gethostname.2 (2010 09)

gethostname(2) gethostname(2)

NAME

gethostname() - get name of current host system

SYNOPSIS

#include <unistd.h>

int gethostname(char *hostname, size_t size);

DESCRIPTION

gethostname()

returns in the array to which hostname points, the standard host name for the current

system as set by

sethostname()

(see sethostname (2)). size speciﬁes the length of the hostname array.

hostname is null-terminated unless insufﬁcient space is provided.

RETURN VALUE

gethostname()

returns 0 if successful. Otherwise, it returns −1 and sets

errno to indicate the error.

ERRORS

gethostname()

can fail if the following is true:

[EFAULT] hostname points to an illegal address. The reliable detection of this error is implementa-

tion dependent.

[EINVAL] size is less than one.

WARNINGS

It is recommended that programs use

sysconf(_SC_HOST_NAME_MAX)

to dynamically size the buffer

used to accept the host name from

gethostname()

. This is preferred over use of the MAXHOST-

NAMELEN constant.

For cases where the

MAXHOSTNAMELEN

constant must be used, there are two values: 64 and 256. The

smaller value is compatible with current releases and is used by default. To use the larger value consult

the related documentation (see nodehostnamesize(5)).

The administrator may, with appropriate conﬁguration options enabled, set a host name larger than 64

bytes. Existing applications which were compiled using the smaller

MAXHOSTNAMELEN

to size a buffer

passed to the

gethostname() system function obtain only the ﬁrst 64 bytes. This truncation may

cause the applications to exhibit anomalous behavior or to fail.

AUTHOR

gethostname() was developed by the University of California, Berkeley.

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gethostname(2) gethostname(2) NAME gethostname() - get name of current host system SYNOPSIS #include int gethostname(char *hostname, size_t size); DESCRIPTION gethostname() returns in the array to which hostname points, the standard host name for the current system as set by sethostname() (see sethostname (2)). size specifies the length of the hostname array. hostname is null-terminated unless insufficient space is provided. RETURN VALUE gethostname() returns 0 if successful.
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(Notes) A (Notes) gA 2 Hewlett-Packard Company −1− HP-UX 11i Version 3: September 2010