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moby--moby/utils/flags.go
Michal Minar 8a785792cd Exit with non-zero code on first argument parsing error
Ignoring return value of ParseFlags leads to exit code 0 if bad
arguments are supplied. This patch makes sure that subcommands exit
with non-zero code in such a case.

Signed-off-by: Michal Minar <miminar@redhat.com>
2015-01-06 13:46:38 +01:00

41 lines
1.1 KiB
Go

package utils
import (
"fmt"
"os"
flag "github.com/docker/docker/pkg/mflag"
)
// ParseFlags is a utility function that adds a help flag if withHelp is true,
// calls cmd.Parse(args) and prints a relevant error message if there are
// incorrect number of arguments. It returns error only if error handling is
// set to ContinueOnError and parsing fails. If error handling is set to
// ExitOnError, it's safe to ignore the return value.
// TODO: move this to a better package than utils
func ParseFlags(cmd *flag.FlagSet, args []string, withHelp bool) error {
var help *bool
if withHelp {
help = cmd.Bool([]string{"#help", "-help"}, false, "Print usage")
}
if err := cmd.Parse(args); err != nil {
return err
}
if help != nil && *help {
cmd.Usage()
// just in case Usage does not exit
os.Exit(0)
}
if str := cmd.CheckArgs(); str != "" {
if withHelp {
if os.Args[0] == cmd.Name() {
str += ". See '" + os.Args[0] + " --help'"
} else {
str += ". See '" + os.Args[0] + " " + cmd.Name() + " --help'"
}
}
fmt.Fprintf(cmd.Out(), "docker: %s.\n", str)
os.Exit(1)
}
return nil
}