Add expand util. Improve echo.

README.md

@@ -73,7 +73,7 @@ https://github.com/jgarzik/posixutils
  - [ ] ed
  - [x] env
  - [ ] ex
- - [ ] expand
+ - [x] expand
  - [ ] expr
  - [x] false
  - [ ] file

display/src/echo.rs

@@ -19,7 +19,7 @@ use gettextrs::{bind_textdomain_codeset, textdomain};
 use plib::PROJECT_NAME;
 use std::io::{self, Write};
 
-fn translate_str(s: &str) -> String {
+fn translate_str(skip_nl: bool, s: &str) -> String {
     let mut output = String::with_capacity(s.len());
 
     let mut in_bs = false;
@@ -66,7 +66,7 @@ fn translate_str(s: &str) -> String {
         }
     }
 
-    if nl {
+    if nl && !skip_nl {
         output.push_str("\n");
     }
 
@@ -80,7 +80,16 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut args: Vec<String> = std::env::args().collect();
     args.remove(0);
 
-    let echo_str = translate_str(&args.join(" "));
+    let skip_nl = {
+        if args.len() > 0 && (args[0] == "-n") {
+            args.remove(0);
+            true
+        } else {
+            false
+        }
+    };
+
+    let echo_str = translate_str(skip_nl, &args.join(" "));
 
     io::stdout().write_all(echo_str.as_bytes())?;
 

display/tests/integration.rs

@@ -23,4 +23,7 @@ fn echo_test(args: &[&str], expected_output: &str) {
 #[test]
 fn test_echo_basic() {
     echo_test(&["big", "brown", "bear"], "big brown bear\n");
+
+    echo_test(&["-n", "foo", "bar"], "foo bar");
+    echo_test(&["foo", "bar\\c"], "foo bar");
 }

text/Cargo.toml

@@ -16,6 +16,10 @@ topological-sort = "0.2"
 name = "asa"
 path = "src/asa.rs"
 
+[[bin]]
+name = "expand"
+path = "src/expand.rs"
+
 [[bin]]
 name = "head"
 path = "src/head.rs"

