reading variable value from a file

Shell Programming and Scripting
1

Hello,

I need to read a variable value from script.
Below is the scenario

I am reading a value from an external file say a.txt

a.txt:

Jan
Feb
Mar

I need the corresponding value of the months in in numerics such as Jan -->1,
Feb-->2 etc.

I have this mapping in another file b.txt as

Jan=01
Feb=02
Mar=03

I am reading the text from a.txt, but since i need the numeric values,
I am trying to read the values of these months from b.txt

Plz let me know a possible way out

Thanks a lot!!

2

Code:-

nawk -F"(=| )" '
(FNR==NR){a[$1]=$2 ; next}
{r=($1 in a) ?  $1"-->"a[$1] :  $1 ; print r}
' b.txt a.txt

BR