Example 5-2. Plain Variable Assignment

#!/bin/bash

echo

# When is a variable "naked", i.e., lacking the '$' in front?
# When it is being assigned, rather than referenced.

# Assignment
a=879
echo "The value of "a" is $a"

# Assignment using 'let'
let a=16+5
echo "The value of "a" is now $a"

echo

# In a 'for' loop (really, a type of disguised assignment)
echo -n "The values of "a" in the loop are "
for a in 7 8 9 11
do
  echo -n "$a "
done

echo
echo

# In a 'read' statement (also a type of assignment)
echo -n "Enter "a" "
read a
echo "The value of "a" is now $a"

echo

exit 0

Example 5-3. Variable Assignment, plain and fancy

#!/bin/bash

a=23              # Simple case
echo $a
b=$a
echo $b

# Now, getting a little bit fancier...

a=`echo Hello!`   # Assigns result of 'echo' command to 'a'
echo $a

a=`ls -l`         # Assigns result of 'ls -l' command to 'a'
echo $a

exit 0

Variable assignment using the $(...) mechanism (a newer method than backquotes)

# From /etc/rc.d/rc.local
R=$(cat /etc/redhat-release)
arch=$(uname -m)

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