#!/bin/sh -u
#  $0  (no args)
# A script that loops concatenating a string over and over until
# the length of the output string is larger than a desired length.
#
# Some of the comments in this script are "teacher" comments that should
# never appear in student programs (or real-world programs).
#
# -IAN! idallen@ncf.ca  February 2002

export PATH=/bin:/usr/bin
umask 022

# The string to repeat (quoted to include the blanks).
# The desired length of the output, in characters.
#
string='Hello World! '
length=100

# Use command substitution to get the current length of the string.
# The "wc" command is reading stdin, which is the output of the "echo".
# The output of "wc" (the number) is substituted into the line.
# The "test" command (named "[") tests the number against the length.
# The return code of "test" determines whether the "while" keeps going.
#
out=''  # start with an empty output string
while [ $(echo "$out" | wc -c) -lt $length ]; do
	echo "The current length is $(echo "$out" | wc -c)"
	out="$out$string"
	echo "The new length is $(echo "$out" | wc -c)"
done
echo "The output string is:"
echo "$out"
echo "The length of the output string is: $(echo "$out" | wc -c)"

exit 0