 limit=10 while (( i limit )) && (( i += 1 )) do     print "This is iteration ${i}" done

As usual forgot to quote the less-than sign in posting. That should have been: #!/bin/ksh integer i=0 limit=10 while (( i < limit )) && (( i += 1 )) do print "This is iteration ${i}" done

Or as I've recently discovered, the even more concise: #!/bin/ksh integer i=0 limit=10 while (( i++ < limit )) do     print "This is iteration ${i}" done