File system --documentation

Author: irfanbacker

File_System/js/single.js

@@ -1,12 +1,13 @@
-var clipboard = []                // To store files to clipboard to copy or move them 
+var clipboard = []                // To store files to clipboard to copy or move them
 var pre = "user@root"            // Beginning of each terminal line
-var current_path = "/"            // Current location of user     
+var current_path = "/"            // Current location of user
 var pointer = -1                   // pointer points to the index of the current directory
                                    //pointer = -1 corresponds to root directory
 var file_dir = []                 // List of files and directories
-var commands = ["create","vi","rm","truncate","ls","rename","properties","command_list"]
+var commands = ["create","vi","rm","truncate","ls","rename","properties","command_list"] //List of predefined commands
 
 /*
+------------COMMANDS AVAILABLE-------------
 create : For creating a file
 mkdir : Creating a directory
 rmdir : Deleting a directory
@@ -26,8 +27,9 @@ var lslabel
 var index
 
 
-start()
+start()   //Intializing the terminal UI
 
+//Function to run terminal UI
 function start()
 {
  var div = document.getElementById('divx')
@@ -36,42 +38,42 @@ function start()
  textbox = document.createElement('input')
  textbox.setAttribute("class","textbox")
  textbox.setAttribute("type","text")
- textbox.setAttribute("onkeydown","nextline(event,textbox.value)")
+ textbox.setAttribute("onkeydown","nextline(event,textbox.value)") //Detect every key pressed from terminal and send to nextline() function
  div.appendChild(label)
  div.appendChild(textbox)
  div.appendChild(br)
  textbox.focus()
 }
 
-
+//Function to run the input command from terminal
 function nextline(event,text)
 {
  var x = event.keyCode;
- if(x == 13)
+ if(x == 13)                      // On ENTER key press (Keycode of ENTER is 13)
  {
-  divide = text.split(" ")
+  divide = text.split(" ")        //Tokenize command
   user_com = divide[0]
   for(i=0;i<commands.length;i++)
   {
-   if(user_com == commands[i])
+   if(user_com == commands[i])    //Detecting the command (Which command it is)
    {
     break
    }
   }
-  if(i < commands.length)
+  if(i < commands.length)         //Checking if command is predefined ie., is among the predefined list
   {
-   switch(i)
+   switch(i)                      //Running the command
    {
     case 0:create(divide[1])
-	   break    
+	   break
     case 1:vi(divide[1])
-    	   break	
+    	   break
     case 2:rm(divide[1])
     	   break
     case 3:truncate(divide[1])
-    	   break 
+    	   break
     case 4:ls()
-    	   break 
+    	   break
     case 5:rename(divide[1],divide[2])
     	    break
     case 6:properties(divide[1])
@@ -92,48 +94,50 @@ Each entry is a list
 4. Size : Length of content of file - String format
 5. Protection : User, Group, Other
 6. Location : Location of file
-7. Content : String 
+7. Content : String
 */
 
-function create(file)          // Working
+//Function to create a text file. Syntax: create <filename>
+function create(file)
 {
- for(i=0;i<file_dir.length;i++)
+ for(i=0;i<file_dir.length;i++)                                     //Traversing through all files to check if filename already exists
  {
-  if(file_dir[i][0] == file && file_dir[i][2] == pointer)           // Second condition verifies whether elements of current directory are checked 
-  {								    // or not	
+  if(file_dir[i][0] == file && file_dir[i][2] == pointer)           // Second condition verifies whether elements of current directory are checked
+  {								    // or not
    alert("File already exists")
    start()
    return
   }
  }
- file_dir.push([file,0,pointer,0,666,current_path,""])
+ file_dir.push([file,0,pointer,0,666,current_path,""])       //Creating empty file
  start()
 }
 
-
-function ls()                // Working
+//Function to list all content in the directory ie., system
+function ls()
 {
  var div = document.getElementById('divx')
- for(i=0;i<file_dir.length;i++)
+ for(i=0;i<file_dir.length;i++)          //Getting names of all files present
  {
   if(file_dir[i][2] == pointer)
   {
-   var label = document.createTextNode(String(file_dir[i][0]) + " ")
-   div.appendChild(label)   
+   var label = document.createTextNode(String(file_dir[i][0]) + " ")   //Getting filename
+   div.appendChild(label)
   }
- } 
+ }
  var br = document.createElement("br")
- div.appendChild(br) 
+ div.appendChild(br)
  start()
 }
 
