diff --git a/dist/smartshell.plugins.d.ts b/dist/smartshell.plugins.d.ts
index 65b306a..1a2252f 100644
--- a/dist/smartshell.plugins.d.ts
+++ b/dist/smartshell.plugins.d.ts
@@ -1,3 +1,4 @@
 import * as shelljs from 'shelljs';
 import * as smartq from 'smartq';
-export { shelljs, smartq };
+import * as which from 'which';
+export { shelljs, smartq, which };
diff --git a/dist/smartshell.plugins.js b/dist/smartshell.plugins.js
index ba06315..72960ef 100644
--- a/dist/smartshell.plugins.js
+++ b/dist/smartshell.plugins.js
@@ -4,4 +4,6 @@ const shelljs = require("shelljs");
 exports.shelljs = shelljs;
 const smartq = require("smartq");
 exports.smartq = smartq;
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoic21hcnRzaGVsbC5wbHVnaW5zLmpzIiwic291cmNlUm9vdCI6IiIsInNvdXJjZXMiOlsiLi4vdHMvc21hcnRzaGVsbC5wbHVnaW5zLnRzIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiI7O0FBQUEsbUNBQWtDO0FBSWhDLDBCQUFPO0FBSFQsaUNBQWdDO0FBSTlCLHdCQUFNIn0=
\ No newline at end of file
+const which = require("which");
+exports.which = which;
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoic21hcnRzaGVsbC5wbHVnaW5zLmpzIiwic291cmNlUm9vdCI6IiIsInNvdXJjZXMiOlsiLi4vdHMvc21hcnRzaGVsbC5wbHVnaW5zLnRzIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiI7O0FBQUEsbUNBQWtDO0FBS2hDLDBCQUFPO0FBSlQsaUNBQWdDO0FBSzlCLHdCQUFNO0FBSlIsK0JBQThCO0FBSzVCLHNCQUFLIn0=
\ No newline at end of file
diff --git a/dist/smartshell.wrap.d.ts b/dist/smartshell.wrap.d.ts
index 1ee0de8..15edf81 100644
--- a/dist/smartshell.wrap.d.ts
+++ b/dist/smartshell.wrap.d.ts
@@ -1,9 +1,15 @@
 /// <reference types="node" />
 import { ChildProcess } from 'child_process';
+/**
+ * interface for ExecResult
+ */
 export interface IExecResult {
     exitCode: number;
     stdout: string;
 }
+/**
+ * interface for streaming ExecResult
+ */
 export interface IExecResultStreaming {
     childProcess: ChildProcess;
     finalPromise: Promise<IExecResult>;
@@ -25,3 +31,7 @@ export declare let execStreaming: (commandStringArg: string) => {
     childProcess: ChildProcess;
     finalPromise: Promise<IExecResult>;
 };
+/**
+ * get a path
+ */
+export declare let which: (cmd: string) => Promise<string>;
diff --git a/dist/smartshell.wrap.js b/dist/smartshell.wrap.js
index 56a9711..78a6e41 100644
--- a/dist/smartshell.wrap.js
+++ b/dist/smartshell.wrap.js
@@ -45,4 +45,17 @@ exports.execStreaming = (commandStringArg) => {
         finalPromise: childProcessEnded.promise
     };
 };
