print some more handy info in trace logs

CHANGELOG.md

@@ -7,7 +7,8 @@ Dates are given in YYYY-MM-DD format.
 - Fixed PowerShell output regression introduced in v0.2.13, whoops
 #### Other
 - Nicer version output: `fif -V` reports "fif v0.3.2" (instead of just "fif 0.3.2" without the "v"), and `fif --version`
-  reports `fif v0.3.2 (XDG-Mime backend)`, or whatever backend you're using.
+  reports `fif v0.3.2 (XDG-Mime backend)`, or whatever backend you're using
+- fif's trace output now includes its version, backend, operating system, and architecture
 
 ### v0.3.1 (2021-07-06)
 #### Features

src/main.rs

@@ -35,6 +35,7 @@ use crate::formats::{Format, PowerShell, Shell};
 use crate::mime_db::MimeDb;
 use crate::parameters::{OutputFormat, ScanOpts};
 use std::collections::BTreeSet;
+use crate::utils::{clap_long_version, os_name};
 
 mod findings;
 mod formats;
@@ -71,7 +72,7 @@ fn main() {
 		// .target(env_logger::Target::Stdout) // log to stdout rather than stderr
 		.init();
 
-	// trace!("fif {}", CLAP_LONG_VERSION.get().unwrap());
+	trace!("fif {}, running on {} {}", clap_long_version(), std::env::consts::ARCH, os_name());
 	trace!("Initialise mimetype database");
 	init_db();
 

src/utils.rs

@@ -30,3 +30,23 @@ pub fn clap_version() -> &'static str { CLAP_VERSION.get_or_init(|| format!("v{}
 pub fn clap_long_version() -> &'static str {
 	CLAP_LONG_VERSION.get_or_init(|| format!("v{} ({} backend)", VERSION.unwrap_or("???"), BACKEND))
 }
+
+/// Returns the name of the target operating system, like "Windows" or "macOS". Won't account for things like Wine or
+/// Linuxulator.
+pub fn os_name() -> String {
+	use std::env::consts::OS;
+	match OS {
+		"ios" => "iOS".into(),
+		"macos" => "macOS".into(),
+		"freebsd" => "FreeBSD".into(),
+		"openbsd" => "OpenBSD".into(),
+		"netbsd" => "NetBSD".into(),
+		"vxworks" => "VxWorks".into(),
+		_ => {
+			// generic case: return consts::OS with the first letter in uppercase ("linux" -> "Linux")
+			let mut os_upper = String::from(OS);
+			os_upper.get_mut(0..1).map(|first| first.make_ascii_uppercase());
+			os_upper
+		}
+	}
+}