38 lines
963 B
Go
38 lines
963 B
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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// Package lineread reads lines from files. It's not fancy, but it got repetitive.
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package lineread
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import (
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"bufio"
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"io"
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"os"
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)
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// File opens name and calls fn for each line. It returns an error if the Open failed
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// or once fn returns an error.
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func File(name string, fn func(line []byte) error) error {
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f, err := os.Open(name)
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if err != nil {
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return err
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}
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defer f.Close()
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return Reader(f, fn)
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}
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// Reader calls fn for each line.
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// If fn returns an error, Reader stops reading and returns that error.
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// Reader may also return errors encountered reading and parsing from r.
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// To stop reading early, use a sentinel "stop" error value and ignore
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// it when returned from Reader.
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func Reader(r io.Reader, fn func(line []byte) error) error {
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bs := bufio.NewScanner(r)
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for bs.Scan() {
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if err := fn(bs.Bytes()); err != nil {
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return err
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}
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}
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return bs.Err()
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}
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