Exa: Display group column automatically when Group differs from User

[coder543]

When the User and Group columns have a different value on one or more files, it would be nice to have the group column automatically printed. This would make it so _most_ of the time, you never see the Group column, but you also don't have to worry about the Group column being different and hidden from view.

This might be challenging if the output is being printed eagerly, rather than traversing the directory entirely before outputting text.

[huxi]

One could do something similar with the User column and only print it if at least one file has a different user than the current user.

[ogham]

You know, that's not a bad idea. The reason exa doesn't display the group column by default is that 99.99% of the time it just holds the same value as the user column — which is going to either be a group with the same name as the user, or whatever that user's default group is. The only times it's useful are when it differs from the default, and exa could just automate that.

@huxi: All the values get put into a table before they're displayed, and that has to measure the width of each column, so we'll have stat-ted every file by the time it gets displayed.