minor updates for improved performance, probably

src/main.rs

@@ -83,14 +83,20 @@ fn main() -> Result<(), Error> {
                     if d.0 == w {
                         wch = true;
                     }
-                } else { wch = true; }
+                } else {
+                    wch = true;
+                }
                 if let Some(h) = args.height.clone() {
                     if d.1 == h {
                         hch = true;
                     }
-                } else { hch = true; }
+                } else {
+                    hch = true;
+                }
+            }
+            if wch && hch {
+                chk = false;
             }
-            if wch && hch { chk = false; }
         }
         p
     } else {
@@ -101,32 +107,28 @@ fn main() -> Result<(), Error> {
     if let Some(out) = args.out.to_owned() {
         // TODO: setup a constant size buffer and read/write that many bytes at a time to prevent
         // locking up large amounts of system ram running on a large file.
-        let mut contents;
+        let contents = {
-        {
+            let mut c;
-            // open readfile after this line
             let mut f = OpenOptions::new()
                 .read(true)
                 .open(&pick)
                 .expect("unable to open readfile");
             let m = metadata(&pick).expect("unable to read metadata");
-            contents = vec![0; m.len() as usize];
+            c = vec![0; m.len() as usize];
-            f.read(&mut contents).expect("buffer overflow");
+            f.read(&mut c).expect("buffer overflow");
-        } // readfile closes here due to falling out of scope
+            c
-        let contents = contents; // remove mutability
+        };
         {
-            // open outfile after this line
             let mut f = OpenOptions::new()
                 .write(true)
                 .create(true)
                 .open(out.as_str())
                 .expect("unable to open outfile");
-            f.set_len(0u64).expect("unable to truncate file"); // just call ftruncate() on the poor
+            f.set_len(0u64).expect("unable to truncate file");
-                                                               // thing
             f.write_all(&contents).expect("unable to write to outfile");
-            f.flush().expect(
+            f.flush()
-                "unable to flush outfile (if this happens something has gone *terribly* wrong)",
+                .expect("unable to flush outfile (something has gone comically wrong)");
-            );
+        }
-        } // outfile closes here due to falling out of scope
     } else {
         println!("{}", pick.display());
     }