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- From: seismo!gatech!hpcnof!hpfcla!hpfcdc!rml (Bob Lenk)
- Date: Thu, 8 Jan 87 20:20:47 mst
-
- > From: cbosgd!mark@seismo.css.gov (Mark Horton)
- >
- > While P.1003 does not restrict implementations to SYS_NMLN=9 (including
- > the null) it requires that all 5 fields support the full length.
- > I don't know of any way to increase SYS_NMLN while maintaining binary
- > compatibility with older programs, which is a typical requirement.
-
- Since the publication of the trial use standard, the working group has
- agreed to drop the constant SYS_NMLN and any requirement that all
- five fields be the same length. All fields are now specified simply
- as null-terminated character arrays. Increasing the length can still
- cause binary compatibility problems, but there are (ugly) ways of
- dealing with binary compatibility.
-
- > I am also unaware of any application that makes use of the other four
- > fields.
-
- I can imagine applications using the fields in some type of reports,
- but I don't know of any portable applications which use them, or of
- any strong reason why they are needed.
-
- > Wouldn't it make more sense to standardize on a simple long character
- > string for the node name? Assuming that OSI names can somehow be
- > encoded as character strings (a fairly safe assumption, I think)
- > this ought to handle all the cases. The 4.2BSD gethostname function,
- > which passes the length of the buffer:
- > gethostname(buffer, bufferlen)
- > char *buffer;
- > int bufferlen;
- > seems perfectly suited to this problem.
-
- If we use such an approach, we still need to specify a symbolic constant
- (in <limits.h>) for the maximum length of a hostname on an
- implementation, so that applications don't need to deal with having
- truncated names returned to them. Uname handles this by the inclusion
- of the string within a structure. Given that, the only difference from
- uname is the existence of other fields. For binary compatibilty, I
- don't see much difference between an implementation having two calls
- both called "uname" or one called "uname" and the other called
- "gethostname", which return names of different lengths.
-
- Bob Lenk
- {ihnp4, hplabs}!hpfcla!rml
-
- Volume-Number: Volume 9, Number 30
-
-