fix fd_check

student-distrib/proc.c

@@ -27,10 +27,14 @@ void control_initilization(void)
 //checking is fd is valid
 int32_t fd_check(int32_t fd)
 {
-    if( control.terminal[control.cur_terminal].pcb->fd[fd].flags != 0 &&
-        fd >= MIN_FILE_NUM &&
-        fd <  MAX_FILE_NUM ){ return 1; }
-    else { return 0; }
+    if( fd >= MIN_FILE_NUM &&
+        fd <  MAX_FILE_NUM ){ return -1; }
+
+    // file not present
+    if (control.terminal[control.cur_terminal].pcb->fd[fd].flags == 0)
+        return -1;
+
+    else return 0;
 }
 
 //clearing fd
@@ -74,7 +78,6 @@ void pcb_init(pcb_t* pcb , uint8_t* parsed_cmd, uint8_t (*argv)[MAX_ARGUMENT_SIZ
 
     //initialize other things in pcb structures
     pcb->pid      = pid;
-    //pcb->parent_pid = (control.terminal[control.cur_terminal].terminal_prog_count - 1 == 0) ? pid - 1: control.terminal[control.cur_terminal].pcb->pid;
     // no program other than the shell initiates another program
     pcb->parent_pid = 0;
 
@@ -224,8 +227,8 @@ int32_t set_pid(void)
     for (i = 0; i < MAX_PROCESS; i++)
     {
         if (control.pid_array[i] == 0){
-        	control.pid_array[i] = 1;
-	    	return i;
+            control.pid_array[i] = 1;
+            return i;
         }
     }
     printf("Reached maximum number of processes %d\n", MAX_PROCESS);

student-distrib/terminal.c

@@ -170,7 +170,7 @@ void init_terminal(void)
 /*
  *  FUNCTIONALITY: switching terminal
  *
- *  INPUT: the terminal id of the ther terminal that we want to switch to
+ *  INPUT: the terminal id of the terminal that we want to switch to
  *
  *  OUTPUT: -2 - invalid terminal ID or maximum number of processes reached
  *          -1 - trying to switch to same terminal
@@ -196,15 +196,14 @@ int32_t switch_terminal(int32_t term_id)
     control.cur_terminal = term_id;
     control.visible_terminal = term_id;
 
-    //store previous terminal data
-    //copy_term_data(prev_terminal, 0);
+    //store previous terminal data into memory
     memcpy( (void*)control.terminal[prev_terminal].vid_mem, (const void*)TERM_VID, _4_KB );
 
     //remap_term(term_id);
     clear();
     update_cursor();
     
-    //copy_term_data(control.cur_terminal, 1);
+    //display new terminal video memory
     memcpy( (void*)TERM_VID, (const void*)control.terminal[term_id].vid_mem, _4_KB );
 
     //check if shell is running on that terminal

student-distrib/types.h

@@ -161,9 +161,9 @@ typedef struct pcb {
 
 /* Terminal structure - Up to 3 terminals supported */
 typedef struct terminal {
-         pcb_t   *  pcb;
-         int32_t    terminal_x;
-         int32_t    terminal_y;
+         pcb_t*     pcb;
+         int32_t    terminal_x; // cursor location
+         int32_t    terminal_y; // cursor location
 
          int32_t    vid_mem;
          int32_t    terminal_prog_count;
@@ -193,7 +193,6 @@ typedef struct control {
 
 /*---------------------------- Global variable -------------------------------*/
 
-/* Godlike--- */
 control_t control;
 
 f_table_t dir_jumptable    ;