-function rm(file)            // Working    
+//Function to remove a file. Syntax: rm <filename>
+function rm(file)
 {
  for(i=0;i<file_dir.length;i++)
  {
-  if(file_dir[i][0] == file && file_dir[i][2] == pointer && file_dir[i][1] == 0)           
-  {								    			 
-   file_dir.splice(i,1)
+  if(file_dir[i][0] == file && file_dir[i][2] == pointer && file_dir[i][1] == 0)  //3rd Check is to confirm this is a file, not a folder
+  {
+   file_dir.splice(i,1)     //Removing file
    start()
    return
   }
@@ -146,28 +150,29 @@ function rm(file)            // Working
  start()
 }
 
-function vi(file)                                       // Working
+//Function to edit a text file. Syntax: vi <filename>
+function vi(file)
 {
  div = document.getElementById('divx')
  var flag = 0
  for(i=0;i<file_dir.length;i++)
  {
-  if(file_dir[i][0] == file && file_dir[i][2] == pointer && file_dir[i][1] == 0)           
-  {		
+  if(file_dir[i][0] == file && file_dir[i][2] == pointer && file_dir[i][1] == 0)
+  {
    flag = 1                                              // File is found
    var br = document.createElement("br")
    var br1 = document.createElement("br")
-   var prompt = document.createTextNode("Press Ctrl to Save and Exit")					    			 	
-   contents = document.createElement('TextArea')
+   var prompt = document.createTextNode("Press Ctrl to Save and Exit")
+   contents = document.createElement('TextArea')         // Create/display textbox to edit/add content to the file
    contents.setAttribute("rows","15")
    contents.setAttribute("cols","120")
    index = i
-   contents.setAttribute("onkeydown","savefile(event,contents.value,index,contents)")
+   contents.setAttribute("onkeydown","savefile(event,contents.value,index,contents)") //Add attribute to DOM to send data on each key press
    contents.value = file_dir[i][6]                      // Contents of file are copied to the textbox
    div.appendChild(prompt)
    div.appendChild(br)
    div.appendChild(contents)
-   div.appendChild(br1)   
+   div.appendChild(br1)
    contents.focus()
   }
  }
@@ -181,27 +186,31 @@ function vi(file)                                       // Working
  }
 }
 
-function savefile(event,text,index,contents)                   // Save contents of file    // Working
+
+//Function to save contents of a file
+function savefile(event,text,index,contents)
 {
  var x = event.keyCode
- if(x == 17)
+ if(x == 17)    //Check if CTRL key is pressed
  {
   file_dir[index][6] = text
   file_dir[index][3] = String(text.length)
   alert("File saved")
-  contents.setAttribute("disabled",true)
+  contents.setAttribute("disabled",true)    //Disable textbox
   start()
  }
-} 
+}
+
 
+//Function to truncate a file. Syntax: truncate <filename>
 function truncate(file)
 {
  for(i=0;i<file_dir.length;i++)
  {
-  if(file_dir[i][0] == file && file_dir[i][2] == pointer && file_dir[i][1] == 0)           
-  {								    			 
-   file_dir[i][6] = ""
-   file_dir[i][3] = "0"
+  if(file_dir[i][0] == file && file_dir[i][2] == pointer && file_dir[i][1] == 0)
+  {
+   file_dir[i][6] = ""  //Set content empty
+   file_dir[i][3] = "0" //Set file size to 0
    start()
    return
   }
@@ -214,13 +223,15 @@ function truncate(file)
  start()
 }
 
+
+//Function to rename file. Syntax: rename <old filename> <new filename>
 function rename(file,name)
 {
  for(i=0;i<file_dir.length;i++)
  {
-  if(file_dir[i][0] == file && file_dir[i][2] == pointer && file_dir[i][1] == 0)           
-  {								    			 
-   file_dir[i][0] = name
+  if(file_dir[i][0] == file && file_dir[i][2] == pointer && file_dir[i][1] == 0)
+  {
+   file_dir[i][0] = name  //Set filename
    start()
    return
   }
@@ -233,15 +244,16 @@ function rename(file,name)
  start()
 }
 
-function properties(file)                      // Working
+//Function to display file properties. Syntax: properties <filename>
+function properties(file)
 {
  for(i=0;i<file_dir.length;i++)
  {
-  if(file_dir[i][0] == file && file_dir[i][2] == pointer && file_dir[i][1] == 0)       // For files    
-  {	
+  if(file_dir[i][0] == file && file_dir[i][2] == pointer && file_dir[i][1] == 0)       // For files
+  {
    var div = document.getElementById('divx')
    var l1 = document.createTextNode("Name : " + file_dir[i][0])
-   var br1 = document.createElement("br")   
+   var br1 = document.createElement("br")
    var l2 = document.createTextNode("Type : text")
    var br2 = document.createElement("br")
    var l3 = document.createTextNode("Size : " + file_dir[i][3])
@@ -268,6 +280,7 @@ function properties(file)                      // Working
  start()
 }
 
+//Function to display available commands list
 function command_list()
 {
  var div = document.getElementById("divx")