A resource agent may need to test for the availability of a specific executable. The have_binary convenience function comes in handy here:

if ! have_binary frobnicate; then
   ocf_log warn "Missing frobnicate binary, frobnication disabled!"
fi

If a missing binary is a fatal problem for the resource, then the check_binary function should be used:

check_binary frobnicate

Using check_binary is a shorthand method for testing for the existence (and executability) of the specified binary, and exiting with $OCF_ERR_INSTALLED if it cannot be found or executed.

	Note
	Both have_binary and check_binary honor $PATH when the binary to test for is not specified as a full path. It is usually wise to not test for a full path, as binary installations path may vary by distribution or user policy.