while statement

C-style while loop:

#!/bin/bash
# wh-loopc.sh: Count to 10 in a "while" loop.
LIMIT=10
a=1
while [ "$a" -le $LIMIT ]
do
echo -n "$a "
let "a+=1"
done           # No surprises, so far.
echo; echo
# +=================================================================+

# Now, repeat with C-like syntax.

# Double parentheses permit space when setting a variable, as in C.
((a = 1))      # a=1

# Double parentheses, and no "$" preceding variables.
while (( a <= LIMIT ))
do 
echo -n "$a "  
((a += 1))
# Double parentheses permit incrementing a variable with C-like syntax.
done
exit 0

# +=================================================================+
# reading a file line by line

while read line 
do 
echo "${line}"
done < ./straddle.prop