# HG changeset patch
# User Tuomo Valkonen <tuomov@iki.fi>
# Date 1697747705 18000
# Node ID cec573b16b462afccd6bfe3c144562512a03d42f
# Parent  254e1e4bd79517d06421f9759bcb37de0c8535b2
Add command line options for input and output files

diff -r 254e1e4bd795 -r cec573b16b46 README.md
--- a/README.md	Thu Oct 19 15:10:12 2023 -0500
+++ b/README.md	Thu Oct 19 15:35:05 2023 -0500
@@ -6,11 +6,14 @@
 ## Installation and usage
 
 1. Install [Rust](https://www.rust-lang.org) following instructions.
-2. Run `cargo build` to compile the program (optional; the next step does it if needed).
-3. To process a document, use
+2. To compile and install the program (typically in `~/.cargo/bin/`), run
+   ```
+   cargo install --path=.
    ```
-   cargo run < input.tex > output.tex
+   If you would prefer just building or running the program without installing, use `cargo build` or `cargo run`.
+4. To process a document, use
    ```
-   You may also find the built binary under `target/debug/strip-changes-markup`, and copy it to a place that works for you, instead of using `cargo` to run the program.
+   strip-change-markup input.tex -o output.tex
+   ```
 
-   
\ No newline at end of file
+For further options, such as whitespace and comment stripping, use the `--help` argument (`cargo run -- --help` when running through `cargo` without installing).
diff -r 254e1e4bd795 -r cec573b16b46 src/main.rs
--- a/src/main.rs	Thu Oct 19 15:10:12 2023 -0500
+++ b/src/main.rs	Thu Oct 19 15:35:05 2023 -0500
@@ -2,7 +2,8 @@
 #![doc = include_str!("../README.md")]
 
 use std::io;
-use std::io::BufWriter;
+use std::fs::File;
+use std::io::{BufWriter, BufRead, BufReader};
 use std::io::Write;
 use clap::Parser;
 
@@ -14,6 +15,13 @@
     version = env!("CARGO_PKG_VERSION"),
 )]
 struct CommandLineArgs {
+    /// Input file (default is stdin)
+    input : Option<String>,
+
+    /// Output file (defalt is stdout)
+    #[arg(long, short = 'o')]
+    output : Option<String>,
+
     #[arg(long, short = 'c')]
     /// Strip comments
     strip_comments : bool,
@@ -113,12 +121,19 @@
 
 fn main() {
     let cli = CommandLineArgs::parse();
-    let input = io::stdin();
-
+    let input = cli.input.map_or_else(
+        || Box::new(BufReader::new(io::stdin())) as Box<dyn BufRead>,
+        |f| Box::new(BufReader::new(File::open(f).unwrap())) as Box<dyn BufRead>
+    );
+    let output = cli.output.map_or_else(
+        || Box::new(BufWriter::new(io::stdout())) as Box<dyn Write>,
+        |f| Box::new(BufWriter::new(File::create(f).unwrap())) as Box<dyn Write>
+    );
+    
     let mut o = Out {
         only_whitespace : true,
         stored_whitespace : String::new(),
-        output : BufWriter::new(io::stdout()),
+        output,
         stack : Vec::new(),
         whitespace_satisfied : true,
         par_satisfied : true,