diff options
Diffstat (limited to 'libshouldbeinlibc/localhost.c')
-rw-r--r-- | libshouldbeinlibc/localhost.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/libshouldbeinlibc/localhost.c b/libshouldbeinlibc/localhost.c new file mode 100644 index 00000000..f0c67541 --- /dev/null +++ b/libshouldbeinlibc/localhost.c @@ -0,0 +1,66 @@ +/* A slightly more convenient wrapper for gethostname + + Copyright (C) 1996 Free Software Foundation, Inc. + + Written by Miles Bader <miles@gnu.ai.mit.edu> + + 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include <unistd.h> +#include <malloc.h> +#include <string.h> +#include <errno.h> + +/* Return the name of the localhost. This is just a wrapper for gethostname, + which takes care of allocating a big enough buffer, and caches the result + after the first call (so the result should be copied before modification). + If something goes wrong, 0 is returned, and errno set. */ +char * +localhost () +{ + static char *buf = 0; + static size_t buf_len = 0; + + if (! buf) + { + do { + errno = 0; + + if (buf) { + buf_len += buf_len; + buf = realloc (buf, buf_len); + } else { + buf_len = 128; /* Initial guess */ + buf = malloc (buf_len); + } + + if (! buf) + { + errno = ENOMEM; + return 0; + } + } while ((gethostname(buf, buf_len) == 0 && !memchr (buf, '\0', buf_len)) + || errno == ENAMETOOLONG); + + if (errno) + /* gethostname failed, abort. */ + { + free (buf); + buf = 0; + } + } + + return buf; +} |