bash_variables_two

#!/usr/bin/env bash

VAR_ONE="value\n"    #
VAR_TWO='value\n'
VAR_THREE=value\\n

# command output can be piped to an inline string,
# just like a declared variable using $( ... )

# this line will inject the output of the printf command into the string.
echo This is VAR_ONE: $( printf $VAR_ONE ), VAR_TWO: $( printf $VAR_TWO ), VAR_THREE: $( printf $VAR_THREE )


echo  # -------------------------------


# the output can also be assigned to another variable.
BASH_BIN=$( which bash )

# the which command returns the whole path for the given executable.
echo the bash binary is located at $BASH_BIN
echo the bash binary is located at $( which bash )  # same output as above.

# you can even embed a command inside of another command.
echo the bash binary is located at $( dirname $( which bash ) )


echo  # -------------------------------


# Mathematical calculations can be performed as well using
# the $(( ... )) wrappers. Note that arbitrary spaces can be
# added within the parentheses.
NUMBER_TWO=$(( 1 + 1 ))                         # addition
NUMBER_SIX=$(( $NUMBER_TWO * 3 ))               # multiplication
NUMBER_THREE=$(( $NUMBER_SIX / 2 ))             # division
NUMBER_FOUR=$(( $NUMBER_SIX - $NUMBER_TWO ))    # subtraction
NUMBER_ONE=$(( $NUMBER_FOUR % $NUMBER_THREE ))  # modulo

echo The Number Two: $NUMBER_TWO
echo The Number Six: $NUMBER_SIX
echo The Number Three: $NUMBER_THREE
echo The Number Four: $NUMBER_FOUR
echo The Number One: $NUMBER_ONE

# Note that Bash cannot perform floating point calculations
# natively. It is limited to only integer calculations.