scriptx/csv.go

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2023-04-24 01:29:54 +00:00
package scriptx
import (
"encoding/csv"
"errors"
"io"
)
func CSVColumn(name string) func(r io.Reader, w io.Writer) error {
return func(r io.Reader, w io.Writer) error {
cr := csv.NewReader(r)
header, err := cr.Read()
if err != nil {
return err
}
var colIdx = -1
for i, ch := range header {
if ch == name {
colIdx = i
}
}
if colIdx == -1 {
return nil
}
for {
rec, err := cr.Read()
if err != nil {
if errors.Is(err, io.EOF) {
return nil
} else {
return err
}
}
if len(rec) < colIdx {
continue
}
if _, err := io.WriteString(w, rec[colIdx]); err != nil {
return err
}
if _, err := w.Write([]byte{'\n'}); err != nil {
return err
}
}
}
}