AddGlobalFlags explicitly registers flags that libraries (log, verflag, etc.) register against the global flag-sets from “flag”.

InitFlags normalizes, parses, then logs the command line flags.

NewNamedFlagSets create NamedFlagSets.

PrintFlags logs the flags in the flagSet.

PrintSections prints the given names flag sets in sections, with the maximal given column number.

Register adds a flag to local that targets the Value associated with the Flag named globalName in a flag.

WarnWordSepNormalizeFunc changes and warns for flags that contain "_" separators.

WordReplaceNormalizeFunc 转化非标准格式 flag 为标准格式.