+ hg -q help
basic hg commands (use -v for long list):

 add      add the specified files on the next commit
 clone    make a copy of an existing repository
 commit   commit the specified files or all outstanding changes
 diff     diff working directory (or selected files)
 init     create a new repository in the current directory
 log      show the revision history of the repository or a single file
 pull     pull changes from the specified source
 push     push changes to the specified destination
 remove   remove the specified files on the next commit
 serve    export the repository via HTTP
 status   show changed files in the working directory
 update   update or merge working directory
+ hg add -h
hg add: option -h not recognized
hg add [files]

add the specified files on the next commit
+ hg help diff
hg diff [-r A] [-r B] [files]

 -r --rev 
   revision

diff working directory (or selected files)
+ hg help foo
hg: unknown command foo
+ hg -q commands
hg: unknown command 'commands'
basic hg commands (use -v for long list):

 add      add the specified files on the next commit
 clone    make a copy of an existing repository
 commit   commit the specified files or all outstanding changes
 diff     diff working directory (or selected files)
 init     create a new repository in the current directory
 log      show the revision history of the repository or a single file
 pull     pull changes from the specified source
 push     push changes to the specified destination
 remove   remove the specified files on the next commit
 serve    export the repository via HTTP
 status   show changed files in the working directory
 update   update or merge working directory
+ exit 0