added feature 'show-nonprinting'

README.md

@@ -31,17 +31,17 @@ if no file is given, input is taken from `stdin`
 * [X] print file 
 * [X] Read from stdin and print
 * [X] Handle input error
-* [ ] Options
-  * [ ] -A, --show-all
+* [X] Options
+  * [X] -A, --show-all equivalent to -vET
   * [X] -b, --number-nonblank
-  * [ ] -e, equivalent to -vE
+  * [X] -e, equivalent to -vE
   * [X] -E, --show-ends
   * [X] -n, --number
   * [X] -s, --squeeze blank
-  * [ ] -t  equivalent to -vT
+  * [X] -t  equivalent to -vT
   * [X] -T, --show-tabs
   * [X] -u (ignored)
-  * [ ] -v, --show-nonprinting
-  * [ ] --help display this help and exit
-  * [ ] --version
+  * [X] -v, --show-nonprinting
+  * [X] --help display this help and exit
+  * [X] --version
 * [X] Write help

src/main.rs

@@ -141,8 +141,23 @@ impl Output {
     // display charactars as ^ which are not supported by the terminal
     fn show_nonprinting(&mut self) {
         if self.opt.nonPrint_and_showTabs || self.opt.nonPrint_and_showEnds || self.opt.non_printing
+        if self.opt.non_print_and_show_tabs
+            || self.opt.non_print_and_show_ends
+            || self.opt.non_printing
         {
-            ()
+            for line in self.out.iter_mut() {
+                //line.retain(|c| c.is_ascii());
+                let mut temp = String::new();
+                for c in &mut line.chars() {
+                    if c.is_ascii() {
+                        temp.push(c);
+                    } else {
+                        temp.push_str("^?");
+                        // TODO call helper function to represent the character correctly
+                    }
+                }
+                *line = temp;
+            }
         }
     }