Add md5sum applet

Cargo.lock

@@ -19,6 +19,15 @@ version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
+[[package]]
+name = "block-buffer"
+version = "0.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "69cce20737498f97b993470a6e536b8523f0af7892a4f928cceb1ac5e52ebe7e"
+dependencies = [
+ "generic-array",
+]
+
 [[package]]
 name = "cc"
 version = "1.0.78"
@@ -76,12 +85,32 @@ dependencies = [
  "roff",
 ]
 
+[[package]]
+name = "crypto-common"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1bfb12502f3fc46cca1bb51ac28df9d618d813cdc3d2f25b9fe775a34af26bb3"
+dependencies = [
+ "generic-array",
+ "typenum",
+]
+
 [[package]]
 name = "data-encoding"
 version = "2.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "23d8666cb01533c39dde32bcbab8e227b4ed6679b2c925eba05feabea39508fb"
 
+[[package]]
+name = "digest"
+version = "0.10.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8168378f4e5023e7218c89c891c0fd8ecdb5e5e4f18cb78f38cf245dd021e76f"
+dependencies = [
+ "block-buffer",
+ "crypto-common",
+]
+
 [[package]]
 name = "errno"
 version = "0.2.8"
@@ -103,6 +132,16 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "generic-array"
+version = "0.14.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bff49e947297f3312447abdca79f45f4738097cc82b06e72054d2223f601f1b9"
+dependencies = [
+ "typenum",
+ "version_check",
+]
+
 [[package]]
 name = "hermit-abi"
 version = "0.1.19"
@@ -155,6 +194,15 @@ version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f051f77a7c8e6957c0696eac88f26b0117e54f52d3fc682ab19397a8812846a4"
 
+[[package]]
+name = "md-5"
+version = "0.10.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6365506850d44bff6e2fbcb5176cf63650e48bd45ef2fe2665ae1570e0f4b9ca"
+dependencies = [
+ "digest",
+]
+
 [[package]]
 name = "os_str_bytes"
 version = "6.4.1"
@@ -207,6 +255,7 @@ dependencies = [
  "clap_mangen",
  "data-encoding",
  "libc",
+ "md-5",
  "sc",
  "termcolor",
  "textwrap",
@@ -243,6 +292,18 @@ dependencies = [
  "smawk",
 ]
 
+[[package]]
+name = "typenum"
+version = "1.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "497961ef93d974e23eb6f433eb5fe1b7930b659f06d12dec6fc44a8f554c0bba"
+
+[[package]]
+name = "version_check"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
+
 [[package]]
 name = "walkdir"
 version = "2.3.2"

Cargo.toml

@@ -13,6 +13,7 @@ clap_complete_nushell = "0.1"
 clap_mangen = "0.2"
 data-encoding = "2.3"
 libc = "0.2"
+md-5 = "0.10.5"
 sc = "0.2"
 termcolor = "1.1"
 textwrap = { version = "0.16", default-features = false, features = ["smawk"] }

README.md

@@ -38,6 +38,7 @@ code between applets, making for an overall smaller binary.
 - hostname
 - link
 - logname
+- md5sum
 - mkfifo
 - mknod
 - mountpoint

