[SOLVED] ls strange behavior when i give it `-- ` as argument

Issue

When I execute ls --:

$ls --
a.out       ft_ls.c     ft_ls.h     ft_ls.h.gch libft`

it display the content of the current directory,
but the - alone is interpreted like a directory named '-':

$ls -
ls: -: No such file or directory

and ls --- is illegal flag:

$ls ---
ls: illegal option -- -
usage: ls [-ABCFGHLOPRSTUWabcdefghiklmnopqrstuwx1] [file ...]

and can I know why --- isn't interpreted by default as a file name?

Solution

-- has a special meaning as the marker of "end of options"; whereas --- or - has no such special meaning.

POSIX convention says:

The first -- argument that is not an option-argument should be accepted as a delimiter indicating the end of options. Any following arguments should be treated as operands, even if they begin with the '-' character.

If you are implementing ls then you might be interested in using getopt function and you can easily implement similar option processing as the ls command.

Answered By - P.P