stty: add handling of special characters

src/uu/stty/Cargo.toml

@@ -18,8 +18,13 @@ path = "src/stty.rs"
 
 [dependencies]
 clap = { workspace = true }
+nix = { workspace = true, features = ["feature", "fs", "term", "ioctl"] }
+phf = { workspace = true }
 uucore = { workspace = true }
-nix = { workspace = true, features = ["term", "ioctl"] }
+
+[build-dependencies]
+phf_codegen = { workspace = true }
+unicode_names2 = "1.3.0"
 
 [[bin]]
 name = "stty"

src/uu/stty/build.rs

@@ -0,0 +1,136 @@
+// spell-checker:ignore tbody
+
+use std::{
+    env,
+    error::Error,
+    fs::{self, File},
+    io::{BufWriter, Write},
+    path::Path,
+    process::ExitCode,
+};
+
+fn main() -> ExitCode {
+    if let Err(bo) = write_perfect_hash_map() {
+        eprintln!("Error occurred while building and writing perfect hash map: {bo:?}");
+
+        ExitCode::FAILURE
+    } else {
+        ExitCode::SUCCESS
+    }
+}
+
+fn write_perfect_hash_map() -> Result<(), Box<dyn Error>> {
+    const NUMBER_OF_VALUE_LINES_IN_PRELUDE: usize = 3_usize;
+
+    // `textContent` value of <tbody> node of the table with the heading
+    // "Table: Circumflex Control Characters in stty"
+    // in https://pubs.opengroup.org/onlinepubs/9799919799/utilities/stty.html
+    let text_content = fs::read_to_string("./circumflex-control-characters.txt")?;
+
+    let mut map = phf_codegen::Map::<u8>::new();
+
+    let mut value_encountered_count = 0_usize;
+
+    let mut peekable = text_content.lines().peekable();
+
+    while let Some(current_line) = peekable.peek().copied() {
+        peekable.next();
+
+        if current_line.is_empty() || current_line == "\u{00A0}" {
+            continue;
+        }
+
+        if value_encountered_count < NUMBER_OF_VALUE_LINES_IN_PRELUDE {
+            if current_line == "Value" {
+                value_encountered_count += 1_usize;
+            }
+
+            continue;
+        }
+
+        if value_encountered_count != NUMBER_OF_VALUE_LINES_IN_PRELUDE {
+            return Err(Box::from("Expectation violated"));
+        }
+
+        let keys = current_line;
+
+        loop {
+            let Some(str) = peekable.next() else {
+                return Err(Box::from("Expectation violated"));
+            };
+
+            if str.is_empty() {
+                continue;
+            }
+
+            let mut encoding_buffer = [0_u8; 4_usize];
+
+            let mut str_chars = str.chars();
+
+            if str_chars.next() != Some('<') || str_chars.next_back() != Some('>') {
+                return Err(Box::from("Expectation violated"));
+            }
+
+            let str_chars_str = str_chars.as_str();
+
+            // Look up value of alias
+            let Some(value_char) = unicode_names2::character(str_chars_str) else {
+                return Err(Box::from("Expectation violated"));
+            };
+
+            let value_encode_str = value_char.encode_utf8(&mut encoding_buffer);
+
+            let value_only_byte = match value_encode_str.as_bytes() {
+                &[ue] => ue,
+                _ => {
+                    return Err(Box::from("Expectation violated"));
+                }
+            };
+
+            let value_only_byte_string = format!("{value_only_byte}_u8");
+
+            let value_only_byte_str = value_only_byte_string.as_str();
+
+            for key in keys.split(",") {
+                let mut key_chars_skip_while = key.chars().skip_while(|&ch| ch == ' ');
+
+                let Some(key_only_char) = key_chars_skip_while.next() else {
+                    return Err(Box::from("Expectation violated"));
+                };
+
+                let None = key_chars_skip_while.next() else {
+                    return Err(Box::from("Expectation violated"));
+                };
+
+                let key_only_char_str = key_only_char.encode_utf8(&mut encoding_buffer);
+
+                match key_only_char_str.as_bytes() {
+                    &[key_only_char_only_byte] => {
+                        map.entry(key_only_char_only_byte, value_only_byte_str);
+                    }
+                    _ => {
+                        return Err(Box::from("Expectation violated"));
+                    }
+                }
+            }
+
+            break;
+        }
+    }
+
+    let display_map = map.build();
+
+    let out_dir = env::var("OUT_DIR")?;
+
+    let path_buf = Path::new(out_dir.as_str()).join("circumflex_control_characters_table.rs");
+
+    let mut buf_writer = BufWriter::new(File::create(path_buf.as_path())?);
+
+    writeln!(
+        &mut buf_writer,
+        "pub static CIRCUMFLEX_CONTROL_CHARACTERS_TABLE_MAP: phf::Map<u8, u8> = {};",
+        display_map
+    )?;
+
+    Ok(())
+}