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85 lines
2.1 KiB
C
85 lines
2.1 KiB
C
/* xgethostname.c -- return current hostname with unlimited length
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Copyright (C) 1992, 1996, 2000, 2001, 2003, 2004, 2005 Free Software
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Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU 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 Foundation,
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Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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/* written by Jim Meyering */
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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/* Specification. */
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#include "xgethostname.h"
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#include <stdlib.h>
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#include <errno.h>
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#if HAVE_UNISTD_H
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# include <unistd.h>
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#endif
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#include "xalloc.h"
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#ifndef ENAMETOOLONG
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# define ENAMETOOLONG 0
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#endif
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#ifndef INITIAL_HOSTNAME_LENGTH
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# define INITIAL_HOSTNAME_LENGTH 34
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#endif
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/* Return the current hostname in malloc'd storage.
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If malloc fails, exit.
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Upon any other failure, return NULL and set errno. */
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char *
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xgethostname (void)
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{
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char *hostname = NULL;
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size_t size = INITIAL_HOSTNAME_LENGTH;
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while (1)
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{
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/* Use SIZE_1 here rather than SIZE to work around the bug in
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SunOS 5.5's gethostname whereby it NUL-terminates HOSTNAME
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even when the name is as long as the supplied buffer. */
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size_t size_1;
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hostname = x2realloc (hostname, &size);
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size_1 = size - 1;
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hostname[size_1 - 1] = '\0';
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errno = 0;
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if (gethostname (hostname, size_1) == 0)
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{
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if (! hostname[size_1 - 1])
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break;
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}
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else if (errno != 0 && errno != ENAMETOOLONG && errno != EINVAL
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/* OSX/Darwin does this when the buffer is not large enough */
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&& errno != ENOMEM)
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{
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int saved_errno = errno;
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free (hostname);
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errno = saved_errno;
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return NULL;
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}
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}
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return hostname;
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}
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