From: Johan Holmberg <holmberg@...>
Date: 2003-06-17T01:13:45+09:00
Subject: File.link error messages ?


Hi !

File.link(from,to) can give an error for a number of reasons.

Sometimes the cause is the 'from' parameter, sometimes 'to' and
sometimes any of them (the system call link(2) doesn't tell which).

The Ruby source looks like:

>    if (link(RSTRING(from)->ptr, RSTRING(to)->ptr) < 0)
>        rb_sys_fail(RSTRING(from)->ptr);

so Ruby assumes that the first parameter is to blame.
This is not always true:

    $ touch foo
    $ ruby -e 'File.link("foo", "bar" * 9999)'
    -e:1:in `link': File name too long - foo (Errno::ENAMETOOLONG)
            from -e:1

When I noted this, my first reaction was to try and fix it, but
after a while I realize that it is a bit tricky to present the
right "offending" argument, and sometimes even inpossible (since
the OS doesn't tell which argument to  blame).

How should this be solved ?

One way would of course be to have both filenames as arguments to
the exception. Is this possible ?

Or is there a better way ?

/Johan Holmberg