unshare: improve implementation

1 files changed, 9 insertions, 15 deletions

diff --git a/src/unshare.rs b/src/unshare.rs
index 2aa2b09..bb72db9 100644
--- a/src/unshare.rs
+++ b/src/unshare.rs
@@ -21,7 +21,7 @@ struct SubIDRange {
 }
 
 fn parse_pid(s: &OsStr) -> Option<libc::uid_t> {
-	s.to_str().and_then(|s| s.parse::<libc::uid_t>().ok())
+	s.to_str().and_then(|s| s.parse().ok())
 }
 
 fn parse_id_range(line: Vec<u8>, uid: &OsStr, username: Option<&OsStr>) -> Option<SubIDRange> {
@@ -33,11 +33,10 @@ fn parse_id_range(line: Vec<u8>, uid: &OsStr, username: Option<&OsStr>) -> Optio
 		return None;
 	}
 
-	if let (Some(start), Some(count)) = (parse_pid(parts[1]), parse_pid(parts[2])) {
-		Some(SubIDRange { start, count })
-	} else {
-		None
-	}
+	let start = parse_pid(parts[1])?;
+	let count = parse_pid(parts[2])?;
+
+	Some(SubIDRange { start, count })
 }
 
 fn read_id_ranges(filename: &Path) -> Result<Vec<SubIDRange>> {
@@ -50,15 +49,10 @@ fn read_id_ranges(filename: &Path) -> Result<Vec<SubIDRange>> {
 	let file = File::open(filename)?;
 	let lines = io::BufReader::new(file).split(b'\n');
 
-	let mut ranges = Vec::new();
-
-	for line in lines {
-		if let Some(range) = parse_id_range(line?, &uidstr, usernamestr) {
-			ranges.push(range);
-		}
-	}
-
-	Ok(ranges)
+	lines
+		.map(|line| Ok(parse_id_range(line?, &uidstr, usernamestr)))
+		.filter_map(Result::transpose)
+		.collect()
 }
 
 #[derive(Debug)]