commit 3e3c4e4d6ed5b572ca2b09c8dc7f5bc3bd86e554
Author: Harald Hoyer <harald@hoyer.xyz>
Date:   Thu Mar 21 12:48:09 2024 +0100

    initial commit
    
    Signed-off-by: Harald Hoyer <harald@hoyer.xyz>

diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..03071a3
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1 @@
+src/main.rs text filter=rot8000
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ea8c4bf
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/target
diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 0000000..9fc021d
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,54 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aho-corasick"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "memchr"
+version = "2.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "523dc4f511e55ab87b694dc30d0f820d60906ef06413f93d4d7a1385599cc149"
+
+[[package]]
+name = "regex"
+version = "1.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b62dbe01f0b06f9d8dc7d49e05a0785f153b00b2c227856282f671e0318c9b15"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "86b83b8b9847f9bf95ef68afb0b8e6cdb80f498442f5179a29fad448fcc1eaea"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c08c74e62047bb2de4ff487b251e4a92e24f48745648451635cec7d591162d9f"
+
+[[package]]
+name = "rot8000"
+version = "0.1.0"
+dependencies = [
+ "regex",
+]
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..733f4c0
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "rot8000"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+regex = "1.10"
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..7992936
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,57 @@
+/*!
+To be used as a git smudge filter,
+to replace email addresses in a file with a scrambled version of the email address
+
+```toml
+[filter "rot8000"]
+    smudge = /home/foo/.cargo/bin/rot8000
+    clean = /home/foo/.cargo/bin/rot8000
+```
+
+"grfg123@rknzcyr.bet"
+"grfg456@rknzcyr.bet"
+"grfg456@rknzcyr1.bet"
+ !*/
+
+use regex::{Captures, Regex, Replacer};
+use std::io::stdin;
+struct Rot8000;
+
+impl Replacer for Rot8000 {
+    /// Replace the matched text with a replacement.
+    /// 
+    /// Should have implemented a true unicode rot13, but I was lazy
+    fn replace_append(&mut self, caps: &Captures<'_>, dst: &mut String) {
+        for c in caps[0].chars() {
+            if c.is_ascii() {
+                // do rot13 for ascii alphanumeric characters
+                let mut c = c as u8;
+                if c.is_ascii_lowercase() {
+                    c = (c - b'a' + 13) % 26 + b'a';
+                } else if c.is_ascii_uppercase() {
+                    c = (c - b'A' + 13) % 26 + b'A';
+                }
+                dst.push(unsafe { char::from_u32_unchecked(c as u32) });
+            } else {
+                dst.push(c);
+            }
+        }
+    }
+}
+
+fn main() {
+    // match only ascii email addresses for now
+    let re =
+        Regex::new(r#""([[[:ascii:]]&&[^"\s\[\]\\]]*?@[[[:ascii:]]&&[^"\s]\[\]\\]*)""#).unwrap();
+
+    let mut line = String::new();
+
+    while let Ok(n) = stdin().read_line(&mut line) {
+        if n == 0 {
+            break;
+        }
+        let result = re.replace(&line, Rot8000);
+        print!("{}", result);
+        line.clear();
+    }
+}