new: added functions to get terminal size

.github/workflows/rust.yml

@@ -18,7 +18,7 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: ${{ matrix.rustver }}
-      - run: cargo test
+      - run: cargo test -- --show-output
 
   cover:
     name: Coverage for Rust ${{ matrix.rustver }} on ${{ matrix.os }}

Cargo.toml

@@ -15,4 +15,14 @@ categories = ["text-processing"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-icu = "1.4.0"
+icu = "1.4"
+
+[target.'cfg(unix)'.dependencies]
+libc = "0.2"
+
+[target.'cfg(windows)'.dependencies.windows]
+version = "0.53"
+features = [
+    "Win32_Foundation",
+    "Win32_System_Console",
+]

build.sh

@@ -52,7 +52,7 @@ doc() {
 }
 
 if [[ "$#" == "0" ]]; then
-  clean
+  #clean
   format
   compile
   test

src/lib.rs

@@ -59,7 +59,41 @@
 mod char_buffer;
 mod line_iter;
 mod linebreak;
+mod terminal;
 mod unicode;
 
 pub use line_iter::LineIter;
+pub use terminal::Size;
 pub use unicode::{char_width, is_print, text_width};
+
+/// Returns the column number of the current terminal.
+///
+/// If failing to retrieve the column number, this function returns the
+/// tentative value `80`.
+/// This is because this crate would be used on character output terminals,
+/// and errors occure only in special circumstances such as during CI
+/// execution.
+/// In such circumstances, it is assumed that returning a tentative value would
+/// be beneficial than returning an error.
+pub fn term_cols() -> u16 {
+    match terminal::term_cols() {
+        Ok(cols) => cols,
+        Err(_) => 80,
+    }
+}
+
+/// Returns the size of the current terminal.
+///
+/// If failing to retrieve the column number, this function returns the
+/// tentative size `{ col: 80, row: 24 }`.
+/// This is because this crate would be used on character output terminals,
+/// and errors occure only in special circumstances such as during CI
+/// execution.
+/// In such circumstances, it is assumed that returning a tentative value would
+/// be beneficial than returning an error.
+pub fn term_size() -> Size {
+    match terminal::term_size() {
+        Ok(size) => size,
+        Err(_) => Size { col: 80, row: 24 },
+    }
+}

src/terminal/mod.rs

@@ -0,0 +1,103 @@
+// Copyright (C) 2024 Takayuki Sato. All Rights Reserved.
+// This program is free software under MIT License.
+// See the file LICENSE in this distribution for more details.
+
+/// `Size` is the struct for storing the size of the current terminal.
+#[derive(Debug)]
+pub struct Size {
+    /// The column number of the terminal.
+    pub col: u16,
+    /// The row number of the terminal.
+    pub row: u16,
+}
+
+#[cfg(unix)]
+mod unix;
+#[cfg(unix)]
+pub use self::unix::{term_cols, term_size};
+
+#[cfg(windows)]
+mod windows;
+#[cfg(windows)]
+pub use self::windows::{term_cols, term_size};
+
+#[cfg(not(any(unix, windows)))]
+mod unknown;
+#[cfg(not(any(unix, windows)))]
+pub use self::unknown::{term_cols, term_size};
+
+#[cfg(test)]
+mod test_of_term_cols {
+    use super::*;
+
+    #[cfg(unix)]
+    #[test]
+    fn test_get_terminal_cols() {
+        match term_cols() {
+            Ok(c) => println!("term cols = {}", c),
+            Err(e) => {
+                println!("term cols error = {}", e.to_string());
+                assert_eq!(e.raw_os_error().unwrap(), 25); // NOTTY
+            }
+        }
+    }
+
+    #[cfg(windows)]
+    #[test]
+    fn test_get_terminal_cols() {
+        match term_cols() {
+            Ok(c) => println!("term cols = {}", c),
+            Err(e) => {
+                println!("term cols error = {}", e.to_string());
+                assert_eq!(e.raw_os_error().unwrap() & 0xffff, 6); // Invalid Handler
+            }
+        }
+    }
+
+    #[cfg(not(any(unix, windows)))]
+    #[test]
+    fn test_get_terminal_cols() {
+        match term_cols() {
+            Ok(cols) => assert!(false),
+            Err(e) => assert_eq!(e.kind(), ErrorKind::Unsupported),
+        }
+    }
+}
+
+#[cfg(test)]
+mod test_of_term_size {
+    use super::*;
+
+    #[cfg(unix)]
+    #[test]
+    fn test_get_terminal_size() {
+        match term_size() {
+            Ok(sz) => println!("term size = {} x {}", sz.col, sz.row),
+            Err(e) => {
+                println!("term size error = {}", e.to_string());
+                assert_eq!(e.raw_os_error().unwrap(), 25); // NOTTY
+            }
+        }
+    }
+
+    #[cfg(windows)]
+    #[test]
+    fn test_get_terminal_size() {
+        match term_size() {
+            Ok(sz) => println!("term size = {} x {}", sz.col, sz.row),
+            Err(e) => {
+                println!("term size error = {}", e.to_string());
+                assert_eq!(e.raw_os_error().unwrap() & 0xffff, 6); // Invalid Handler
+            }
+        }
+    }
+
+    #[cfg(not(any(unix, windows)))]
+    #[test]
+    fn test_get_terminal_cols() {
+        match term_cols() {
+            Ok(cols) => assert!(false),
+            Err(e) => assert_eq!(e.kind(), ErrorKind::Unsupported),
+        }
+    }
+}

