How to convert floating point numbers in fortran format to decimals using shell (bash) tools?

Question

How to most easily convert floating point numbers to decimals using shell (bash) tools? For example: I have 0.17879D-13 as input and want 0.000000000000017879 as output. I have tried awk and bc but couldn't succeed.

Answer 1

Now I got something. I use sed to replace "D" by "e" then awk can process it, eg:

echo 0.17879D-13 | sed s/D/e/g | awk '{printf("%.20f\\n",$1)}'