3 Like the unix `which` utility.
5 Finds the first instance of a specified executable in the PATH
6 environment variable. Does not cache the results, so `hash -r` is not
7 needed when the PATH changes.
12 var which = require('which')
15 which('node', function (er, resolvedPath) {
16 // er is returned if no "node" is found on the PATH
17 // if it is found, then the absolute path to the exec is returned
21 which('node').then(resolvedPath => { ... }).catch(er => { ... not found ... })
24 // throws if not found
25 var resolved = which.sync('node')
27 // if nothrow option is used, returns null if not found
28 resolved = which.sync('node', {nothrow: true})
30 // Pass options to override the PATH and PATHEXT environment vars.
31 which('node', { path: someOtherPath }, function (er, resolved) {
34 console.log('found at %j', resolved)
40 Same as the BSD `which(1)` binary.
43 usage: which [-as] program ...
48 You may pass an options object as the second argument.
50 - `path`: Use instead of the `PATH` environment variable.
51 - `pathExt`: Use instead of the `PATHEXT` environment variable.
52 - `all`: Return all matches, instead of just the first one. Note that
53 this means the function returns an array of strings instead of a