1 files changed, 103 insertions, 0 deletions
diff --git a/src/user/app/kbasic/commands.c b/src/user/app/kbasic/commands.c
new file mode 100644
index 0000000..f60f32a
--- /dev/null
+++ b/src/user/app/kbasic/commands.c
@@ -0,0 +1,103 @@
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "basic.h"
+
+/* Assign a variable a value. */
+void assignment()
+{
+	int *var;
+	int value;
+
+	/* get the variable name */
+	get_token();
+	if(!isalpha(*token)) {
+		serror(4);
+		return;
+	}
+
+	var = find_var(token);
+
+	/* get the equals sign */
+	get_token();
+	if(*token!='=') {
+		serror(3);
+		return;
+	}
+
+	/* get the value to assign to var */
+	get_exp(&value);
+
+	/* assign the value */
+	*var = value;
+}
+
+
+
+/* Execute a simple version of the BASIC PRINT statement */
+void exec_print()
+{
+	int answer;
+	int len=0, spaces;
+	char last_delim;
+
+	do {
+		get_token(); /* get next list item */
+		if(tok==EOL || tok==FINISHED) break;
+		if(token_type==QUOTE) { /* is string */
+			printf("%s", token);
+			len += strlen(token);
+			get_token();
+		}
+		else { /* is expression */
+			putback();
+			get_exp(&answer);
+			get_token();
+			len += printf("%d", answer);
+		}
+		last_delim = *token; 
+
+		if(*token==';') {
+			/* compute number of spaces to move to next tab */
+			spaces = 8 - (len % 8); 
+			len += spaces; /* add in the tabbing position */
+			while(spaces) { 
+				printf(" ");
+				spaces--;
+			}
+		}
+		else if(*token==',') /* do nothing */;
+		else if(tok!=EOL && tok!=FINISHED) serror(0); 
+	} while (*token==';' || *token==',');
+
+	if(tok==EOL || tok==FINISHED) {
+		if(last_delim != ';' && last_delim!=',') printf("\n");
+	}
+	else serror(0); /* error is not , or ; */
+
+}
+
+/* Execute a simple form of the BASIC INPUT command */
+void input()
+{
+	int *var;
+	int tmp;
+
+	get_token(); /* see if prompt string is present */
+	if(token_type==QUOTE) {
+		printf("%s", token); /* if so, print it and check for comma */
+		get_token();
+		if(*token!=',') serror(1);
+		get_token();
+	}
+	else printf("? "); /* otherwise, prompt with / */
+
+	var = find_var(token); /* get the input var */
+
+	scanf("%d\n", var); /* read input */
+
+	/* flush input */
+	while ((tmp = getchar()) != '\n' && tmp != EOF);
+}
+