add util: write

README.md

@@ -122,6 +122,7 @@ Because it is a FAQ, the major differences between this project and uutils are:
  - [x] touch
  - [x] tty
  - [x] unlink
+ - [x] write
 
 ## Stage 1 - Rough draft
 
@@ -216,7 +217,6 @@ Because it is a FAQ, the major differences between this project and uutils are:
  - [ ] talk
  - [ ] time
  - [ ] timeout
- - [ ] write
 
 ## Testing
 

plib/src/curuser.rs

@@ -0,0 +1,54 @@
+//
+// Copyright (c) 2024 Jeff Garzik
+//
+// This file is part of the posixutils-rs project covered under
+// the MIT License.  For the full license text, please see the LICENSE
+// file in the root directory of this project.
+// SPDX-License-Identifier: MIT
+//
+
+extern crate libc;
+use std::ffi::CStr;
+
+pub fn login_name() -> String {
+    let username = unsafe {
+        // Call getlogin to get the username as a *mut c_char
+        let c_str = libc::getlogin();
+
+        // Check if the pointer is not null
+        if c_str.is_null() {
+            panic!("Failed to get login name");
+        }
+
+        // Convert the *mut c_char to a &CStr
+        let c_str = CStr::from_ptr(c_str);
+
+        // Convert the &CStr to a Rust String
+        match c_str.to_str() {
+            Ok(s) => s.to_owned(), // Successfully converted CStr to Rust String
+            Err(e) => panic!("Failed to convert login name to a Rust String: {}", e),
+        }
+    };
+
+    username
+}
+
+pub fn tty() -> String {
+    // Try to get the tty name from STDIN, STDOUT, STDERR in that order
+    for fd in [libc::STDIN_FILENO, libc::STDOUT_FILENO, libc::STDERR_FILENO].iter() {
+        unsafe {
+            let c_str = libc::ttyname(*fd);
+
+            if !c_str.is_null() {
+                let c_str = CStr::from_ptr(c_str);
+
+                return match c_str.to_str() {
+                    Ok(s) => s.to_owned(),
+                    Err(e) => panic!("Failed to convert tty name to a Rust String: {}", e),
+                };
+            }
+        }
+    }
+
+    panic!("Failed to get tty name from any file descriptor");
+}

plib/src/lib.rs

@@ -7,6 +7,7 @@
 // SPDX-License-Identifier: MIT
 //
 
+pub mod curuser;
 pub mod group;
 pub mod io;
 pub mod lzw;

users/Cargo.toml

@@ -11,8 +11,9 @@ plib = { path = "../plib" }
 clap.workspace = true
 gettext-rs.workspace = true
 libc.workspace = true
-syslog = "6.1"
 atty.workspace = true
+chrono.workspace = true
+syslog = "6.1"
 
 [[bin]]
 name = "id"
@@ -38,3 +39,7 @@ path = "src/pwd.rs"
 name = "tty"
 path = "src/tty.rs"
 
+[[bin]]
+name = "write"
+path = "src/write.rs"
+

users/src/logname.rs

@@ -7,28 +7,10 @@
 // SPDX-License-Identifier: MIT
 //
 
-extern crate libc;
-use std::ffi::CStr;
+extern crate plib;
 
 fn main() {
-    let username = unsafe {
-        // Call getlogin to get the username as a *mut c_char
-        let c_str = libc::getlogin();
-
-        // Check if the pointer is not null
-        if c_str.is_null() {
-            panic!("Failed to get login name");
-        }
-
-        // Convert the *mut c_char to a &CStr
-        let c_str = CStr::from_ptr(c_str);
-
-        // Convert the &CStr to a Rust String
-        match c_str.to_str() {
-            Ok(s) => s.to_owned(), // Successfully converted CStr to Rust String
-            Err(e) => panic!("Failed to convert login name to a Rust String: {}", e),
-        }
-    };
+    let username = plib::curuser::login_name();
 
     println!("{}", username);
 }

users/src/tty.rs

@@ -8,8 +8,7 @@
 //
 
 extern crate atty;
-extern crate libc;
-use std::ffi::CStr;
+extern crate plib;
 
 fn main() {
     let is_tty = atty::is(atty::Stream::Stdin);
@@ -18,24 +17,7 @@ fn main() {
         std::process::exit(1);
     }
 
-    let ttyname = unsafe {
-        // Call getlogin to get the username as a *mut c_char
-        let c_str = libc::ttyname(libc::STDIN_FILENO);
-
-        // Check if the pointer is not null
-        if c_str.is_null() {
-            panic!("Failed to get tty name");
-        }
-
-        // Convert the *mut c_char to a &CStr
-        let c_str = CStr::from_ptr(c_str);
-
-        // Convert the &CStr to a Rust String
-        match c_str.to_str() {
-            Ok(s) => s.to_owned(), // Successfully converted CStr to Rust String
-            Err(e) => panic!("Failed to convert tty name to a Rust String: {}", e),
-        }
-    };
+    let ttyname = plib::curuser::tty();
 
     println!("{}", ttyname);
 }