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39 lines
695 B
Go
39 lines
695 B
Go
// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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// See page 12.
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//!+
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// Dup3 prints the count and text of lines that
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// appear more than once in the named input files.
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package main
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import (
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"fmt"
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"io/ioutil"
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"os"
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"strings"
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)
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func main() {
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counts := make(map[string]int)
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for _, filename := range os.Args[1:] {
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data, err := ioutil.ReadFile(filename)
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if err != nil {
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fmt.Fprintf(os.Stderr, "dup3: %v\n", err)
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continue
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}
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for _, line := range strings.Split(string(data), "\n") {
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counts[line]++
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}
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}
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for line, n := range counts {
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if n > 1 {
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fmt.Printf("%d\t%s\n", n, line)
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}
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}
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}
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//!-
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