text/src/expand.rs

@@ -0,0 +1,179 @@
+//
+// 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 clap;
+extern crate plib;
+
+use clap::Parser;
+use gettextrs::{bind_textdomain_codeset, textdomain};
+use plib::PROJECT_NAME;
+use std::fs;
+use std::io::{self, BufWriter, Read, Write};
+
+/// expand - convert tabs to spaces
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about)]
+struct Args {
+    /// Tab stops, either a single positive decimal integer or a list of tabstops separated by commas.
+    #[arg(short, long)]
+    tablist: Option<String>,
+
+    /// Files to read as input.
+    files: Vec<String>,
+}
+
+enum TabList {
+    UniStop(usize),
+    Stops(Vec<usize>),
+}
+
+fn parse_tablist(tablist: &str) -> Result<TabList, &'static str> {
+    let res = tablist.parse::<usize>();
+    if let Ok(tab) = res {
+        return Ok(TabList::UniStop(tab));
+    }
+
+    let mut v = Vec::new();
+    for token in tablist.split(&[' ', ','][..]) {
+        let n = match token.parse::<usize>() {
+            Ok(val) => val,
+            Err(_e) => return Err("Invalid tab stop in list"),
+        };
+
+        if !v.is_empty() {
+            let last = *v.iter().last().unwrap();
+            if n <= last {
+                return Err("Invalid tab stop order in list");
+            }
+        }
+
+        v.push(n);
+    }
+
+    Ok(TabList::Stops(v))
+}
+
+fn space_out(column: &mut usize, writer: &mut BufWriter<dyn Write>) -> io::Result<()> {
+    *column = *column + 1;
+
+    writer.write_all(b" ")?;
+
+    Ok(())
+}
+
+fn expand_file(tablist: &TabList, filename: &str) -> io::Result<()> {
+    // open file, or stdin
+    let mut file: Box<dyn Read>;
+    if filename == "" {
+        file = Box::new(io::stdin().lock());
+    } else {
+        file = Box::new(fs::File::open(filename)?);
+    }
+
+    let mut raw_buffer = [0; plib::BUFSZ];
+    let mut writer = BufWriter::new(io::stdout());
+    let mut column: usize = 1;
+    let mut cur_stop = 0;
+
+    loop {
+        // read a chunk of file data
+        let n_read = file.read(&mut raw_buffer[..])?;
+        if n_read == 0 {
+            break;
+        }
+
+        // slice of buffer containing file data
+        let buf = &raw_buffer[0..n_read];
+
+        for byte_ref in buf {
+            let byte = *byte_ref;
+            if byte == 0x8 {
+                // backspace
+                writer.write_all(&[byte])?;
+                if column > 1 {
+                    column = column - 1;
+                }
+            } else if byte == '\r' as u8 || byte == '\n' as u8 {
+                writer.write_all(&[byte])?;
+                column = 1;
+            } else if byte != '\t' as u8 {
+                writer.write_all(&[byte])?;
+                column = column + 1;
+            } else {
+                match tablist {
+                    TabList::UniStop(n) => {
+                        while (column % n) != 0 {
+                            space_out(&mut column, &mut writer)?;
+                        }
+                        space_out(&mut column, &mut writer)?;
+                    }
+                    TabList::Stops(tabvec) => {
+                        let last_tab: usize = tabvec[tabvec.len() - 1];
+                        let next_tab = tabvec[cur_stop];
+
+                        if column >= last_tab {
+                            space_out(&mut column, &mut writer)?;
+                        } else {
+                            while column < next_tab {
+                                space_out(&mut column, &mut writer)?;
+                            }
+                            cur_stop = cur_stop + 1;
+                            space_out(&mut column, &mut writer)?;
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    writer.flush()?;
+
+    Ok(())
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // parse command line arguments
+    let mut args = Args::parse();
+
+    textdomain(PROJECT_NAME)?;
+    bind_textdomain_codeset(PROJECT_NAME, "UTF-8")?;
+
+    let tablist = {
+        if let Some(ref tablist) = args.tablist {
+            match parse_tablist(&tablist) {
+                Ok(tl) => tl,
+                Err(e) => {
+                    eprintln!("{}", e);
+                    std::process::exit(1);
+                }
+            }
+        } else {
+            TabList::UniStop(8)
+        }
+    };
+
+    // if no files, read from stdin
+    if args.files.is_empty() {
+        args.files.push(String::new());
+    }
+
+    let mut exit_code = 0;
+
+    for filename in &args.files {
+        match expand_file(&tablist, filename) {
+            Ok(()) => {}
+            Err(e) => {
+                exit_code = 1;
+                eprintln!("{}: {}", filename, e);
+            }
+        }
+    }
+
+    std::process::exit(exit_code)
+}

text/tests/integration.rs

@@ -9,6 +9,15 @@
 
 use plib::{run_test, TestPlan};
 
+fn expand_test_noargs(test_data: &str, expected_output: &str) {
+    run_test(TestPlan {
+        cmd: String::from("expand"),
+        args: Vec::new(),
+        stdin_data: String::from(test_data),
+        expected_out: String::from(expected_output),
+    });
+}
+
 fn head_test(test_data: &str, expected_output: &str) {
     run_test(TestPlan {
         cmd: String::from("head"),
@@ -29,6 +38,12 @@ fn wc_test(args: &[&str], test_data: &str, expected_output: &str) {
     });
 }
 
+#[test]
+fn test_expand_basic() {
+    expand_test_noargs("", "");
+    expand_test_noargs("a\tb\tc\n", "a       b       c\n");
+}
+
 #[test]
 fn test_head_basic() {
     head_test("a\nb\nc\nd\n", "a\nb\nc\nd\n");