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoic21hcnRzaGVsbC53cmFwLmpzIiwic291cmNlUm9vdCI6IiIsInNvdXJjZXMiOlsiLi4vdHMvc21hcnRzaGVsbC53cmFwLnRzIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiI7O0FBQUEsZ0RBQStDO0FBZ0IvQzs7O0dBR0c7QUFDUSxRQUFBLElBQUksR0FBRyxDQUFDLGdCQUF3QjtJQUN6QyxJQUFJLElBQUksR0FBRyxPQUFPLENBQUMsTUFBTSxDQUFDLEtBQUssRUFBZSxDQUFBO0lBQzlDLE9BQU8sQ0FBQyxPQUFPLENBQUMsSUFBSSxDQUFDLGdCQUFnQixFQUFFLEVBQUUsS0FBSyxFQUFFLElBQUksRUFBRSxFQUFFLENBQUMsSUFBSSxFQUFFLE1BQU0sRUFBRSxNQUFNO1FBQzNFLElBQUksQ0FBQyxPQUFPLENBQUM7WUFDWCxRQUFRLEVBQUUsSUFBSTtZQUNkLE1BQU0sRUFBRSxNQUFNO1NBQ2YsQ0FBQyxDQUFBO0lBQ0osQ0FBQyxDQUFDLENBQUE7SUFDRixNQUFNLENBQUMsSUFBSSxDQUFDLE9BQU8sQ0FBQTtBQUNyQixDQUFDLENBQUE7QUFFRDs7O0dBR0c7QUFDUSxRQUFBLFVBQVUsR0FBRyxDQUFDLGdCQUF3QjtJQUMvQyxJQUFJLElBQUksR0FBRyxPQUFPLENBQUMsTUFBTSxDQUFDLEtBQUssRUFBZSxDQUFBO0lBQzlDLE9BQU8sQ0FBQyxPQUFPLENBQUMsSUFBSSxDQUFDLGdCQUFnQixFQUFFLEVBQUUsS0FBSyxFQUFFLElBQUksRUFBRSxNQUFNLEVBQUUsSUFBSSxFQUFFLEVBQUUsQ0FBQyxJQUFJLEVBQUUsTUFBTSxFQUFFLE1BQU07UUFDekYsSUFBSSxDQUFDLE9BQU8sQ0FBQztZQUNYLFFBQVEsRUFBRSxJQUFJO1lBQ2QsTUFBTSxFQUFFLE1BQU07U0FDZixDQUFDLENBQUE7SUFDSixDQUFDLENBQUMsQ0FBQTtJQUNGLE1BQU0sQ0FBQyxJQUFJLENBQUMsT0FBTyxDQUFBO0FBQ3JCLENBQUMsQ0FBQTtBQUVEOztHQUVHO0FBQ1EsUUFBQSxhQUFhLEdBQUcsQ0FBQyxnQkFBd0I7SUFDbEQsSUFBSSxpQkFBaUIsR0FBRyxPQUFPLENBQUMsTUFBTSxDQUFDLEtBQUssRUFBZSxDQUFBO0lBQzNELElBQUksZ0JBQWdCLEdBQUcsT0FBTyxDQUFDLE9BQU8sQ0FBQyxJQUFJLENBQUMsZ0JBQWdCLEVBQUUsRUFBQyxLQUFLLEVBQUUsSUFBSSxFQUFFLE1BQU0sRUFBRSxJQUFJLEVBQUMsRUFBRSxDQUFDLElBQUksRUFBRSxNQUFNLEVBQUUsTUFBTTtRQUM5RyxpQkFBaUIsQ0FBQyxPQUFPLENBQUM7WUFDeEIsUUFBUSxFQUFFLElBQUk7WUFDZCxNQUFNLEVBQUUsTUFBTTtTQUNmLENBQUMsQ0FBQTtJQUNKLENBQUMsQ0FBQyxDQUFBO0lBQ0YsTUFBTSxDQUFDO1FBQ0wsWUFBWSxFQUFFLGdCQUFnQjtRQUM5QixZQUFZLEVBQUUsaUJBQWlCLENBQUMsT0FBTztLQUN4QyxDQUFBO0FBQ0gsQ0FBQyxDQUFBIn0=
\ No newline at end of file
+/**
+ * get a path
+ */
+exports.which = (cmd) => {
+    let done = plugins.smartq.defer();
+    plugins.which(cmd, (err, path) => {
+        if (err) {
+            done.reject(err);
+        }
+        done.resolve(path);
+    });
+    return done.promise;
+};
+//# sourceMappingURL=data:application/json;base64,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
\ No newline at end of file
diff --git a/package.json b/package.json
index be6eb7d..be7b93a 100644
--- a/package.json
+++ b/package.json
@@ -27,7 +27,9 @@
   },
   "dependencies": {
     "@types/shelljs": "^0.6.0",
+    "@types/which": "^1.0.28",
     "shelljs": "^0.7.6",
-    "smartq": "^1.1.0"
+    "smartq": "^1.1.0",
+    "which": "^1.2.12"
   }
 }
diff --git a/ts/smartshell.plugins.ts b/ts/smartshell.plugins.ts
index 075d172..1bf78a3 100644
--- a/ts/smartshell.plugins.ts
+++ b/ts/smartshell.plugins.ts
@@ -1,7 +1,9 @@
 import * as shelljs from 'shelljs'
 import * as smartq from 'smartq'
+import * as which from 'which'
 
