Load script arguments into `args` list

For example, running "./do_math.pl 5 + 5" would define args as a list of
( /usr/bin/pl ./do_math.pl 5 + 5 ), where each of the five elements is a
string object. The arguments will also be loaded when opening the repl,
but NOT when writing  pl code directly as command-line arguments (i.e.
'./pl "(* 9 9)"').

src/pebblisp.c

@@ -756,11 +756,7 @@ Object parseEval(const char *input, struct Environment *env)
 }
 
 #ifdef STANDALONE
-int readFile(const char *filename, struct Environment *env) {
-    FILE *input = fopen(filename, "r");
-    if(!input) {
-        return 1;
-    }
+int _readFile(FILE *input, struct Environment *env) {
     Object r = numberObject(0);
     char page[4096] = "";
     const unsigned LINE_MAX = 256;
@@ -797,6 +793,14 @@ int readFile(const char *filename, struct Environment *env) {
     fclose(input);
     return 0;
 }
+int readFile(const char *filename, struct Environment *env) {
+    FILE *input = fopen(filename, "r");
+    if(!input) {
+        return 1;
+    }
+    _readFile(input, env);
+    return 0;
+}
 
 Object loadFile(Object filename, Object _, struct Environment *env) {
     if (isStringy(filename)) {
@@ -806,20 +810,33 @@ Object loadFile(Object filename, Object _, struct Environment *env) {
     return numberObject(1);
 }
 
-void repl(struct Environment *env)
-{
+void repl(struct Environment *env) {
     if (readFile(SCRIPTDIR "/repl.pbl", env) == 1) {
         fprintf(stderr, "Could not read '%s'\n", SCRIPTDIR "/repl.pbl");
         fprintf(stderr, "Consider installing or reinstalling pebblisp.\n");
     }
 }
 
+void loadArgsIntoEnv(int argc, const char* argv[], struct Environment* env) {
+    Object args = listObject();
+    for(int i = 0; i < argc; i++) {
+        nf_addToList(&args, stringFromSlice(argv[i], strlen(argv[i])));
+    }
+    addToEnv(env, "args", args);
+}
+
 int main(int argc, const char* argv[])
 {
     struct Environment env = defaultEnv();
     readFile(SCRIPTDIR "/lib.pbl", &env);
+    FILE *file = fopen(argv[1], "r");
     if(argc >= 2) {
-        if(readFile(argv[1], &env) != 0) {
+        if(file) {
+            // Executing a file
+            loadArgsIntoEnv(argc, argv, &env);
+            _readFile(file, &env);
+        } else {
+            // Running arguments directly as pl code
             Object r = numberObject(0);
             for(int i = 1; i < argc; i++) {
                 r = parseEval(argv[i], &env);
@@ -827,6 +844,8 @@ int main(int argc, const char* argv[])
             }
         }
     } else {
+        // Running a repl
+        loadArgsIntoEnv(argc, argv, &env);
         repl(&env);
     }
     deleteEnv(&env);