Zero fill a string

Shell Programming and Scripting
1

How do I zero fill a string. E.g pad a string to two digits

m=`date "+%m"`
pm=`expr $m - 1`
echo $pm

the above code echoes 1. I want it to echo 01. Any ideas?

2 
printf '%02d' $pm
3

In Korn Shell

$ cat zerofill.ksh
#!/bin/ksh

m=`date "+%m"`
pm=`expr $m - 1`
echo $pm
typeset -Z2 ZERO_FILLED_NEXT_DAY=$pm
echo "ZERO_FILLED_NEXT_DAY=$ZERO_FILLED_NEXT_DAY"

exit 0

$ ./zerofill.ksh
1
ZERO_FILLED_NEXT_DAY=01
4

Thanks :smiley: