influx-cli/clients/helpers.go

54 lines
1.2 KiB
Go

package clients
import (
"fmt"
"io"
"os"
"strings"
)
// ReadQuery reads a Flux query into memory from a --file argument, args, or stdin
func ReadQuery(filepath string, args []string) (string, error) {
nargs := len(args)
if nargs > 1 {
return "", fmt.Errorf("at most 1 query string can be specified as an argument, got %d", nargs)
}
if nargs == 1 && filepath != "" {
return "", fmt.Errorf("query can be specified as a CLI arg or passed in a file via flag, not both")
}
readFile := func(path string) (string, error) {
queryBytes, err := os.ReadFile(path)
if err != nil {
return "", fmt.Errorf("failed to read query from %q: %w", path, err)
}
return string(queryBytes), nil
}
readStdin := func() (string, error) {
queryBytes, err := io.ReadAll(os.Stdin)
if err != nil {
return "", fmt.Errorf("failed to read query from stdin: %w", err)
}
return string(queryBytes), err
}
if filepath != "" {
return readFile(filepath)
}
if nargs == 0 {
return readStdin()
}
arg := args[0]
// Backwards compatibility.
if strings.HasPrefix(arg, "@") {
return readFile(arg[1:])
} else if arg == "-" {
return readStdin()
} else {
return arg, nil
}
}