2 files changed, 39 insertions, 2 deletions
diff --git a/src/run/builtin.rs b/src/run/builtin.rs
index feba7f9..cdeeffe 100644
--- a/src/run/builtin.rs
+++ b/src/run/builtin.rs
@@ -1,3 +1,5 @@
+use std::{fs::OpenOptions, path::PathBuf};
+
 use super::Builtin;
 use crate::*;
 
@@ -43,8 +45,40 @@ impl Builtin for Re {
     }
 }
 
+pub struct Sink {
+    name: &'static str,
+    append: bool,
+}
+
+impl Builtin for Sink {
+    fn name(&self) -> &str {
+        self.name
+    }
+
+    fn io(
+        &self,
+        args: &[BString],
+        stdin: &mut dyn Read,
+        _stdout: &mut dyn Write,
+    ) -> std::io::Result<()> {
+        let Some(path) = args.get(0) else {
+            // TODO exit code
+            return Ok(());
+        };
+        let path = PathBuf::from(OsStr::from_bytes(path));
+        let mut file = OpenOptions::new()
+            .write(true)
+            .create(true)
+            .append(self.append)
+            .open(path)?;
+        std::io::copy(stdin, &mut file)?;
+        Ok(())
+    }
+}
+
+pub const fn sink(name: &'static str, append: bool) -> Sink {
+    Sink { name, append }
+}
 
 // TODO
 // from" => todo!("read from file"),
-// to" | b"into" => todo!("write into file"),
-// append" => todo!("append to file"),
diff --git a/src/run/mod.rs b/src/run/mod.rs
index 10df604..8eb7ad8 100644
--- a/src/run/mod.rs
+++ b/src/run/mod.rs
@@ -164,6 +164,9 @@ const BUILTINS: &[&'static dyn Builtin] = &[
     &builtin::Clear,
     #[cfg(debug_assertions)]
     &builtin::Re,
+    &builtin::sink("to", false),
+    &builtin::sink("into", false),
+    &builtin::sink("append", true),
 ];
 
 pub struct CommandDispatch {