“which in ruby”: Checking if program exists in $PATH from ruby

Question

my scripts rely heavily on external programs and scripts. I need to be sure that a program I need to call exists. Manually, I\'d check this using \'which\' in the commandlin

Answer 1

for jruby, any of the solutions that depend on mkmf may not work, as it has a C extension.

for jruby, the following is an easy way to check if something is executable on the path:

main » unix_process = java.lang.Runtime.getRuntime().exec("git status")
=> #
main » unix_process.exitValue()
=> 0
main »

if the executable isn't there, it will raise a runtime error, so you may want to do this in a try/catch block in your actual usage.