Add option to specify [START,END) lines

1 files changed, 6 insertions, 4 deletions

diff --git a/internal/options/options.go b/internal/options/options.go
index b00d3f9..d01ba83 100644
--- a/internal/options/options.go
+++ b/internal/options/options.go
@@ -7,9 +7,10 @@ import (
 
 type Options struct {
 	// Input file
-	InputFile     string
-	MaxFileBuffer int
-	NextLine      int64
+	InputFile          string
+	MaxFileBuffer      int
+	StartLineInclusive int64
+	EndLineExclusive   int64
 
 	// Website visits
 	NumWorkers  int
@@ -25,7 +26,8 @@ type Options struct {
 func Parse() (opts Options) {
 	flag.StringVar(&opts.InputFile, "i", "", "input file, one domain name per line")
 	flag.IntVar(&opts.MaxFileBuffer, "b", 512, "max bytes to read from input file at once in MiB")
-	flag.Int64Var(&opts.NextLine, "n", 0, "next line to start reading the input file from")
+	flag.Int64Var(&opts.StartLineInclusive, "s", 0, "first line to read in input file, inclusive and zero-based index")
+	flag.Int64Var(&opts.EndLineExclusive, "e", 0, "last line to read in input file, exclusive and zero-based; 0 to disable")
 
 	flag.IntVar(&opts.NumWorkers, "w", 2, "number of parallel workers")
 	flag.DurationVar(&opts.Timeout, "t", 10*time.Second, "timeout for each website visit")