diff --git a/pttodoer/Cargo.lock b/pttodoer/Cargo.lock
index c0d7794..8b9016c 100644
--- a/pttodoer/Cargo.lock
+++ b/pttodoer/Cargo.lock
@@ -26,6 +26,55 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "anstream"
+version = "0.6.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "418c75fa768af9c03be99d17643f93f79bbba589895012a80e3452a19ddda15b"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "is_terminal_polyfill",
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "038dfcf04a5feb68e9c60b21c9625a54c2c0616e79b72b0fd87075a056ae1d1b"
+
+[[package]]
+name = "anstyle-parse"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c03a11a9034d92058ceb6ee011ce58af4a9bf61491aa7e1e59ecd24bd40d22d4"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a64c907d4e79225ac72e2a354c9ce84d50ebb4586dee56c82b3ee73004f537f5"
+dependencies = [
+ "windows-sys",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "3.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61a38449feb7068f52bb06c12759005cf459ee52bb4adc1d5a7c4322d716fb19"
+dependencies = [
+ "anstyle",
+ "windows-sys",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.3.0"
@@ -64,6 +113,52 @@ dependencies = [
  "windows-targets",
 ]
 
+[[package]]
+name = "clap"
+version = "4.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90bc066a67923782aa8515dbaea16946c5bcc5addbd668bb80af688e53e548a0"
+dependencies = [
+ "clap_builder",
+ "clap_derive",
+]
+
+[[package]]
+name = "clap_builder"
+version = "4.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae129e2e766ae0ec03484e609954119f123cc1fe650337e155d03b022f24f7b4"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "clap_lex",
+ "strsim",
+]
+
+[[package]]
+name = "clap_derive"
+version = "4.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "528131438037fd55894f62d6e9f068b8f45ac57ffa77517819645d10aed04f64"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "clap_lex"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "98cc8fbded0c607b7ba9dd60cd98df59af97e84d24e49c8557331cfc26d301ce"
+
+[[package]]
+name = "colorchoice"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b6a852b24ab71dffc585bcb46eaf7959d175cb865a7152e35b348d1b2960422"
+
 [[package]]
 name = "core-foundation-sys"
 version = "0.8.6"
@@ -91,6 +186,12 @@ version = "0.14.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e5274423e17b7c9fc20b6e7e208532f9b19825d82dfd615708b70edd83df41f1"
 
+[[package]]
+name = "heck"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
+
 [[package]]
 name = "iana-time-zone"
 version = "0.1.60"
@@ -124,6 +225,12 @@ dependencies = [
  "hashbrown",
 ]
 
+[[package]]
+name = "is_terminal_polyfill"
+version = "1.70.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8478577c03552c21db0e2724ffb8986a5ce7af88107e6be5d2ee6e158c12800"
+
 [[package]]
 name = "itoa"
 version = "1.0.11"
@@ -186,6 +293,7 @@ name = "pttodoer"
 version = "0.1.0"
 dependencies = [
  "chrono",
+ "clap",
  "croner",
  "regex",
  "serde",
@@ -269,6 +377,12 @@ dependencies = [
  "unsafe-libyaml",
 ]
 
+[[package]]
+name = "strsim"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
+
 [[package]]
 name = "syn"
 version = "2.0.61"
@@ -292,6 +406,12 @@ version = "0.2.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "673aac59facbab8a9007c7f6108d11f63b603f7cabff99fabf650fea5c32b861"
 
+[[package]]
+name = "utf8parse"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "711b9620af191e0cdc7468a8d14e709c3dcdb115b36f838e601583af800a370a"
+
 [[package]]
 name = "wasm-bindgen"
 version = "0.2.92"
@@ -355,6 +475,15 @@ dependencies = [
  "windows-targets",
 ]
 
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets",
+]
+
 [[package]]
 name = "windows-targets"
 version = "0.52.5"
diff --git a/pttodoer/Cargo.toml b/pttodoer/Cargo.toml
index 144d2c7..1d86bc5 100644
--- a/pttodoer/Cargo.toml
+++ b/pttodoer/Cargo.toml
@@ -7,6 +7,7 @@ edition = "2021"
 
 [dependencies]
 chrono = "0.4.38"
+clap = { version = "4.4.8", features = ["derive"] }
 croner = "2.0.4"
 regex = "1.10.4"
 serde = { version = "1.0.202", features = [ "serde_derive" ] }
diff --git a/pttodoer/src/main.rs b/pttodoer/src/main.rs
index 4b6b309..437ee1f 100644
--- a/pttodoer/src/main.rs
+++ b/pttodoer/src/main.rs
@@ -4,9 +4,28 @@ use chrono::{DateTime, Local};
 use chrono::naive::NaiveDateTime;
 use regex::Regex;
 use croner;
+use clap::Parser;
 
 fn main() {
-    println!("{:?}", Task::new())
+   let flags = Flags::parse();
+   println!("{}", flags.f());
+}
+
+#[derive(Debug, Parser)]
+struct Flags {
+   #[arg(short = 'f', long = "file", default_value="$PTTODO_FILE")]
+   f: String,
+}
+
+impl Flags {
+   fn f(&self) -> String {
+      if self.f.get(..1) == Some("$") {
+         return std::env::var(
+            self.f.get(1..).unwrap()
+         ).expect("not in env");
+      }
+      self.f.clone()
+   }
 }
 
 #[derive(Debug, serde::Serialize, serde::Deserialize)]
@@ -229,10 +248,6 @@ impl Task {
       }
    }
 
-   fn set(&mut self, k: String, v: String) {
-      self.set_value(k, serde_yaml::Value::String(v));
-   }
-
    fn set_value(&mut self, k: String, v: serde_yaml::Value) {
       self.0.insert(
          serde_yaml::Value::String(k),
@@ -628,6 +643,7 @@ impl TS {
       self.0
    }
 
+   #[allow(dead_code)]
    fn to_string(&self) -> String {
       DateTime::from_timestamp(self.0 as i64, 0)
          .unwrap()