fix(cli): bump open files limit on macOS and Linux

This automatically bumps the maximum number of open files (NOFILE) to the hard limit.
It prevents 'Too many open files (os error 24)' which happens easily on macOS due to its low default soft limit (256).

Fixes #1248

Author: mre

Cargo.lock

@@ -56,6 +56,7 @@ tokio-stream = "0.1.18"
 toml = "1.0.6"
 url = "2.5.8"
 quick-junit = "0.5.2"
+rlimit = "0.11.0"
 
 
 [dev-dependencies]

lychee-bin/Cargo.toml

@@ -115,6 +115,13 @@ enum ExitCode {
 const LYCHEEIGNORE_COMMENT_MARKER: &str = "#";
 
 fn main() -> Result<()> {
+    // Increase the maximum number of open files on macOS and Linux.
+    // This is helpful because lychee opens many files concurrently during
+    // link extraction and checking, which can exceed the default limit
+    // of 256 open files on macOS. See https://github.com/lycheeverse/lychee/issues/1248
+    #[cfg(any(target_os = "macos", target_os = "linux"))]
+    let _ = rlimit::increase_nofile_limit(u64::MAX);
+
     // std::process::exit doesn't guarantee that all destructors will be run,
     // therefore we wrap the main code in another function to ensure that.
     // See: https://doc.rust-lang.org/stable/std/process/fn.exit.html