Move some unsafe code and add error implementations

Cargo.toml

@@ -3,14 +3,23 @@ name = "md2pdf"
 version = "0.0.1"
 authors = ["Thomas Forgione <thomas@forgione.fr>"]
 description = "A small utility to convert markdown files to pdf exploiting tectonic."
-edition = "2018"
+edition = "2021"
 license = "MIT"
 repository = "https://gitea.tforgione.fr/tforgione/md2pdf"
 readme = "README.md"
+cargo = "1.64"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-tectonic = "0.1.11"
-pulldown-cmark = "0.5.2"
-clap = "2.33.0"
+tectonic = "0.5.2"
+pulldown-cmark = "0.5.3"
+clap = { version = "4.0.7", features = ["cargo"] }
+
+[lib]
+name = "md2pdf"
+path = "src/lib.rs"
+
+[[bin]]
+name = "md2pdf"
+path = "src/main.rs"

src/lib.rs

@@ -82,7 +82,7 @@ pub fn markdown_to_latex(markdown: String) -> String {
             Event::Start(Tag::Image(_, path, title)) => {
                 output.push_str("\\begin{figure}\n");
                 output.push_str("\\centering\n");
-                output.push_str("\\includegraphics[width=\\textwidth]{");;
+                output.push_str("\\includegraphics[width=\\textwidth]{");
                 output.push_str(&*path);
                 output.push_str("}\n");
                 output.push_str("\\caption{");

src/main.rs

@@ -1,8 +1,10 @@
 use std::fs::File;
 use std::io::{Read, Write};
 use std::process::exit;
+use std::path::PathBuf;
+use std::ffi::OsStr;
 
-use clap::{crate_authors, crate_description, crate_name, crate_version, App, Arg};
+use clap::{crate_authors, crate_description, crate_name, crate_version, Command, Arg};
 
 use md2pdf::{markdown_to_latex, markdown_to_pdf};
 
@@ -20,41 +22,71 @@ macro_rules! unwrap {
 
 fn main() {
 
-    let matches = App::new(crate_name!())
+    let matches = Command::new(crate_name!())
         .bin_name(crate_name!())
         .version(crate_version!())
         .author(crate_authors!("\n"))
         .about(crate_description!())
-        .arg(Arg::with_name("INPUT")
+        .arg(Arg::new("INPUT")
              .long("input")
-             .short("i")
+             .short('i')
              .help("Input markdown files")
              .required(true)
-             .takes_value(true))
-        .arg(Arg::with_name("OUTPUT")
+             .value_parser(clap::value_parser!(PathBuf))
+            )
+        .arg(Arg::new("OUTPUT")
              .long("output")
-             .short("o")
+             .short('o')
              .help("Output tex or pdf file")
              .required(true)
-             .takes_value(true))
+             .value_parser(clap::value_parser!(PathBuf))
+            )
         .get_matches();
 
+    let input_path = matches.get_one::<PathBuf>("INPUT").unwrap();
     let mut content = String::new();
-    let mut input = unwrap!(File::open(matches.value_of("INPUT").unwrap()), "couldn't open input file");
+    let mut input = unwrap!(File::open(input_path), "couldn't open input file");
     unwrap!(input.read_to_string(&mut content), "couldn't read file content");
 
-    let output_path = matches.value_of("OUTPUT").unwrap();
+    let output_path = matches.get_one::<PathBuf>("OUTPUT").unwrap();
+    let output_path_ext = output_path.extension().and_then(OsStr::to_str);
     let mut output = unwrap!(File::create(output_path), "couldn't open output file");
 
-    if output_path.ends_with(".tex") {
+    match output_path_ext {
+        Some("tex") => {
             let tex = markdown_to_latex(content);
             unwrap!(output.write(tex.as_bytes()), "couldn't write output file");
-    } else if output_path.ends_with(".pdf") {
-        let data = unwrap!(markdown_to_pdf(content), "error while compiling latex, this is most likely a bug");
-        unwrap!(output.write(&data), "coudln't write output file");
-    } else {
-        eprintln!("unknown file format for output: {}", output_path);
+        },
+        Some("pdf") => {
+            match markdown_to_pdf(content) {
+                Ok(data) => {
+                    match output.write(&data) {
+                        Ok(_) => {
+                            exit(0);
+                        },
+                        Err(error) => {
+                            eprintln!(
+                                "error while writing file: {}", error
+                            );
+                            exit(1);
+                        },
+                    }
+                },
+                Err(error) => {
+                    eprintln!(
+                        "error while compiling latex: {}", error.description()
+                    );
                     exit(1);
                 }
-
+            }
+        },
+        Some(ext) => {
+            eprintln!("unknown file format ({}) for output: {}", ext, output_path.display());
+            exit(1);
+        },
+        None => {
+            eprintln!("unknown file format for output: {}", output_path.display());
+            exit(1);
+        },
+    }
 }