Thomas Pelletier
38 lines
742 B
Go
38 lines
742 B
Go
package cli
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import (
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"flag"
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"fmt"
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"io"
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"os"
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)
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type ConvertFn func(r io.Reader, w io.Writer) error
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func Execute(usage string, fn ConvertFn) {
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flag.Usage = func() { fmt.Fprintf(os.Stderr, usage) }
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flag.Parse()
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os.Exit(processMain(flag.Args(), os.Stdin, os.Stdout, os.Stderr, fn))
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}
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func processMain(files []string, input io.Reader, output, error io.Writer, f ConvertFn) int {
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err := run(files, input, output, f)
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if err != nil {
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fmt.Fprintln(error, err.Error())
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return -1
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}
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return 0
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}
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func run(files []string, input io.Reader, output io.Writer, convert ConvertFn) error {
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if len(files) > 0 {
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f, err := os.Open(files[0])
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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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input = f
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}
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return convert(input, output)
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}
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