tar -r on a diskfile/tar arg too long

[Guy Harris]

 > My Fine Manual (SunOS 3.x) says the F option will exclude SCCS 
 >directories, FF will also exclude .o, errs, core and a.out files.
 >
 > Has this changed on SunOS 4.x, or in some other tar ???

Apparently, since the other guy said that in his "tar" the "F" option
specified a file giving a list of file names.  The original V7 "tar"
didn't have *any* "F" flag, and the S5 "tar" still doesn't, as of the
S5R3.1 3B2 source distribution....  Berkeley added the "F" flag you find
in SunOS, and Sun picked it up from there.

>For the record, my `long_list' is approx 100 lines of about 50 characters
>each ( does'nt sound too long to me :-) ).

100 lines of about 50 characters is about 5000 characters.  Earlier
UNIXes had a limit of about 4096 or 5120 characters worth of arguments;
you're close to the limit for those systems.  (Even *earlier* systems
had limits of somewhere around 512 characters, as I remember, but few of
those remain....)

4BSD bumped that to 10240, and later to 20480; I forget what SunOS 3.x
had as its limit.  (Grep for NCARGS in "/usr/include/sys/param.h".) 
SunOS 4.0 boosted it to 0x100000, although the 4.x C shell can't cope with
an argument list that big (the Bourne shell doesn't have quite the same
problem).