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ghostname_unix.cpp
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1//
2// Copyright (C) 2001-2024 Graeme Walker <graeme_walker@users.sourceforge.net>
3//
4// This program is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8//
9// This program is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12// GNU General Public License for more details.
13//
14// You should have received a copy of the GNU General Public License
15// along with this program. If not, see <http://www.gnu.org/licenses/>.
16// ===
17///
18/// \file ghostname_unix.cpp
19///
20
21#include "gdef.h"
22#include "ghostname.h"
23#include "gstr.h"
24#include "genvironment.h"
25#include <sys/utsname.h>
26
27std::string G::hostname()
28{
29 struct utsname info {} ;
30 int rc = ::uname( &info ) ;
31 if( rc == -1 )
32 return {} ;
33
34 info.nodename[sizeof(info.nodename)-1U] = '\0' ;
35 std::string_view name = G::Str::headView( info.nodename , {".",1U} , false ) ;
36
37 if( name.empty() ) // pathologically "uname -n" can be empty
38 return Environment::get( "HOSTNAME" , std::string() ) ;
39
40 return Str::printable( name ) ;
41}
42
G::Str::headView
static std::string_view headView(std::string_view in, std::size_t pos, std::string_view default_={}) noexcept
Like head() but returning a view into the input string.
Definition: gstr.cpp:1308
genvironment.h
ghostname.h
gstr.h
G::hostname
std::string hostname()
Returns the hostname.
Definition: ghostname_unix.cpp:27