README.md (1352B)
1 # which 2 3 Like the unix `which` utility. 4 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. 8 9 ## USAGE 10 11 ```javascript 12 var which = require('which') 13 14 // async usage 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 18 }) 19 20 // or promise 21 which('node').then(resolvedPath => { ... }).catch(er => { ... not found ... }) 22 23 // sync usage 24 // throws if not found 25 var resolved = which.sync('node') 26 27 // if nothrow option is used, returns null if not found 28 resolved = which.sync('node', {nothrow: true}) 29 30 // Pass options to override the PATH and PATHEXT environment vars. 31 which('node', { path: someOtherPath }, function (er, resolved) { 32 if (er) 33 throw er 34 console.log('found at %j', resolved) 35 }) 36 ``` 37 38 ## CLI USAGE 39 40 Same as the BSD `which(1)` binary. 41 42 ``` 43 usage: which [-as] program ... 44 ``` 45 46 ## OPTIONS 47 48 You may pass an options object as the second argument. 49 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 54 single string.