diff --git a/src/main.cpp b/src/main.cpp
index f411ac0..da332a7 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -10,12 +10,13 @@
 #include <cstring>
 #include <limits.h>
 #include <fstream>
+#include <signal.h>
 
 using namespace std;
 
-vector<string> builtInFunctions = {"exit", "cd", "sub"};
+vector<string> functions = {"exit", "cd", "sub", "listsubs", "set", "get", "run"};
 
-vector<pair<string, vector<string>>> substitutions = {{"ls", {"ls", "--color"}}};
+vector<pair<string, vector<string>>> substitutions;
 
 void log(string input) {
     cout << input << endl;
@@ -43,9 +44,30 @@ string prompt() {
     return input;
 }
 
+vector<string> getPath() {
+    string pathstr = getenv("PATH");
+    if (pathstr == "") {
+        log("WARNING! SPACE CANNOT FIND THE PATH! Please ensure your path is set as an environment variable in your Spacefile, or one of Space's parents has set the PATH environment variable. For now, enjoy the default path :)");
+    } else {
+        vector<string> path;
+        string buffer;
+        for (int i = 0; i < pathstr.size(); i++) {
+            if (pathstr[i] == ':') {
+                path.push_back(buffer);
+                buffer = "";
+            } else {
+                buffer += pathstr[i];
+            }
+        }
+        path.push_back(buffer);
+        return path;
+    }
+    return {"/bin", "/usr/bin", "/usr/local/bin"}; 
+}
+
 string findExecutable(string executable) {
-    for (int i = 0; i < builtInFunctions.size(); i++) {
-        if (builtInFunctions[i] == executable) {
+    for (int i = 0; i < functions.size(); i++) {
+        if (functions[i] == executable) {
             return executable;
         }
     }
@@ -56,7 +78,7 @@ string findExecutable(string executable) {
         return executable;
     }
     string output;
-    vector<string> path = {"/bin", "/usr/bin", "/usr/local/bin"};
+    vector<string> path = getPath();
     for (int i = 0; i < path.size(); i++) {
         output = path[i] + "/" + executable;
         if (filesystem::exists(output)) {
@@ -139,30 +161,91 @@ vector<string> tokeniseSubstitutions(string input) {
 }
 
 int runProcess(vector<string> args) {
-    pid_t pid = fork();
-    if (pid == -1) {
-        cerr << "Fork failed!" << endl;
-        return -1;
-    }
-    if (pid == 0) {
-        vector<char*> cargs;
-        cargs.push_back(const_cast<char*>(args[0].c_str()));        
-        for (int i = 1; i < args.size(); i++) {
-            cargs.push_back(const_cast<char*>(args[i].c_str()));        
+    if (args[0] == "exit") {
+        exit(0);
+    } else if (args[0] == "cd") {
+        if (args.size() == 1) {
+            log("cd requires an argument");
+            return 1;
+        } else {
+            filesystem::current_path(args[1]);
         }
-        cargs.push_back(nullptr);
-        execvp(args[0].c_str(), cargs.data());
-        
-        cerr << "Execution failed with error " << strerror(errno) << endl;
-        _exit(1);
-    }
-    int status;
-    waitpid(pid, &status, 0);
+    } else if (args[0] == "set") {
+        if (args.size() < 3) {
+            log("set requires 2 arguments");
+            return 1;
+        }
+        string envStr = (args[1] + "=" + args[2]);
+        char* cEnvStr = strdup(envStr.c_str());
+        putenv(cEnvStr);
+    } else if (args[0] == "get") {
+        if (args.size() < 2) {
+            log("get requires an argument");
+            return 1;
+        }
+        char* value = getenv(args[1].c_str());
+        if (value == nullptr) {
+            log("Environment variable " + args[1] + " not found");
+            return 1;
+        }
+        cout << value << endl;
+    } else if (args[0] == "sub") {
+        if (args.size() < 3) {
+            log("substitute requires 2 arguments");
+            return 1;
+        }
+        vector<string> subArgs = tokeniseSubstitutions(args[2]);
+        substitutions.push_back({args[1], subArgs});
+    } else if (args[0] == "listsubs") {
+        log("Substitutions:");
+        for (int i = 0; i < substitutions.size(); i++) {
+            string substring;
+            for (int j = 0; j < substitutions[i].second.size(); j++) {
+                substring += substitutions[i].second[j] + " ";
+            }
+            cout << substitutions[i].first << " -> " << substring << endl;
+        }
+    } else {
+        pid_t pid = fork();
+        if (pid == -1) {
+            cerr << "Fork failed!" << endl;
+            return -1;
+        }
+        if (pid == 0) {
+            vector<char*> cargs;
+            cargs.push_back(const_cast<char*>(args[0].c_str()));        
+            for (int i = 1; i < args.size(); i++) {
+                cargs.push_back(const_cast<char*>(args[i].c_str()));        
+            }
+            cargs.push_back(nullptr);
+            execvp(args[0].c_str(), cargs.data());
+            
+            cerr << "Execution failed with error " << strerror(errno) << endl;
+            _exit(1);
+        }
+        int status;
+        waitpid(pid, &status, 0);
 
-    if (WIFEXITED(status)) {
-        return WEXITSTATUS(status);
+        if (WIFEXITED(status)) {
+            return WEXITSTATUS(status);
+        }
+        return -1; 
     }
-    return -1;
+    return 0;
+}
+
+void runScript(string script) {
+    string scriptLine;
+    ifstream scriptFile(script);
+    while (getline(scriptFile, scriptLine)) {
+        vector<string> tokens = tokenise(scriptLine);
+        if (tokens.empty()) continue;
+        int returnCode = runProcess(tokens);
+        if (returnCode != 0) {
+            log("Script error:\nCommand " + tokens[0] + " failed with exit code " + to_string(returnCode));
+        }
+    }
+    scriptFile.close();
 }
 
 void doStartup() {
@@ -186,7 +269,13 @@ void doStartup() {
     }
 }
 
+void handler(int signum);
+
 int main(int argc, char *argv[]) {
+    signal(SIGINT, handler);
+    if (argc > 1) {
+        runScript(argv[2]);
+    }
     doStartup();
     bool continueLoop = true;
     while (continueLoop) {
@@ -196,33 +285,6 @@ int main(int argc, char *argv[]) {
         }
         vector<string> tokens = tokenise(input);
         auto path = filesystem::current_path();
-        if (tokens[0] == "exit") {
-            exit(0);
-        } else if (tokens[0] == "cd") {
-            if (tokens.size() == 1) {
-                log("cd requires an argument");
-            } else {
-                filesystem::current_path(tokens[1]);
-            }
-            continue;
-        } else if (tokens[0] == "sub") {
-            if (tokens.size() < 3) {
-                log("substitute requires 2 arguments");
-                continue;
-            }
-            vector<string> args = tokeniseSubstitutions(tokens[2]);
-            substitutions.push_back({tokens[1], args});
-            continue;
-        } else if (tokens[0] == "listsubs") {
-            log("Substitutions:");
-            for (int i = 0; i < substitutions.size(); i++) {
-                string substring;
-                for (int j = 0; j < substitutions[i].second.size(); j++) {
-                    substring += substitutions[i].second[j] + " ";
-                }
-                cout << substitutions[i].first << " -> " << substring << endl;
-            }
-        }
         if (tokens.empty()) {
             continue;
         }
@@ -233,3 +295,7 @@ int main(int argc, char *argv[]) {
     }
     return 0;
 }
+
+void handler(int signum) {
+    main(1, nullptr);
+}