50 lines
769 B
Go
50 lines
769 B
Go
package scriptx
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import (
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"encoding/csv"
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"errors"
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"io"
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)
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func CSVColumn(name string) func(r io.Reader, w io.Writer) error {
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return func(r io.Reader, w io.Writer) error {
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cr := csv.NewReader(r)
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cr.FieldsPerRecord = -1
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header, err := cr.Read()
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if err != nil {
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return err
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}
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var colIdx = -1
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for i, ch := range header {
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if ch == name {
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colIdx = i
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}
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}
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if colIdx == -1 {
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return nil
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}
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for {
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rec, err := cr.Read()
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if err != nil {
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if errors.Is(err, io.EOF) {
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return nil
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} else {
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return err
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}
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}
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if len(rec) <= colIdx {
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continue
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}
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if _, err := io.WriteString(w, rec[colIdx]); err != nil {
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return err
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}
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if _, err := w.Write([]byte{'\n'}); err != nil {
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return err
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}
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}
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}
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}
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