DefaultLoggingFunc do nothing.

ExecContext executes the given command.

ExecErrPipe executes the given command with a pipe that will be connected to the command's stderr when the command starts.

ExecPipe executes the given command with a pipe that will be connected to the command's stdout when the command starts.

IsHelpCmd this function simply calls RetrieveFlagFromCLI("--help", "") Optionally, a single extra argument of type string can be provided to indicate the short name of the help flag.

IsVersionCmd this function simply calls RetrieveFlagFromCLI("--version", "") Optionally, a single extra argument of type string can be provided to indicate the short name of the version flag.

RetrieveFlag returns value of the given flag from args.

RetrieveFlagFromCLI returns value of the given flag from os.Args.

ShellExec executes the given command by shell, errors.g.

ShellExecContext executes the given command by shell.

ShellExecPipe executes the given command with a pipe that will be connected to the command's stdout and stderr when the command starts.

ErrInvalidCmd represents a invalid command error.

ErrExit error with stdout and stderr.

LoggingFunc callback function for logging command output.