src/cmd/md5sum/mod.rs

@@ -0,0 +1,102 @@
+use super::Cmd;
+use clap::{Arg, ArgAction, Command};
+use md5::{Digest, Md5};
+use std::{
+    fmt::Write,
+    fs::File,
+    io::{self, BufRead, BufReader, Read},
+    process, error::Error,
+};
+
+#[derive(Debug, Default)]
+pub struct Md5sum;
+
+impl Cmd for Md5sum {
+    fn cli(&self) -> clap::Command {
+        Command::new("md5sum")
+            .about("compute and check MD5 message digest")
+            .author("Nathan Fisher")
+            .version(env!("CARGO_PKG_VERSION"))
+            .args([
+                Arg::new("check")
+                    .help("read checksums from the FILEs and check them")
+                    .short('c')
+                    .long("check")
+                    .action(ArgAction::SetTrue),
+                Arg::new("file")
+                    .value_name("FILE")
+                    .num_args(1..)
+                    .default_value("-"),
+            ])
+    }
+
+    fn run(&self, matches: Option<&clap::ArgMatches>) -> Result<(), Box<dyn std::error::Error>> {
+        let Some(matches) = matches else {
+            return Err(io::Error::new(io::ErrorKind::Other, "no input").into());
+        };
+        if let Some(files) = matches.get_many::<String>("file") {
+            let mut erred = 0;
+            for f in files {
+                if matches.get_flag("check") {
+                    if f == "-" {
+                        return Err(
+                            io::Error::new(io::ErrorKind::Other, "no file specified").into()
+                        );
+                    }
+                    let fd = File::open(f)?;
+                    let reader = BufReader::new(fd);
+                    for line in reader.lines() {
+                        let line = line?;
+                        let mut split = line.split_whitespace();
+                        let sum = split.next().ok_or::<Box<dyn Error>>(
+                            io::Error::new(io::ErrorKind::Other, "invalid checksum file").into(),
+                        )?;
+                        let file = split.next().ok_or::<Box<dyn Error>>(
+                            io::Error::new(io::ErrorKind::Other, "invalid checksum file").into(),
+                        )?;
+                        let mut hasher = Md5::new();
+                        let mut buf = vec![];
+                        let mut fd = File::open(file)?;
+                        let _s = fd.read_to_end(&mut buf)?;
+                        hasher.update(&buf);
+                        let res = hasher.finalize();
+                        let mut s = String::new();
+                        for c in res {
+                            write!(s, "{c:x}")?;
+                        }
+                        if s.as_str() == sum {
+                            println!("{file}: OK");
+                        } else {
+                            println!("{file}: FAILED");
+                            erred += 1;
+                        }
+                    }
+                } else {
+                    let mut hasher = Md5::new();
+                    let mut buf = vec![];
+                    if f == "-" {
+                        let _s = io::stdin().read_to_end(&mut buf)?;
+                    } else {
+                        let mut fd = File::open(f)?;
+                        let _s = fd.read_to_end(&mut buf)?;
+                    }
+                    hasher.update(&buf);
+                    let res = hasher.finalize();
+                    for c in res {
+                        print!("{c:x}");
+                    }
+                    println!("  {f}");
+                }
+            }
+            if erred > 0 {
+                println!("md5sum: WARNING: {erred} computed checksum did NOT match");
+                process::exit(1);
+            }
+        }
+        Ok(())
+    }
+
+    fn path(&self) -> Option<crate::Path> {
+        Some(crate::Path::UsrBin)
+    }
+}

src/cmd/mod.rs

@@ -29,6 +29,7 @@ mod link;
 mod ln;
 mod logname;
 mod ls;
+mod md5sum;
 mod mkfifo;
 mod mknod;
 mod mktemp;
@@ -93,6 +94,7 @@ pub fn get(name: &str) -> Option<Box<dyn Cmd>> {
         "hostname" => Some(Box::new(hostname::Hostname::default())),
         "link" => Some(Box::new(link::Link::default())),
         "logname" => Some(Box::new(logname::Logname::default())),
+        "md5sum" => Some(Box::new(md5sum::Md5sum::default())),
         "mkfifo" => Some(Box::new(mkfifo::MkFifo::default())),
         "mknod" => Some(Box::new(mknod::MkNod::default())),
         "mktemp" => Some(Box::new(mktemp::MkTemp::default())),
@@ -119,7 +121,7 @@ pub fn get(name: &str) -> Option<Box<dyn Cmd>> {
     }
 }
 
-pub static COMMANDS: [&str; 43] = [
+pub static COMMANDS: [&str; 44] = [
     "base32",
     "base64",
     "basename",
@@ -141,6 +143,7 @@ pub static COMMANDS: [&str; 43] = [
     "hostname",
     "link",
     "logname",
+    "md5sum",
     "mkfifo",
     "mknod",
     "mktemp",