seach: improve usage text re --preview-match; microoptimize previ…

…ew timeout init

[skip ci]

src/cmd/search.rs

@@ -38,7 +38,7 @@ search options:
  No output is produced.
  --preview-match <arg> Preview the first <arg> matches or all the matches found in
  <arg> milliseconds, whichever occurs first. Returns the preview
- to stderr. Output is still written to stdout.
+ to stderr. Output is still written to stdout or --output as usual.
  -c, --count Return number of matches to stderr.
  --size-limit <mb> Set the approximate size limit (MB) of the compiled
  regular expression. If the compiled expression exceeds this 
@@ -171,8 +171,8 @@ pub fn run(argv: &[&str]) -> CliResult<()> {
  }
 
  let mut preview_match_ctr = 0;
- let start_time = std::time::Instant::now();
  let preview_timeout = std::time::Duration::from_millis(preview_match as u64);
+ let start_time = std::time::Instant::now();
  while rdr.read_byte_record(&mut record)? {
  row_ctr += 1;
  m = sel.select(&record).any(|f| pattern.is_match(f));