what's the purpose of MAXHOSTNAMELEN?

From: Robert P. J. Day
Date: Tue Dec 29 2009 - 14:20:12 EST



in prepping for coalescing a lot of param.h files, i'm curious about
the purpose of this macro:

$ grep -rw MAXHOSTNAMELEN *
arch/s390/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/sparc/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/alpha/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/mn10300/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/arm/include/asm/param.h:#define MAXHOSTNAMELEN 64
arch/m32r/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/mips/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/m68k/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/xtensa/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/ia64/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/h8300/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/avr32/include/asm/param.h:#define MAXHOSTNAMELEN 64
arch/cris/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/um/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/powerpc/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/parisc/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
arch/frv/include/asm/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
include/asm-generic/param.h:#define MAXHOSTNAMELEN 64 /* max length of hostname */
include/net/sctp/structs.h:#include <asm/param.h> /* We get MAXHOSTNAMELEN. */
$

so lots of people define it but no one uses it. it *is* exported to
user space in /usr/include/asm/param.h, but i still have no idea what
it's for in user space. obsolete?

rday
--

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Robert P. J. Day Waterloo, Ontario, CANADA

Linux Consulting, Training and Kernel Pedantry.

Web page: http://crashcourse.ca
Twitter: http://twitter.com/rpjday
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