Added a shell when no arguments are given to sloth.

Now has a new dependencies on editline library.

.gitignore

@@ -8,6 +8,7 @@ src/variables/variable.o
 src/variables/value.o
 src/operations/node.o
 src/operations/operators.o
+src/shell.o
 sloth
 vgcore*
 .vscode

Makefile

@@ -1,5 +1,5 @@
-sloth: src/main.c src/parser/lex.yy.o src/parser/parser.tab.o src/variables/environment.o src/variables/variable.o src/variables/value.o src/operations/node.o src/operations/operators.o
+sloth: src/main.c src/parser/lex.yy.o src/parser/parser.tab.o src/variables/environment.o src/variables/variable.o src/variables/value.o src/operations/node.o src/operations/operators.o src/shell.o
-	gcc src/main.c src/parser/lex.yy.o src/parser/parser.tab.o src/variables/environment.o src/variables/variable.o src/variables/value.o src/operations/node.o src/operations/operators.o -o sloth
+	gcc src/main.c src/parser/lex.yy.o src/parser/parser.tab.o src/variables/environment.o src/variables/variable.o src/variables/value.o src/operations/node.o src/operations/operators.o src/shell.o -ledit -o sloth
 src/parser/lex.yy.o: src/parser/lex.yy.c src/parser/parser.tab.h
 	gcc -c src/parser/lex.yy.c -o src/parser/lex.yy.o
 src/parser/parser.tab.o: src/parser/parser.tab.c
@@ -20,5 +20,7 @@ src/operations/operators.o: src/operations/operators.h  src/operations/operators
 	gcc -c src/operations/operators.c -o src/operations/operators.o
 src/operations/node.o: src/operations/node.h src/operations/node.c
 	gcc -c src/operations/node.c -o src/operations/node.o
+src/shell.o: src/shell.h src/shell.c
+	gcc -c src/shell.c -o src/shell.o
 clean:
-	rm src/parser/lex.yy.c src/parser/parser.tab.c src/parser/parser.tab.h src/parser/lex.yy.o src/parser/parser.tab.o src/variables/environment.o src/variables/variable.o src/variables/value.o src/operations/node.o src/operations/operators.o sloth
+	rm src/parser/lex.yy.c src/parser/parser.tab.c src/parser/parser.tab.h src/parser/lex.yy.o src/parser/parser.tab.o src/variables/environment.o src/variables/variable.o src/variables/value.o src/operations/node.o src/operations/operators.o src/shell.o sloth

src/main.c

@@ -1,19 +1,31 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include "sloth.h"
+#include "shell.h"
+
+void interpret_file(char* fileName);
 
 /* the result variable */
 struct Node* result;
 
 int main(int argc, char* argv[]) {
-  if (argc != 2) {
+  if (argc == 1) {
-    printf("Incorrect number of arguments passed. Expected %d, got %d.\n", 1, argc - 1);
+    start_shell();
+  } else if (argc == 2) {
+    interpret_file(argv[1]);
+  } else {
+    printf("Incorrect number of arguments passed. Expected %d or %d, got %d.\n", 0, 1, argc - 1);
     printf("Usage: lexer [program_name].sl\n");
     exit(-1);
   }
+
+}
+
+
+void interpret_file(char* fileName) {
   /* save stdin */
   FILE* orig_stdin = stdin;
-  stdin = fopen(argv[1], "r");
+  stdin = fopen(fileName, "r");
   
   yyparse( );
 
@@ -27,5 +39,4 @@ int main(int argc, char* argv[]) {
   eval_statement(result, env);
   delete_environment(env);
   delete_tree(result);
-  return 0;
 }

src/shell.c

@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <string.h>
+#include "shell.h"
+#include "variables/environment.h"
+#include "operations/node.h"
+
+
+// For keeping track of command history
+#ifdef _WIN32 // If we're compiling on windows
+#include <string.h>
+static char buffer[2048];
+// Fake readline function
+char* readline(char* prompt) {
+        fputs(prompt, stdout);
+        fgets(buffer, 2048, stdin);
+        char* cpy = malloc(strlen(buffer) + 1);
+        strcpy(cpy, buffer);
+        cpy[strlen(cpy) - 1] = '\0';
+        return cpy;
+}
+void add_history(char* unused) {}
+
+#else // Otherwise we'll just use the handy readline library
+#include <editline/readline.h>
+#endif
+
+
+struct Node* result;
+
+FILE* stringToFile(char* str) { // Creates a temporary file with the given string as its contents
+    int i = 0; 
+  
+    FILE* tmp = tmpfile(); 
+    if (tmp == NULL) { 
+        fprintf(stderr, "Unable to create temp file"); 
+        return NULL; 
+    } 
+  
+    while (str[i] != '\0') { 
+        fputc(str[i], tmp); i++; 
+    } 
+  
+    // Set the file pointer to the beginning 
+    rewind(tmp); 
+    return tmp;
+}
+
+void start_shell() {
+    printf("Welcome to SLOTH Version 0.0.1\n");
+    printf("Press CTRL+C to Exit\n");
+
+    struct Environment* env = create_environment();
+    while (1) {
+        // Read line from user and input it into the history
+        char* input = readline("sloth> ");
+        add_history(input);
+        // If user enters "exit" quit the loop
+        if (strcmp(input, "exit") == 0) { break; }
+        FILE* inputAsFile = stringToFile(input);
+        /* save stdin */
+        FILE* orig_stdin = stdin;
+        stdin = inputAsFile;
+  
+        yyparse( );
+
+        /* restore stdin */
+        fclose(stdin);
+        stdin = orig_stdin;
+
+        eval_statement(result, env);
+    }
+
+    delete_environment(env);
+    delete_tree(result);
+}

src/shell.h

@@ -0,0 +1,7 @@
+#ifndef SHELL_H
+#define SHELL_H
+
+FILE* stringToFile(char* str);
+void start_shell();
+
+#endif