emul/forth: allow running commands from file

emul/forth/forth.c

@@ -10,10 +10,11 @@
 #define STDIO_PORT 0x00
 
 static int running;
+static FILE *fp;
 
 static uint8_t iord_stdio()
 {
-    int c = getchar();
+    int c = getc(fp);
     if (c == EOF) {
         running = 0;
     }
@@ -31,19 +32,31 @@ static void iowr_stdio(uint8_t val)
 
 int main(int argc, char *argv[])
 {
-    bool tty = isatty(fileno(stdin));
+    bool tty = false;
     struct termios termInfo;
-    if (tty) {
-        // Turn echo off: the shell takes care of its own echoing.
-        if (tcgetattr(0, &termInfo) == -1) {
-            printf("Can't setup terminal.\n");
+    if (argc == 2) {
+        fp = fopen(argv[1], "r");
+        if (fp == NULL) {
+            fprintf(stderr, "Can't open %s\n", argv[1]);
             return 1;
         }
-        termInfo.c_lflag &= ~ECHO;
-        termInfo.c_lflag &= ~ICANON;
-        tcsetattr(0, TCSAFLUSH, &termInfo);
+    } else if (argc == 1) {
+        fp = stdin;
+        tty = isatty(fileno(stdin));
+        if (tty) {
+            // Turn echo off: the shell takes care of its own echoing.
+            if (tcgetattr(0, &termInfo) == -1) {
+                printf("Can't setup terminal.\n");
+                return 1;
+            }
+            termInfo.c_lflag &= ~ECHO;
+            termInfo.c_lflag &= ~ICANON;
+            tcsetattr(0, TCSAFLUSH, &termInfo);
+        }
+    } else {
+        fprintf(stderr, "Usage: ./forth [filename]\n");
+        return 1;
     }
-
     Machine *m = emul_init();
     m->ramstart = RAMSTART;
     m->iord[STDIO_PORT] = iord_stdio;
@@ -58,11 +71,12 @@ int main(int argc, char *argv[])
     while (running && emul_step());
 
     if (tty) {
-        printf("Done!\n");
+        printf("\nDone!\n");
         termInfo.c_lflag |= ECHO;
         termInfo.c_lflag |= ICANON;
         tcsetattr(0, TCSAFLUSH, &termInfo);
         emul_printdebug();
     }
+    fclose(fp);
     return 0;
 }