ksh声明变量、条件判断、数值计算

#!/bin/ksh
# Program name: numberit
# Put line numbers on all lines of memo
if (( $# < 1 ))
then
 print "Usage: $0 filename " >&2
 exit 1
fi
integer count=1              # Initialize count
cat $1 | while read line     # Input is coming from memo
do
  (( count == 1 )) && print "Processing file $1..." > /dev/tty
   print $count $line
  (( count+=1 ))
done > tmp$$                 # Output is going to a temporary file
mv tmp$$ $1