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Diffstat (limited to 'contrib/perl5/lib/Sys/Hostname.pm')
| -rw-r--r-- | contrib/perl5/lib/Sys/Hostname.pm | 121 | 
1 files changed, 121 insertions, 0 deletions
| diff --git a/contrib/perl5/lib/Sys/Hostname.pm b/contrib/perl5/lib/Sys/Hostname.pm new file mode 100644 index 0000000000000..95f9a99a7abf2 --- /dev/null +++ b/contrib/perl5/lib/Sys/Hostname.pm @@ -0,0 +1,121 @@ +package Sys::Hostname; + +use Carp; +require Exporter; +@ISA = qw(Exporter); +@EXPORT = qw(hostname); + +=head1 NAME + +Sys::Hostname - Try every conceivable way to get hostname + +=head1 SYNOPSIS + +    use Sys::Hostname; +    $host = hostname; + +=head1 DESCRIPTION + +Attempts several methods of getting the system hostname and +then caches the result.  It tries C<syscall(SYS_gethostname)>, +C<`hostname`>, C<`uname -n`>, and the file F</com/host>. +If all that fails it C<croak>s. + +All nulls, returns, and newlines are removed from the result. + +=head1 AUTHOR + +David Sundstrom E<lt>F<sunds@asictest.sc.ti.com>E<gt> + +Texas Instruments + +=cut + +sub hostname { + +  # method 1 - we already know it +  return $host if defined $host; + +  if ($^O eq 'VMS') { + +    # method 2 - no sockets ==> return DECnet node name +    eval { local $SIG{__DIE__}; $host = (gethostbyname('me'))[0] }; +    if ($@) { return $host = $ENV{'SYS$NODE'}; } + +    # method 3 - has someone else done the job already?  It's common for the +    #    TCP/IP stack to advertise the hostname via a logical name.  (Are +    #    there any other logicals which TCP/IP stacks use for the host name?) +    $host = $ENV{'ARPANET_HOST_NAME'}  || $ENV{'INTERNET_HOST_NAME'} || +            $ENV{'MULTINET_HOST_NAME'} || $ENV{'UCX$INET_HOST'}      || +            $ENV{'TCPWARE_DOMAINNAME'} || $ENV{'NEWS_ADDRESS'}; +    return $host if $host; + +    # method 4 - does hostname happen to work? +    my($rslt) = `hostname`; +    if ($rslt !~ /IVVERB/) { ($host) = $rslt =~ /^(\S+)/; } +    return $host if $host; + +    # rats! +    $host = ''; +    Carp::croak "Cannot get host name of local machine";   + +  } +  elsif ($^O eq 'MSWin32') { +    ($host) = gethostbyname('localhost'); +    chomp($host = `hostname 2> NUL`) unless defined $host; +    return $host; +  } +  else {  # Unix + +    # method 2 - syscall is preferred since it avoids tainting problems +    eval { +	local $SIG{__DIE__}; +	{ +	    package main; +	    require "syscall.ph"; +	} +	$host = "\0" x 65; ## preload scalar +	syscall(&main::SYS_gethostname, $host, 65) == 0; +    } + +    # method 2a - syscall using systeminfo instead of gethostname +    #           -- needed on systems like Solaris +    || eval { +	local $SIG{__DIE__}; +	{ +	    package main; +	    require "sys/syscall.ph"; +	    require "sys/systeminfo.ph"; +	} +	$host = "\0" x 65; ## preload scalar +	syscall(&main::SYS_systeminfo, &main::SI_HOSTNAME, $host, 65) != -1; +    } + +    # method 3 - trusty old hostname command +    || eval { +	local $SIG{__DIE__}; +	$host = `(hostname) 2>/dev/null`; # bsdish +    } + +    # method 4 - sysV uname command (may truncate) +    || eval { +	local $SIG{__DIE__}; +	$host = `uname -n 2>/dev/null`; ## sysVish +    } + +    # method 5 - Apollo pre-SR10 +    || eval { +	local $SIG{__DIE__}; +	($host,$a,$b,$c,$d)=split(/[:\. ]/,`/com/host`,6); +    } + +    # bummer +    || Carp::croak "Cannot get host name of local machine";   + +    # remove garbage  +    $host =~ tr/\0\r\n//d; +    $host; +  } +} + +1; | 
