NAME

gethostname, sethostname - get/set host name

SYNOPSIS

#include <unistd.h>

int gethostname(char *name, size_t len);
int sethostname(const char *name, size_t len);

DESCRIPTION

These functions are used to access or to change the host name of the current processor. The gethostname() function returns a NUL-terminated hostname (set earlier by sethostname()) in the array name that has a length of len bytes. In case the NUL-terminated hostname does not fit, no error is returned, but the hostname is truncated. It is unspecified whether the truncated hostname will be NUL-terminated.

RETURN VALUE

On success, zero is returned. On error, -1 is returned, and errno is set appropriately.

ERRORS

EFAULT

name is an invalid address.

EINVAL

len is negative or, for sethostname(), len is larger than the maximum allowed size, or, for gethostname() on Linux/i386, len is smaller than the actual size. (In this last case glibc 2.1 uses ENAMETOOLONG.)

EPERM

For sethostname(), the caller did not have the CAP_SYS_ADMIN capability.

CONFORMING TO

SVr4, 4.4BSD (this function first appeared in 4.2BSD). POSIX 1003.1-2001 specifies gethostname() but not sethostname().

BUGS

For many Linux kernel / libc combinations gethostname() will return an error instead of returning a truncated hostname.

NOTES

SUSv2 guarantees that `Host names are limited to 255 bytes'. POSIX 1003.1-2001 guarantees that `Host names (not including the terminating NUL) are limited to HOST_NAME_MAX bytes'.

SEE ALSO

getdomainname(2), setdomainname(2), uname(2)