allow source filename to be specified on the command line

Author: tcort

main.c

@@ -28,11 +28,23 @@ SOFTWARE.
 static vm_t vm;
 
 int main(int argc, char *argv[]) {
-	(void)argc; (void)argv;
 
-	load(&vm);
+	FILE *in = stdin;
+	if (argc == 2) {
+		in = fopen(argv[1], "r");
+		if (in == NULL) {
+			perror(argv[0]);
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	load(&vm, in);
 	run(&vm);
 
+	if (argc == 2) {
+		fclose(in);
+	}
+
 	exit(EXIT_SUCCESS);
 }
 

vm.c

@@ -63,14 +63,14 @@ static op_t opcodes[NOPS] = {
 };
 
 
-void load(vm_t *vm) {
+void load(vm_t *vm, FILE *in) {
 
 	char line[96]; /* TODO move to const.h */
 	int cap = 96;
 
 	memset(vm, '\0', sizeof(vm_t));
 
-	while (fgets(line, cap, stdin) != NULL) {
+	while (fgets(line, cap, in) != NULL) {
 
 		chomp(line);
 

vm.h

@@ -23,10 +23,12 @@ SOFTWARE.
 #ifndef __VM_H
 #define __VM_H
 
+#include <stdio.h>
+
 #include "const.h"
 #include "types.h"
 
-void load(vm_t *vm);
+void load(vm_t *vm, FILE *in);
 void run(vm_t *vm);
 
 #endif