diff options
Diffstat (limited to 'lib/xgethostname.c')
-rw-r--r-- | lib/xgethostname.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/lib/xgethostname.c b/lib/xgethostname.c new file mode 100644 index 0000000..5b8b9b2 --- /dev/null +++ b/lib/xgethostname.c @@ -0,0 +1,84 @@ +/* xgethostname.c -- return current hostname with unlimited length + + Copyright (C) 1992, 1996, 2000, 2001, 2003, 2004, 2005 Free Software + Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +/* written by Jim Meyering */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +/* Specification. */ +#include "xgethostname.h" + +#include <stdlib.h> +#include <errno.h> + +#if HAVE_UNISTD_H +# include <unistd.h> +#endif + +#include "xalloc.h" + +#ifndef ENAMETOOLONG +# define ENAMETOOLONG 0 +#endif + +#ifndef INITIAL_HOSTNAME_LENGTH +# define INITIAL_HOSTNAME_LENGTH 34 +#endif + +/* Return the current hostname in malloc'd storage. + If malloc fails, exit. + Upon any other failure, return NULL and set errno. */ +char * +xgethostname (void) +{ + char *hostname = NULL; + size_t size = INITIAL_HOSTNAME_LENGTH; + + while (1) + { + /* Use SIZE_1 here rather than SIZE to work around the bug in + SunOS 5.5's gethostname whereby it NUL-terminates HOSTNAME + even when the name is as long as the supplied buffer. */ + size_t size_1; + + hostname = x2realloc (hostname, &size); + size_1 = size - 1; + hostname[size_1 - 1] = '\0'; + errno = 0; + + if (gethostname (hostname, size_1) == 0) + { + if (! hostname[size_1 - 1]) + break; + } + else if (errno != 0 && errno != ENAMETOOLONG && errno != EINVAL + /* OSX/Darwin does this when the buffer is not large enough */ + && errno != ENOMEM) + { + int saved_errno = errno; + free (hostname); + errno = saved_errno; + return NULL; + } + } + + return hostname; +} |