how do you apply patches

[Mark Ferraretto]

the subject line says it all.
Here is an example of what I mean :

Submitted-by: vojta at math.berkeley.edu (Paul Vojta)
Posting-number: Volume 3, Issue 46
Archive-name: xdvi/patch1

[Here is a patch I got right after I sent out xdvi.  I have modified
it to update the patchlevel.h file -mcw]

diff -crb xdvi.old/patchlevel.h xdvi/patchlevel.h
*** xdvi.old/patchlevel.h       Fri Mar 10 11:12:44 1989
--- xdvi/patchlevel.h   Fri Mar 10 11:18:49 1989
***************
*** 1 ****
! #define PATCHLEVEL 0
--- 1 ----
! #define PATCHLEVEL 1
diff -crb xdvi.old/pxl_open.c xdvi/pxl_open.c
*** xdvi.old/pxl_open.c Fri Mar 10 11:12:45 1989
--- xdvi/pxl_open.c     Fri Mar 10 11:17:15 1989
***************
*** 94,100 ****
            f = fopen(nm, OPEN_MODE);
        }
        if (f != NULL) {
!           *name = malloc((unsigned) (n - nm));
            Strcpy(*name, nm);
        }
        return(f);
--- 94,100 ----
            f = fopen(nm, OPEN_MODE);
        }
        if (f != NULL) {
!           *name = malloc((unsigned) (n - nm + 1));
            Strcpy(*name, nm);
        }
        return(f);
--
Mike Wexler(wyse!mikew)    Phone: (408)433-1000 x1330
Moderator of comp.sources.x

I don't know if this is one kind of patch or if this is the only kind of patch
can you please let me know the case?  And if there exist more than one kind of 
patch then please let me know how to apply each kind if possible.
Thanks
----------------------------------------------------------------------------
| Mark Ferraretto                       | mferrare at physics.adelaide.edu.au |
| Dept Physics and Mathematical Physics | Phone:    +61 8 228 5428         |
| University of Adelaide                |----------------------------------|