 export {
   shelljs,
-  smartq
-}
\ No newline at end of file
+  smartq,
+  which
+}
diff --git a/ts/smartshell.wrap.ts b/ts/smartshell.wrap.ts
index 2ef5d6c..a7b5449 100644
--- a/ts/smartshell.wrap.ts
+++ b/ts/smartshell.wrap.ts
@@ -4,11 +4,17 @@ import * as plugins from './smartshell.plugins'
 import { ChildProcess } from 'child_process'
 import { Deferred } from 'smartq'
 
+/**
+ * interface for ExecResult
+ */
 export interface IExecResult {
   exitCode: number,
   stdout: string
 }
 
+/**
+ * interface for streaming ExecResult
+ */
 export interface IExecResultStreaming {
   childProcess: ChildProcess,
   finalPromise: Promise<IExecResult>
@@ -60,3 +66,17 @@ export let execStreaming = (commandStringArg: string) => {
     finalPromise: childProcessEnded.promise
   }
 }
+
+/**
+ * get a path
+ */
+export let which = (cmd: string): Promise<string> => {
+  let done = plugins.smartq.defer()
+  plugins.which(cmd, (err, path: string) => {
+    if (err) {
+      done.reject(err)
+    }
+    done.resolve(path)
+  })
+  return done.promise
+}
diff --git a/yarn.lock b/yarn.lock
index 11bda29..7c23e83 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -37,6 +37,10 @@
   dependencies:
     "@types/node" "*"
 
+"@types/which@^1.0.28":
+  version "1.0.28"
+  resolved "https://registry.yarnpkg.com/@types/which/-/which-1.0.28.tgz#016e387629b8817bed653fe32eab5d11279c8df6"
+
 assertion-error@^1.0.1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/assertion-error/-/assertion-error-1.0.2.tgz#13ca515d86206da0bac66e834dd397d87581094c"
@@ -114,6 +118,10 @@ interpret@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/interpret/-/interpret-1.0.1.tgz#d579fb7f693b858004947af39fa0db49f795602c"
 
+isexe@^1.1.1:
+  version "1.1.2"
+  resolved "https://registry.yarnpkg.com/isexe/-/isexe-1.1.2.tgz#36f3e22e60750920f5e7241a476a8c6a42275ad0"
+
 minimatch@^3.0.2:
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/minimatch/-/minimatch-3.0.3.tgz#2a4e4090b96b2db06a9d7df01055a62a77c9b774"
@@ -202,6 +210,12 @@ typings-test@^1.0.3:
     "@types/mocha" "^2.2.31"
     typings-global "*"
 
+which@^1.2.12:
+  version "1.2.12"
+  resolved "https://registry.yarnpkg.com/which/-/which-1.2.12.tgz#de67b5e450269f194909ef23ece4ebe416fa1192"
+  dependencies:
+    isexe "^1.1.1"
+
 wrappy@1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/wrappy/-/wrappy-1.0.2.tgz#b5243d8f3ec1aa35f1364605bc0d1036e30ab69f"