src/terminal/unix.rs

@@ -0,0 +1,38 @@
+// Copyright (C) 2024 Takayuki Sato. All Rights Reserved.
+// This program is free software under MIT License.
+// See the file LICENSE in this distribution for more details.
+
+use super::Size;
+use libc::{ioctl, winsize, STDOUT_FILENO, TIOCGWINSZ};
+use std::io;
+
+pub fn term_cols() -> Result<u16, io::Error> {
+    let mut ws = winsize {
+        ws_row: 0,
+        ws_col: 0,
+        ws_xpixel: 0,
+        ws_ypixel: 0,
+    };
+    let r = unsafe { ioctl(STDOUT_FILENO, TIOCGWINSZ, &mut ws) };
+    match r {
+        0 => Ok(ws.ws_col as u16),
+        _ => Err(io::Error::last_os_error()),
+    }
+}
+
+pub fn term_size() -> Result<Size, io::Error> {
+    let mut ws = winsize {
+        ws_row: 0,
+        ws_col: 0,
+        ws_xpixel: 0,
+        ws_ypixel: 0,
+    };
+    let r = unsafe { ioctl(STDOUT_FILENO, TIOCGWINSZ, &mut ws) };
+    match r {
+        0 => Ok(Size {
+            col: ws.ws_col as u16,
+            row: ws.ws_row as u16,
+        }),
+        _ => Err(io::Error::last_os_error()),
+    }
+}

src/terminal/unknown.rs

@@ -0,0 +1,14 @@
+// Copyright (C) 2024 Takayuki Sato. All Rights Reserved.
+// This program is free software under MIT License.
+// See the file LICENSE in this distribution for more details.
+
+use super::Size;
+use std::io;
+
+pub fn term_cols() -> Result<u16, io::Error> {
+    Error::new(ErrorKind::Unsupported)
+}
+
+pub fn term_size() -> Result<u16, io::Error> {
+    Error::new(ErrorKind::Unsupported)
+}

src/terminal/windows.rs

@@ -0,0 +1,64 @@
+// Copyright (C) 2024 Takayuki Sato. All Rights Reserved.
+// This program is free software under MIT License.
+// See the file LICENSE in this distribution for more details.
+
+use super::Size;
+use std::io;
+
+use windows::Win32::System::Console::{
+    GetConsoleScreenBufferInfo, GetStdHandle, CONSOLE_CHARACTER_ATTRIBUTES,
+    CONSOLE_SCREEN_BUFFER_INFO, COORD, SMALL_RECT, STD_OUTPUT_HANDLE,
+};
+
+pub fn term_cols() -> Result<u16, io::Error> {
+    let mut bi = CONSOLE_SCREEN_BUFFER_INFO {
+        dwSize: COORD { X: 0, Y: 0 },
+        dwCursorPosition: COORD { X: 0, Y: 0 },
+        wAttributes: CONSOLE_CHARACTER_ATTRIBUTES(0),
+        srWindow: SMALL_RECT {
+            Left: 0,
+            Top: 0,
+            Right: 0,
+            Bottom: 0,
+        },
+        dwMaximumWindowSize: COORD { X: 0, Y: 0 },
+    };
+
+    let h = match unsafe { GetStdHandle(STD_OUTPUT_HANDLE) } {
+        Ok(h) => h,
+        Err(e) => return Err(io::Error::from_raw_os_error(e.code().0)),
+    };
+
+    match unsafe { GetConsoleScreenBufferInfo(h, &mut bi) } {
+        Ok(_) => Ok((bi.srWindow.Right - bi.srWindow.Left + 1) as u16),
+        Err(e) => Err(io::Error::from_raw_os_error(e.code().0)),
+    }
+}
+
+pub fn term_size() -> Result<Size, io::Error> {
+    let mut bi = CONSOLE_SCREEN_BUFFER_INFO {
+        dwSize: COORD { X: 0, Y: 0 },
+        dwCursorPosition: COORD { X: 0, Y: 0 },
+        wAttributes: CONSOLE_CHARACTER_ATTRIBUTES(0),
+        srWindow: SMALL_RECT {
+            Left: 0,
+            Top: 0,
+            Right: 0,
+            Bottom: 0,
+        },
+        dwMaximumWindowSize: COORD { X: 0, Y: 0 },
+    };
+
+    let h = match unsafe { GetStdHandle(STD_OUTPUT_HANDLE) } {
+        Ok(h) => h,
+        Err(e) => return Err(io::Error::from_raw_os_error(e.code().0)),
+    };
+
+    match unsafe { GetConsoleScreenBufferInfo(h, &mut bi) } {
+        Ok(_) => Ok(Size {
+            col: (bi.srWindow.Right - bi.srWindow.Left + 1) as u16,
+            row: (bi.srWindow.Bottom - bi.srWindow.Top + 1) as u16,
+        }),
+        Err(e) => Err(io::Error::from_raw_os_error(e.code().0)),
+    }
+}

tests/terminal_test.rs

@@ -0,0 +1,24 @@
+use linebreak::{term_cols, term_size};
+use std::env;
+
+#[test]
+fn it_should_get_terminal_column_number() {
+    let cols = term_cols();
+    if env::var("CI").is_err() {
+        assert!(cols > 0);
+    } else {
+        assert_eq!(cols, 80);
+    }
+}
+
+#[test]
+fn it_should_get_terminal_size() {
+    let size = term_size();
+    if env::var("CI").is_err() {
+        assert!(size.col > 0);
+        assert!(size.row > 0);
+    } else {
+        assert_eq!(size.col, 80);
+        assert_eq!(size.row, 24);
+    }
+}