Initial commit of Rust date-tally

.gitignore

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+/target

Cargo.toml

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+[package]
+name = "date-tally"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+chrono = "0.4"
+regex = "1"
+chrono-tz = "0.8"

src/main.rs

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+use std::env;
+use std::fs;
+use std::io::{self, BufReader, BufRead};
+//use regex::Regex;
+use chrono::{Duration, DateTime, FixedOffset, NaiveDateTime, TimeZone, Utc};
+use chrono_tz::America::New_York;
+
+fn main() {
+    // Regexes
+    //let sep = Regex::new(r":").unwrap();
+
+    // read file argument or stdin
+    let input = env::args().nth(1);
+    let reader: Box<dyn BufRead> = match input {
+        None => Box::new(BufReader::new(io::stdin())),
+        Some(filename) => Box::new(BufReader::new(fs::File::open(filename).unwrap()))
+    };
+
+    let mut old: DateTime<FixedOffset> = DateTime::from(DateTime::<Utc>::MIN_UTC);
+    let mut new: DateTime<FixedOffset> = DateTime::from(DateTime::<Utc>::MIN_UTC);
+
+    for line in reader.lines() {
+        let l: String = line.unwrap();
+        let (item, timestamp) = l.split_once(':').unwrap();
+
+        let ndt = NaiveDateTime::parse_from_str(&timestamp, "%a %b %e %H:%M:%S %Z %Y").unwrap();
+        let dt  = New_York.from_local_datetime(&ndt).unwrap();
+        let ts: DateTime<FixedOffset> = DateTime::parse_from_rfc3339(&dt.to_rfc3339()).unwrap();
+        if old == DateTime::<Utc>::MIN_UTC {
+            old = ts;
+            continue;
+        } else if new == DateTime::<Utc>::MIN_UTC {
+            new = ts;
+        } else {
+            old = new;
+            new = ts;
+        };
+
+        let dur: Duration = new - old;
+
+        let weeks   = dur.num_weeks();
+        let days    = dur.num_days() - weeks * 7;
+        let hours   = dur.num_hours() - weeks * 7 * 24 - days * 24;
+        let minutes = dur.num_minutes() - weeks * 7 * 24 * 60 - days * 24 * 60 - hours * 60;
+        let seconds = dur.num_seconds() - weeks * 7 * 24 * 60 * 60 
+                                        - days * 24 * 60 * 60 - hours * 60 * 60 - minutes * 60;
+
+        println!("{}: {} weeks, {} days, {} hours, {} minutes, {} seconds", 
+                 item, weeks, days, hours, minutes, seconds);
+    };
+}