Syntax

The syntax is:

printf "%'.2f" var

OR

printf "%'.2d" var

OR

printf "Total Rs.%'.2f" var

OR

printf "Total $.%'.2f" var

The ' act as a field and printing modifiers for decimal conversions, the thousands grouping separator is applied to the integer portion of the output according to the current LC_NUMERIC. Run the locale program to check current settings for LC_NUMERIC:

locale

Sample outputs:

LANG=en_IN
LANGUAGE=en_IN:en
LC_CTYPE="en_IN"
LC_NUMERIC="en_IN"
LC_TIME="en_IN"
LC_COLLATE="en_IN"
LC_MONETARY="en_IN"
LC_MESSAGES="en_IN"
LC_PAPER="en_IN"
LC_NAME="en_IN"
LC_ADDRESS="en_IN"
LC_TELEPHONE="en_IN"
LC_MEASUREMENT="en_IN"
LC_IDENTIFICATION="en_IN"
LC_ALL=

I’ve setup LC_ALL and LANG as follows in bash. You need to put the following lines in your ~/.bashrc and/or ~/.profile files:

export LC_ALL=en_IN.UTF-8
export LANG=en_IN.UTF-8
export LANGUAGE=en_IN.UTF-8

Examples

Type the following commands:

x="240570.578"
printf "%'.2f\n" $x
printf "Total $%'.2f\n" $x
printf "Total INR.%'.2f\n" $x

Sample outputs:

2,40,570.58
Total $2,40,570.58
Total INR.2,40,570.58

Recommended readings

man printf
man 3 printf
man local