Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!umd5!uvaarpa!mcnc!decvax!ucbvax!cbosgd!cbdkc1!pmd
From: pmd@cbdkc1.ATT.COM (Paul Dubuc)
Newsgroups: comp.lang.c
Subject: Re: system
Message-ID: <2824@cbdkc1.ATT.COM>
Date: 2 Feb 88 15:39:16 GMT
References: <127@dcrbg1.UUCP> <1670009@otter.HP.COM> <7@obie.UUCP>
Reply-To: pmd@cbdkc1.UUCP (Paul Dubuc)
Organization: AT&T Bell Laboratories; Columbus, Ohio
Lines: 26

In article <7@obie.UUCP> wes@obie.UUCP (Barnacle Wes) writes:
}On System V, directories are made with the system call mknod(2).
}To make the directory '/usr/fool' with rwxrwxr-x permissions,
}you would use:
}
}	mknod("/usr/fool", 040775, 0);
}
}The mode bits are: 040000: make directory, 0775: permission bits.

It's already been mentioned that System Vr3 has a mkdir() call, but
in the older systems, this still won't do the whole job of making
a directory.  After the mknod(), you need two calls to link() to make
it properly:

	link("/usr/fool", "/usr/fool/.");
	link("/usr", "/usr/fool/..");

This *still* requires the calling program to have super-user permission,
so I think the solution of using a routine that exec's the mkdir comand
is better.  I never understood why making directories was a super user
priviledge.  Can someone enlighten me?  Since they changed it in r3 of
sys V, there must not have been a good reason.


-- 

Paul Dubuc	{ihnp4,cbosgd}!cbdkc1!pmd