Frequently Asked Questions and their answers

6.6. What do I need to know about softlinks?

A softlink is basically a pointer to a file or subdirectory that redirects normal unix subdir tree processing to other places. Let's use some examples to clarify the use of softlinks.

Above, we talked about building the kernel under netbsd environment. Well, if you had made only a 50M /usr partition like I did, there is NOT enough room to untar and build the bsdsyssrc.tgz (kernel). Using softlinks, you can put the bsdsyssrc stuff on your /opt partition (where I put mine) and fake unix into thinking it is in /usr/src/sys.

Here's how to do it:

cd /usr
mkdir src
cd src
ln -s /opt/sys sys

Now do:

ls -laF

and you will see something like:

sys@ -> /opt/sys

Now you can just:

cd /opt
tar xzvfp /dev/rst0

and untar the bsdsyssrc there. It will make a /opt/sys for you. Now if you:

cd /usr/src/sys

you have really done:

cd /opt/sys

Another use for softlinks. I recommend this, actually. I put all my amiga (CBM) header files on tape, then untarred them to /opt/cbm then I made a link:

ln -s /opt/cbm /cbm

Now I can:

cd /cbm

and get to my headers. I also put font files in /cbm/fonts. For example, /cbm/fonts/topaz.c is the output of dumpfont (run that under amigaos) to create a topaz font for kernel compiling. I also have a /cbm/fonts/mach.c for the kernel_font.c.distrib and a cedfont.c for a cedfont I made. In the kernel source tree, I did:

cd /usr/src/sys/arch/amiga/dev
ln -s /cbm/fonts/topaz.c kernel_font.c

And when I build the kernel, it uses topaz.c to make the font for the console. Slick? :-)

I hope you get the idea now. One thing that took me a while to get straight is the ORDER of the names on the ln command line :-) Just remember:

ln -s {ORIGINAL} {LINK}

and alphabetically, ORIGINAL is before LINK :-) (Just like the cp-command)

Matthias Kirschnick 04/15/94