diff --git a/src/nicethings.rkt b/src/nicethings.rkt index d693609..6370e37 100644 --- a/src/nicethings.rkt +++ b/src/nicethings.rkt @@ -8,92 +8,88 @@ ;; ------------------------------------------------ ;; Constants ;; ------------------------------------------------ -(define help-command-1 "help") -(define help-command-2 "--help") -(define help-command-3 "-h") -(define init-command "init") -(define ls-command "ls") -(define rm-command "rm") -(define add-command "add") -(define program-name "nicethings") -(define program-file (string-append "." program-name)) -(define program-path (build-path (find-system-path 'home-dir) program-file)) -(define program-permissions 420) ;; 644/-rw-r--r-- permissions -(define newline "\n") -(define double-newline "\n\n") +(define help-command-1 "help") +(define help-command-2 "--help") +(define help-command-3 "-h") +(define init-command "init") +(define ls-command "ls") +(define rm-command "rm") +(define add-command "add") +(define program-name "nicethings") +(define program-file (string-append "." program-name)) +(define program-path (path->string (build-path (find-system-path 'home-dir) program-file)) +(define read-permissions 444) +(define newline "\n") +(define double-newline "\n\n") ;; ------------------------------------------------ ;; Messages ;; ------------------------------------------------ (define messages - (hash - 'error-too-many-arguments - (format (string-append "Error: Too many arguments." newline - "Try running '~a ~a' for more information.") - program-name - help-command-1) + (hash 'error-too-many-arguments + (format (string-append "Error: Too many arguments." newline + "Try running '~a ~a' for more information.") + program-name + help-command-1) - 'error-incorrect-usage - (format (string-append "Error: Incorrect usage." newline - "Try running '~a ~a' for more information.") - program-name - help-command-1) + 'error-incorrect-usage + (format (string-append "Error: Incorrect usage." newline + "Try running '~a ~a' for more information.") + program-name + help-command-1) - 'error-file-already-exists - (format "Error: The file '~a' already exists." program-path) + 'couldnt-find-file + (format (string-append "Error: Couldn't find ~a" newline + "Either the file doesn't exist, or the permissions are incorrect." newline + "If the file exists, try running chmod 600 ~a") + program-path + program-path) - 'error-fake-file-exists - (format (string-append "Error: The directory '~a' exists." newline - "Try moving, renaming, or deleting this directory.") - program-path) + 'error-something-exists + (format "Error: It looks like ~a already exists." program-path) - 'error-file-doesnt-exist - (format (string-append "Error: '~a' doesn't exist." newline - "Try running '~a ~a'.") - program-path - program-name - init-command) + 'error-file-doesnt-exist + (format (string-append "Error: '~a' doesn't exist." newline + "Try running '~a ~a'.") + program-path + program-name + init-command) - 'error-item-not-found - "Error: Item not found." + 'error-item-not-found + "Error: Item not found." + 'error-not-an-option + "Error: not an option." - 'warning-permissions - (format (string-append "Warning: The permissions on your '~a' file are incorrect." newline - "Other users on this host may be able to read your file." newline - "Try running 'chmod 600 ~a' to fix this." newline) - program-path - program-path) + 'error-not-a-number + "Error: not a number." - 'init-cancelled - (format "Cancelled the creation of '~a'." program-path) + 'warning-permissions + (format (string-append "Warning: The permissions on your '~a' file are incorrect." newline + "Other users on this host may be able to read your file." newline + "Try running 'chmod 600 ~a' to fix this." newline) + program-path + program-path) - 'init-prompt - (format (string-append "~a will create '~a'." newline - "Is this okay? [y/n]") - program-name - program-path) + 'init-cancelled + (format "Cancelled the creation of '~a'." program-path) - 'file-created - (format "Successfully created ~a." program-path) + 'init-prompt + (format (string-append "The file '~a' will be created." newline + "Is this okay? [y/n]") + program-path) - 'empty-list - "There is nothing in your list.")) + 'file-created + (format "Successfully created ~a." program-path) -(define formatees - (hash - 'error-not-an-option - (string-append "Error: '~a' is not an option." newline - "Please choose 'y' or 'n'.") + 'empty-list + "There is nothing in your list." - 'error-not-a-number - (string-append "Error: '~a' is not a number.") + 'added + "Added '~a' to your list." - 'added - "Added '~a' to your list." - - 'removed - "Removed '~a' from your list.")) + 'removed + "Removed '~a' from your list.")) ;; ------------------------------------------------ ;; helpers @@ -101,95 +97,57 @@ (define (messages-ref key) (hash-ref messages key)) -(define (formatees-ref key) - (hash-ref formatees key)) - (define (displayln-messages-ref key) - (let ([message (messages-ref key)]) - (displayln message))) + (displayln (messages-ref key))) -(define (displayln-formatees-ref key string) - (let* ([formatee (formatees-ref key)] - [formatee-formatted (format formatee string)]) - (displayln formatee-formatted))) +(define (displayln-format-messages-ref key value) + (displayln (format (messages-ref key) value))) (define (create-file string) - (close-output-port - (open-output-file string))) + (close-output-port (open-output-file string))) -(define (has-program-permissions? string) +(define (has-read-permissions? string) (equal? program-permissions (file-or-directory-permissions string 'bits))) -;; ------------------------------------------------ -;; Check conditions -;; ------------------------------------------------ -(define (check-conditions) - (cond - [(directory-exists? program-path) - (begin (displayln-messages-ref 'error-fake-file-exists) - (exit))] - - [(not (file-exists? program-path)) - (begin (displayln-messages-ref 'error-file-doesnt-exist) - (exit))] - - [(not (has-program-permissions? program-path)) - (displayln-messages-ref 'warning-permissions)] - - [else 'do-nothing])) - - ;; ------------------------------------------------ ;; init ;; ------------------------------------------------ -(define (init/create-file) - (create-file program-path) - (file-or-directory-permissions program-path - program-permissions) - (displayln-messages-ref 'file-created)) - (define (init/cancel) (displayln-messages-ref 'init-cancelled) (exit)) +(define (init/create-file) + (create-file program-path) + (file-or-directory-permissions program-path read-permissions) + (displayln-messages-ref 'file-created)) + (define (init/prompt) (displayln-messages-ref 'init-prompt) (display "> ") - (let* ([input (read-line)] - [input-symbol (string->symbol input)]) + (let ([input-symbol (string->symbol (read-line))]) (case input-symbol - ['y (init/create-file)] - ['n (init/cancel)] - [else (displayln-formatees-ref 'error-not-an-option input)]))) + ['y (init/create-file)] + ['n (init/cancel)] + [else (displayln-messages-ref 'error-not-an-option)]))) (define (init) - (cond - [(file-exists? program-path) - (displayln-messages-ref 'error-file-already-exists)] - - [(directory-exists? program-path) - (displayln-messages-ref 'error-fake-file-exists)] - - [else (init/prompt)])) + (if (or (file-exists? program-path) + (directory-exists? program-path)) + (displayln-messages-ref 'error-something-exists) + (init/prompt))) ;; ------------------------------------------------ ;; ls ;; ------------------------------------------------ (define (ls/display-list listof-items) - ;; The add1 in the first binding starts the - ;; listof-numbers at 1 instead of 0 to make the - ;; list numbering more human-friendly - (let* ([listof-numbers (map add1 (range (length listof-items)))] - [listof-number-strings (map number->string listof-numbers)] - [combine-lists (lambda (a b) (string-append a ". " b))] - [listof-numbered-items (map combine-lists + (let* ([listof-number-strings (map number->string (range (length listof-items)))] + [listof-numbered-items (map (lambda (a b) (string-append a ". " b)) listof-number-strings listof-items)]) (for ([item listof-numbered-items]) (displayln item)))) (define (ls) - (check-conditions) (let ([listof-items (file->lines program-path)]) (if (null? listof-items) (displayln-messages-ref 'empty-list) @@ -198,78 +156,50 @@ ;; ------------------------------------------------ ;; rm ;; ------------------------------------------------ -(define (rm/remove-item listof-items item-number) - (let* ([item-to-remove (list-ref listof-items item-number)] - [list-without-item (remove item-to-remove listof-items)]) - (display-lines-to-file list-without-item - program-path - #:exists 'truncate) - (displayln-formatees-ref 'removed item-to-remove))) - -(define (rm/process-string string) - (let* ([listof-items (file->lines program-path)] - [item-number (string->number string)] - ;; Subtract 1 from the user's original number, - ;; because we want to convert the number from - ;; human numbers (1 2 3) to index numbers - ;; (0 1 2) - [item-number-sub1 (sub1 item-number)] - [list-length (length listof-items)]) +(define (rm/remove-nicething item-number) + (let ([listof-items (file->lines program-path)]) (if (and (not (null? listof-items)) - (number? item-number) - (positive? item-number) - ;; Don't allow numbers that are equal to - ;; or greater than list-length, because - ;; the list index starts at 0 - ;; - ;; Example: - ;; Length of (1 2 3) = 3 - ;; - ;; To reference the highest number, we - ;; use (list-ref (1 2 3) 2) - (< item-number-sub1 list-length)) - (rm/remove-item listof-items item-number-sub1) - (displayln-messages-ref 'error-item-not-found)))) + (>= item-number 0) + (< item-number (length listof-items))) + (let* ([item-to-remove (list-ref listof-items item-number)] + [list-without-item (remove item-to-remove listof-items)]) + (display-lines-to-file list-without-item program-path #:exists 'truncate) + (displayln-format-messages-ref 'removed item-to-remove)) + (displayln-messages-ref 'error-item-not-found)))) -(define (rm string) - (check-conditions) - (if (string->number string) - (rm/process-string string) - (displayln-formatees-ref 'error-not-a-number string))) +(define (rm arg) + (let ([item-number (string->number arg)]) + (if item-number + (rm/remove-nicething item-number) + (displayln-format-messages-ref 'error-not-a-number arg)))) ;; ------------------------------------------------ ;; add ;; ------------------------------------------------ -(define (add string) - (check-conditions) +(define (add nicething) ;; The removing and adding of the '\n' is to ;; ensure only one '\n' exists at the end of the ;; item to be added. - (let* ([string-no-newline (string-replace string "\n" "")] - [string-newline (string-append string-no-newline "\n")]) - (display-to-file string-newline - program-path - #:exists 'append) - (displayln-formatees-ref 'added string-no-newline))) + (let* ([nicething-no-newline (string-replace nicething "\n" "")] + [nicething-newline (string-append nicething-no-newline "\n")]) + (display-to-file nicething-newline program-path #:exists 'append) + (displayln-format-messages-ref 'added nicething-no-newline))) ;; ------------------------------------------------ ;; random message ;; ------------------------------------------------ -(define (random-message/append-program-file home-directory) - (build-path home-directory program-file)) - (define (random-message) - (let* ([root (find-system-path 'sys-dir)] ;; / - [root-home (build-path root "home")] ;; /home + (let* ([root-home (build-path (find-system-path 'sys-dir) "home")] ;; /home ;; `#:build? #t` Builds full paths for all items listed in /home/ - [listof-home-directories (directory-list root-home #:build? #t)] - [listof-nicethings-paths (map random-message/append-program-file listof-home-directories)] - [directories-with-nicethings (filter file-exists? listof-nicethings-paths)] - [directories-with-644 (filter has-program-permissions? directories-with-nicethings)] - [listof-nicethings (apply append (map file->lines directories-with-644))] - [list-length (length listof-nicethings)]) + [listof-home-directories (directory-list root-home #:build? #t)] + [listof-nicethings-paths (map (lambda (x) (build-path x program-file)) + (listof-home-directories))] + [paths-with-nicethings (filter file-exists? listof-nicethings-paths)] + [paths-readable (filter has-read-permissions? paths-with-nicethings)] + [listof-nicethings (apply append (map file->lines paths-readable))] + [list-length (length listof-nicethings)]) (when (not (zero? list-length)) - (let* ([random-number (random list-length)] + (let* ([random-number (random list-length)] [random-nicething (list-ref listof-nicethings random-number)]) (displayln random-nicething))))) @@ -279,26 +209,26 @@ (define (help) (displayln (string-append - "Usage:" newline - (format " ~a [] []" program-name) - double-newline + "Usage:" newline + (format " ~a [] []" program-name) + double-newline - "Commands:" newline - " No command - Displays a random nicething from a random user." newline - (format " ~a - Creates a file in ~a, which allows you to contribute to the town-wide list of nicethings." - init-command - program-path) newline - (format " ~a - Adds a nicething to your list." add-command) newline - (format " ~a - Prints a numbered list of the nicethings you've added." ls-command) newline - (format " ~a - Removes a nicething from your list." rm-command) - double-newline + "Commands:" newline + " No command - Displays a random nicething from a random user." newline + (format " ~a - Creates a file in ~a, which allows you to contribute to the town-wide list of nicethings." + init-command + program-path) newline + (format " ~a - Adds a nicething to your list." add-command) newline + (format " ~a - Prints a numbered list of the nicethings you've added." ls-command) newline + (format " ~a - Removes a nicething from your list." rm-command) + double-newline - "Examples:" newline - (format " ~a" program-name) newline - (format " ~a ~a" program-name init-command) newline - (format " ~a ~a \"You are wonderful\"" program-name add-command) newline - (format " ~a ~a" program-name ls-command) newline - (format " ~a ~a 2" program-name rm-command)))) + "Examples:" newline + (format " ~a" program-name) newline + (format " ~a ~a" program-name init-command) newline + (format " ~a ~a \"You are wonderful\"" program-name add-command) newline + (format " ~a ~a" program-name ls-command) newline + (format " ~a ~a 2" program-name rm-command)))) (define (process-args vectorof-args) (match vectorof-args @@ -308,11 +238,14 @@ [(vector (== ls-command)) (ls)] [(vector (== init-command)) (init)] [(vector (== add-command) a) (add a)] - [(vector (== rm-command) a) (rm a)] + [(vector (== rm-command) a) (rm a)] [_ (random-message)] [(vector _ ...) (displayln-messages-ref 'error-incorrect-usage)])) (define (main vectorof-args) - (process-args vectorof-args)) + (if (and (file-exists program-file) + (has-read-permissions? program-file)) + (process-args vectorof-args) + (displayln-messages-ref 'couldnt-find-file))) (main (current-command-line-arguments))