Re: PATCH: 3.1.4: autocd to directory in $PATH

["Bart Schaefer" <schaefer@xxxxxxxxxxxxxxxx>]

On Oct 3,  5:30pm, Peter Stephenson wrote:
} Subject: PATCH: 3.1.4: autocd to directory in $PATH
}
} at the moment it looks to me like nothing other than the full
} stat() horror would be a really worthwhile improvement on
[...]
} ***************
} *** 1489,1494 ****
} --- 1502,1509 ----
}   	    char *cmdarg = (char *) peekfirst(args);
}   
}   	    hn = cmdnamtab->getnode(cmdnamtab, cmdarg);
} + 	    if (hn && !isreallycom((Cmdnam)hn))
} + 		hn = NULL;
}   	    if (!hn && isset(HASHCMDS) && strcmp(cmdarg, "..")) {
}   		for (s = cmdarg; *s && *s != '/'; s++);
}   		if (!*s)
		    hn = (HashNode) hashcmd(cmdarg, pathchecked);

(One more line of context added for clarity.)

I haven't actually walked through this with a debugger, but it looks to
me as though hn = NULL at that point is going to trigger the call to
hashcmd(cmdarg, pathchecked), which in turn is going to call iscom() a
second time; so you end up stat()ing the directory twice.  Perhaps

 	    if (hn && !isreallycom((Cmdnam)hn))
 		hn = NULL;
 	    else if (!hn && isset(HASHCMDS) && strcmp(cmdarg, "..")) {
            ^^^^
would be better?

Also, what about removing the improperly hashed directory from cmdnamtab
once you've discovered that it isn't a command?  That would (I think) get
any real command with the same name put into the table the next time that
name was used, so that you'll never needlessly stat() again.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com