Long description

Line 1, at indentation level 0: const h t t p equals require open parenthesis open double quotes h t t p close double quotes semicolon.

Line 2, at indentation level 0: const u r l equals require open parenthesis open double quotes u r l close double quotes close parenthesis semicolon.

Line 3, at indentation level 0: const path equals require open parenthesis open double quotes path close double quotes close parenthesis semicolon.

Line 4, at indentation level 0: const f s equals require open parenthesis open double quotes f s close double quotes close parenthesis semicolon.

Line 5, at indentation level 0: forward slash forward slash our H T T P server now returns requested files.

Line 6, at indentation level 0: const server equals h t t p. createServer open parenthesis function open parenthesis request, response close parenthesis open curly brace.

Line 7, at indentation level 1: forward slash forward slash get the filename from the U R L.

Line 8, at indentation level 1: StartCommand let EndCommand requestedFile equals u r l dot parse open parenthesis request dot u r l close parenthesis dot pathname semicolon.

Line 9, at indentation level 1: forward slash forward slash now turn that into a file system file name by adding the current.

Line 10, at indentation level 1: forward slash forward slash local folder path in front of the filename.

Line 11, at indentation level 1: StartCommand let EndCommand filename equals path dot join open parenthesis process dot c w d open parenthesis close parenthesis comma requestedFile close parenthesis semicolon.

Line 12, at indentation level 1: forward slash forward slash check if it exists on the computer.

Line 13, at indentation level 1: f s dot exists open parenthesis filename comma function open parenthesis exists close parenthesis open curly brace.

Line 14at indentation level 2 : forward slash forward slash if it does not exist, then return a 404 response,.

Line 15, at indentation level 2: StartCommand if EndCommand open parenthesis exclamation mark exists close parenthesis open curly brace.

Line 16, at indentation level 3: response dot writeHead open parenthesis 404 comma open curly brace open double quotes Content hyphen Type close double quotes colon open double quotes text forward slash html close double quotes close curly brace close parenthesis close parenthesis semicolon.

Line 17, at indentation level 3: response dot write open parenthesis open double quotes open angle bracket h 1 close angle bracket 404 Error open angle bracket forward slash h 1 close angle bracket backslash n close double quotes close parenthesis close parenthesis semicolon.

Line 18, at indentation level 3: response dot write open parenthesis open double quotes The requested file isn't on this machine backslash n close double quotes close parenthesis semicolon.

Line 19, at indentation level 3: response dot end open parenthesis close parenthesis semicolon.

Line 20, at indentation level 3: return semicolon.

Line 21, at indentation level 2: close curly brace.

Line 22, at indentation level 2: forward slash forward slash if file exists then read it in and send its.

Line 23, at indentation level 2: forward slash forward slash contents to requestor.

Line 24, at indentation level 2: f s dot readFile open parenthesis filename comma open double quotes binary close double quotes comma function open parenthesis err comma file close parenthesis open curly brace.

Line 25, at indentation level 3: forward slash forward slash maybe something went wrong (example permission error).

Line 26, at indentation level 3: StartCommand if EndCommand open parenthesis err close parenthesis open curly brace.

Line 27, at indentation level 4: response dot writeHead open parenthesis 500 comma open curly brace open double quotes Content hyphen Type close double quotes colon open double quotes text forward slash h t m l close double quotes close curly brace close parenthesis semicolon.

Line 28, at indentation level 4: response dot write open parenthesis open double quotes open angle bracket h 1 close angle bracket 500 Error open angle bracket forward slash h1 close angle bracket backslash n close double quotes close parenthesis semicolon.

Line 29, at indentation level 4: response dot write open parenthesis err plus open double quotes In close double quotes close parenthesis semicolon.

Line 30, at indentation level 4: response dot end open parenthesis close parenthesis semicolon.

Line 31, at indentation level 4: return semicolon.

Line 32, at indentation level 3: close curly brace.

Line 33, at indentation level 3: forward slash forward slash everything is fine so return contents of file.

Line 34, at indentation level 3: response dot writeHead open parenthesis 200 close parenthesis semicolon.

Line 35, at indentation level 3: response dot write open parenthesis file comma open double quotes binary close double quotes close parenthesis semicolon.

Line 36, at indentation level 3: response dot end open parenthesis close parenthesis semicolon.

Line 37, at indentation level 2: close curly brace close parenthesis semicolon.

Line 38, at indentation level 1: close curly brace close parenthesis semicolon.

Line 39, at indentation level 0: close curly brace close parenthesis semicolon.

Line 40: forward slash forward slash we do not have to use port 8080 semicolon here we are using 7000.

Line 41, at indentation level 0: server dot listen open parenthesis 7000 comma open double quotes localhost close double quotes close parenthesis semicolon.

Line 42, at indentation level 0: console dot log open parenthesis open double quotes Server running at h t p colon forward slash forward slash 127 dot 0 dot 0 dot 1 colon 7000 forward slash close double quotes close parenthesis semicolon.

Note: Line 2 to Line 4 is labeled Using three new modules in this example that process URL paths and read forward slash write local files.

First browser window: Line 20 points to a browser window that shows a level-1 heading and a level-2 heading. Level-1 heading reads: 404 Error. Level-2 heading reads: The requested file isn't on this machine.

Second browser window: Line 35 points to a browser window at the right. The browser window is labeled Venice dot j p g (640 cross 480) and shows an image of a canal with buildings at both sides of the canal.