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71 lines
1.8 KiB
C
71 lines
1.8 KiB
C
/* A slightly more convenient wrapper for gethostname
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Copyright (C) 1996 Free Software Foundation, Inc.
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Written by Miles Bader <miles@gnu.ai.mit.edu>
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2, or (at
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your option) any later version.
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This program is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#include <unistd.h>
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#include <malloc.h>
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#include <string.h>
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#include <errno.h>
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/* Return the name of the localhost. This is just a wrapper for gethostname,
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which takes care of allocating a big enough buffer, and caches the result
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after the first call (so the result should be copied before modification).
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If something goes wrong, 0 is returned, and errno set. */
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char *
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localhost ()
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{
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static char *buf = 0;
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static size_t buf_len = 0;
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if (! buf)
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{
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do {
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errno = 0;
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if (buf) {
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buf_len += buf_len;
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buf = realloc (buf, buf_len);
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} else {
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buf_len = 128; /* Initial guess */
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buf = malloc (buf_len);
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}
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if (! buf)
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{
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errno = ENOMEM;
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return 0;
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}
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} while ((gethostname(buf, buf_len) == 0 && !memchr (buf, '\0', buf_len))
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|| errno == ENAMETOOLONG);
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if (errno)
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/* gethostname failed, abort. */
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{
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free (buf);
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buf = 0;
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}
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}
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return buf;
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}
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