Conditional settings in Vim whether command is in system path

Question

How do I make conditional settings in vim based on whether some command is available in system path?

For example I would like to enable par paragraph formating when the par command is available

Something like this:

if syspathhas("par")
    set formatprg=par\ -w80
endif

Answer 1

Use the executable function, as

if executable("par")
    set formatprg=par\ -w80
endif