Greet users who run `typst` for the first time (#5210)

1 files changed, 66 insertions, 0 deletions

diff --git a/crates/typst-cli/src/greet.rs b/crates/typst-cli/src/greet.rs
new file mode 100644
index 00000000..01f273fc
--- /dev/null
+++ b/crates/typst-cli/src/greet.rs
@@ -0,0 +1,66 @@
+use std::io::{self, Read};
+
+/// This is shown to users who just type `typst` the first time.
+#[rustfmt::skip]
+const GREETING: &str = color_print::cstr!("\
+<s>Welcome to Typst, we are glad to have you here!</> ❤️
+
+If you are new to Typst, <s>start with the tutorial</> at \
+<u>https://typst.app/docs/tutorial/</>. To get a quick start with your first \
+project, <s>choose a template</> on <u>https://typst.app/universe/</>.
+
+Here are the <s>most important commands</> you will be using:
+
+- Compile a file once: <c!>typst compile file.typ</>
+- Compile a file on every change: <c!>typst watch file.typ</>
+- Set up a project from a template: <c!>typst init @preview/<<TEMPLATE>></>
+
+Learn more about these commands by running <c!>typst help</>.
+
+If you have a question, we and our community would be glad to help you out on \
+the <s>Typst Forum</> at <u>https://forum.typst.app/</>.
+
+Happy Typsting!
+");
+
+/// Greets (and exists) if not yet greeted.
+pub fn greet() {
+    let Some(data_dir) = dirs::data_dir() else { return };
+    let path = data_dir.join("typst").join("greeted");
+
+    let prev_greet = std::fs::read_to_string(&path).ok();
+    if prev_greet.as_deref() == Some(crate::typst_version()) {
+        return;
+    };
+
+    std::fs::write(&path, crate::typst_version()).ok();
+    print_and_exit(GREETING);
+}
+
+/// Prints a colorized and line-wrapped message.
+fn print_and_exit(message: &'static str) -> ! {
+    // Abuse clap for line wrapping ...
+    let err = clap::Command::new("typst")
+        .max_term_width(80)
+        .help_template("{about}")
+        .about(message)
+        .try_get_matches_from(["typst", "--help"])
+        .unwrap_err();
+    let _ = err.print();
+
+    // Windows users might have double-clicked the .exe file and have no chance
+    // to read it before the terminal closes.
+    if cfg!(windows) {
+        pause();
+    }
+
+    std::process::exit(err.exit_code());
+}
+
+/// Waits for the user.
+#[allow(clippy::unused_io_amount)]
+fn pause() {
+    eprintln!();
+    eprintln!("Press enter to continue...");
+    io::stdin().lock().read(&mut [0]).unwrap();
+}