feat(command): commands are executed

src/command.c

@@ -0,0 +1,17 @@
+#include "command.h"
+
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "parse.h"
+
+unsigned char invoke(struct Args args) {
+  pid_t child = fork();
+  if (child == 0 && args.argc > 0) {
+    execvp(args.argv[0], args.argv);
+    return 1;
+  }
+  waitpid(child, NULL, 0);
+
+  return 0;
+}

src/command.h

@@ -0,0 +1,8 @@
+#ifndef COMMAND_H
+#define COMMAND_H
+
+#include "parse.h"
+
+unsigned char invoke(struct Args args);
+
+#endif /* COMMAND_H */

src/main.c

@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#include "command.h"
 #include "parse.h"
 #include "reader.h"
 
@@ -14,19 +15,9 @@ int main() {
       return 0;
     }
 
-    printf("command: '%s'\n", input_line);
-
     struct Args args = parse(input_line);
-    unsigned int i = 0;
-    while (i < args.argc) {
-      if (i != 0) {
-        printf(" ");
-      }
-      printf("%s", args.argv[i]);
-      i++;
-    }
-    printf("\n");
-
     free(input_line);
+
+    invoke(args);
   }
 }

src/parse.c

@@ -27,7 +27,9 @@ void add_arg(struct Args *args, char *arg_ptr, unsigned int arg_length) {
 void parse_worker(struct Args *args, char *arg_position,
                   unsigned int arg_length, char *line) {
   if (line[0] == '\n') {
-    add_arg(args, arg_position, arg_length);
+    if (arg_length != 0) {
+      add_arg(args, arg_position, arg_length);
+    }
     return;
   } else if (isspace(line[0])) {
     add_arg(args, arg_position, arg_length);