Fixed cmdline example program

examples/cmdline/api.js

@@ -0,0 +1,4 @@
+({
+   add : function(a, b) { return a + b; },
+   mul : function(a, b) { return a * b; },
+})

examples/cmdline/main.c

@@ -2,40 +2,34 @@
 // All rights reserved
 //
 // Example Elk integration. Demontrates how to implement "require".
-// Create file "api.js" with the following content:
-//  ({
-//    add : function(a, b) { return a + b; },
-//    mul : function(a, b) { return a * b; },
-//  })
-//
 // Compile main.c and run:
-//   $ cc main.c ../../elk.c -I../.. -o cli
+//   $ cc main.c ../../elk.c -I../.. -o cli -DJS_DUMP
 //   $ ./cli 'let math = require("api.js"); math.mul(2,3);'
 //   6
-//   Executed in 0.663 ms. Mem usage is 3% of 8192 bytes.
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "elk.h"
 
-// Prints all arguments, one by one, delimit by space
-static jsval_t js_print(struct js *js, jsval_t *args, int nargs) {
-  for (int i = 0; i < nargs; i++) {
-    const char *space = i == 0 ? "" : " ";
-    printf("%s%s", space, js_str(js, args[i]));
-  }
-  putchar('\n');  // Finish by newline
-  return js_mkundef();
+// Function that loads JS code from a given file.
+static jsval_t js_require(struct js *js, jsval_t *args, int nargs) {
+  if (nargs != 1) return js_mkundef();
+  char data[1024];
+  char *filename = js_getstr(js, args[0], NULL);
+  FILE *fp = fopen(filename, "rb");
+  if (fp == NULL) return js_mkundef();
+  size_t len = fread(data, 1, sizeof(data), fp);
+  return js_eval(js, data, len);
 }
 
 int main(int argc, char *argv[]) {
   char mem[8192], dump = 0;
   struct js *js = js_create(mem, sizeof(mem));
   jsval_t res = js_mkundef();
 
-  // Implement `print` function
-  js_set(js, js_glob(js), "print", js_mkfun(js_print));
+  // Implement `require` function
+  js_set(js, js_glob(js), "require", js_mkfun(js_require));
 
   // Treat every argument as JS expressions. Execute all one by one
   for (int i = 1; i < argc; i++) {