35 lines
636 B
Go
35 lines
636 B
Go
package main
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import (
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"bufio"
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"fmt"
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"os"
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"strconv"
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"strings"
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)
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func main() {
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if len(os.Args) < 2 {
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fmt.Fprintf(os.Stderr, "usage: %s <field-number>", os.Args[0])
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os.Exit(1)
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}
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fieldNum, err := strconv.Atoi(os.Args[1])
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if err != nil || fieldNum < 1 {
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fmt.Fprintln(os.Stderr, "invalid field number:", os.Args[1])
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os.Exit(1)
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}
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scanner := bufio.NewScanner(os.Stdin)
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for scanner.Scan() {
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line := scanner.Text()
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fields := strings.Fields(line)
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if len(fields) >= fieldNum {
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fmt.Println(fields[fieldNum-1])
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}
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}
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if err := scanner.Err(); err != nil {
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fmt.Fprintln(os.Stderr, "error reading input:", err)
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}
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}
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