62 lines
1.1 KiB
Go
62 lines
1.1 KiB
Go
package main
|
|
|
|
import (
|
|
"flag"
|
|
"fmt"
|
|
"io"
|
|
"os"
|
|
)
|
|
|
|
func main() {
|
|
// Verify and parse arguments
|
|
op := flag.String("op", "sum", "Operation to be executed")
|
|
column := flag.Int("col", 1, "CSV column on which to execute operation")
|
|
flag.Parse()
|
|
if err := run(flag.Args(), *op, *column, os.Stdout); err != nil {
|
|
fmt.Fprintln(os.Stderr, err)
|
|
os.Exit(1)
|
|
}
|
|
}
|
|
|
|
func run(filenames []string, op string, column int, out io.Writer) error {
|
|
var opFunc statsFunc
|
|
if len(filenames) == 0 {
|
|
return ErrNoFiles
|
|
}
|
|
if column < 1 {
|
|
return fmt.Errorf("%w: %d", ErrInvalidColumn, column)
|
|
}
|
|
|
|
switch op {
|
|
case "sum":
|
|
opFunc = sum
|
|
case "avg":
|
|
opFunc = avg
|
|
default:
|
|
return fmt.Errorf("%w: %s", ErrInvalidOperation, op)
|
|
}
|
|
|
|
consolidate := make([]float64, 0)
|
|
|
|
for _, fname := range filenames {
|
|
f, err := os.Open(fname)
|
|
if err != nil {
|
|
return fmt.Errorf("cannot open file: %w", err)
|
|
}
|
|
|
|
data, err := csv2float(f, column)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if err := f.Close(); err != nil {
|
|
return err
|
|
}
|
|
|
|
consolidate = append(consolidate, data...)
|
|
}
|
|
|
|
_, err := fmt.Fprintln(out, opFunc(consolidate))
|
|
return err
|
|
}
|