I already wrote a post about adopting a functional programming style in Bash scripts. Here I want to explore how to build a minimal, reusable functional toolbox for my bash scripts, avoiding redefinition of base functional bricks whenever I need them.
So, in short: I wish I could write a scripts (say
use-functional-bricks.sh) like the following
referring to “globally” available functions
reduce(and maybe others, too) without to re-write them everywhere they are needed and without to be bound to external scripts invocation.
The way I think we can solve the problem refers to three interesting features available in bash:
- export functions from scripts (through
- execute scripts in the current shell’s environment, through
- execute scripts when bash starts
So I wrote the following script (say
and added the following line at the end of my user’s
and… voila!: now
reduce implemented in
functional-bricks.sh are available in all my bash sessions - so I can use them in all my scripts!
And because seeing is beleiving… if I launch the script
use-functional-bricks.shdefined above, I get the following output: