Please allow booleans to be set false with no- prefix

[Nuru]

@eparis wrote

Basically, booleans can only take arguments via --bool=[true|false] or for short names -b=[true|false]. You cannot use --bool [true|false] nor can you use the shorthand -b[true|false]

This behavior is unlike any other tool I have encountered. The behavior I am used to and consider "normal" for Unix commands, for boolean options, is:

• For short flags, like -b, the option toggles the default value when present. There is generally no way to affirmatively assert the default value with a short flag, though some commands allow it with the same option in the other case, e.g. -B
• For long flags, like --bool, the named option sets the flag true, and the option with a no- prefix sets the flag false, e.g. --no-bool. The "usage" for such a flag would be something like

-b, --[no-]bool 

See, for just one example, git-merge. (Truthfully, most commands are written so there is just a default value and a flag which toggles the default, with the flag being prefixed with no- when it makes for better style, such as --no-undefined Do not allow undefined values. However, when configuration can come from many sources, a command-line option re-asserting default behavior and overriding the other configuration sources is a valuable feature.)

The current state where a flag with an argument is written -f file but a boolean cannot be written -b true is painfully inconsistent as well as awkward, to the point where other options parsers simply do not allow boolean short flags to take arguments. I suggest that instead you automatically create --bool and --no-bool options for all booleans with long forms and if possible provide some kind of warning against creating a short option that has no effect.

Note: I have no problem allowing --bool=false and I support continuing to allow that as it can make scripting easier. On the other hand, --no-bool=true is just plain confusing and should not be allowed.

[umarcor]

Hi @Nuru! I think that this isssue belongs to spf13/pflag, which is the repo used by cobra to define flags. See, for example spf13/pflag#214, spf13/pflag#213, spf13/pflag#139, spf13/pflag#171...

[jharshman]

@Nuru thanks for submitting your issue. It looks like this has already been brought up in spf13/pflag#214. Going to close this as the spf13/pflag is the appropriate place to track it.