allow reading from stdin

src/logfile/mod.rs

@@ -36,6 +36,10 @@ pub struct LogFile {
 }
 
 impl LogFile {
+    pub fn from_string(content: String) -> Self {
+        Self { content }
+    }
+
     pub fn open<R: Read + Seek>(path: &str, file: R) -> Result<LogFile, ReadError> {
         if path.ends_with(".zip") {
             let mut zip = ZipArchive::new(file)?;

src/main.rs

@@ -1,5 +1,5 @@
 use crate::app::App;
-use crate::error::LogError;
+use crate::error::{LogError, ReadError};
 use crate::logfile::{LogFile, LogLineNumber};
 use crate::logs::ParsedLogs;
 use crate::matcher::{MatchResult, Matcher};
@@ -15,7 +15,7 @@ use rayon::prelude::*;
 use std::borrow::Cow;
 use std::collections::HashMap;
 use std::fs::File;
-use std::io::{BufReader, Stderr, Write};
+use std::io::{read_to_string, stdin, BufReader, Stderr, Write};
 use std::iter::once;
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::RwLock;
@@ -41,6 +41,7 @@ static GLOBAL: Jemalloc = Jemalloc;
 #[derive(Debug, Parser)]
 #[command(version, about, long_about = None)]
 struct Args {
+    /// File to read from, or "-" for stdin
     file: String,
     /// Collect data and exit, intended for profiling
     #[arg(long)]
@@ -51,7 +52,7 @@ struct Args {
 }
 
 fn main() -> MainResult {
-    let args = Args::parse();
+    let args: Args = Args::parse();
 
     if let Some(date_format) = args.date_format.as_deref() {
         let date_format = if date_format.contains('%') {
@@ -67,12 +68,21 @@ fn main() -> MainResult {
             .expect("Set only once");
     }
 
-    let file = File::open(&args.file)?;
-    let file = BufReader::new(file);
-    let log_file = LogFile::open(&args.file, file).map_err(|err| LogError::Read {
-        err,
-        path: args.file,
-    })?;
+    let log_file = if args.file == "-" {
+        let content = read_to_string(stdin()).map_err(|err| LogError::Read {
+            err: ReadError::Io(err),
+            path: args.file,
+        })?;
+        LogFile::from_string(content)
+    } else {
+        let file = File::open(&args.file)?;
+        let file = BufReader::new(file);
+        LogFile::open(&args.file, file).map_err(|err| LogError::Read {
+            err,
+            path: args.file,
+        })?
+    };
+
     let lines: Vec<_> = log_file
         .iter()
         .enumerate()