/* * tclUnixSock.c -- * * This file contains Unix-specific socket related code. * * Copyright (c) 1995 Sun Microsystems, Inc. * * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * * RCS: @(#) $Id: tclUnixSock.c,v 1.1.1.1 2007/07/10 15:04:24 duncan Exp $ */ #include "tcl.h" #include "tclPort.h" /* * There is no portable macro for the maximum length * of host names returned by gethostbyname(). We should only * trust SYS_NMLN if it is at least 255 + 1 bytes to comply with DNS * host name limits. * * Note: SYS_NMLN is a restriction on "uname" not on gethostbyname! * * For example HP-UX 10.20 has SYS_NMLN == 9, while gethostbyname() * can return a fully qualified name from DNS of up to 255 bytes. * * Fix suggested by Viktor Dukhovni (viktor@esm.com) */ #if defined(SYS_NMLN) && SYS_NMLEN >= 256 #define TCL_HOSTNAME_LEN SYS_NMLEN #else #define TCL_HOSTNAME_LEN 256 #endif /* * The following variable holds the network name of this host. */ static char hostname[TCL_HOSTNAME_LEN + 1]; static int hostnameInited = 0; TCL_DECLARE_MUTEX(hostMutex) /* *---------------------------------------------------------------------- * * Tcl_GetHostName -- * * Returns the name of the local host. * * Results: * A string containing the network name for this machine, or * an empty string if we can't figure out the name. The caller * must not modify or free this string. * * Side effects: * None. * *---------------------------------------------------------------------- */ CONST char * Tcl_GetHostName() { #ifndef NO_UNAME struct utsname u; struct hostent *hp; #else char buffer[sizeof(hostname)]; #endif CONST char *native; Tcl_MutexLock(&hostMutex); if (hostnameInited) { Tcl_MutexUnlock(&hostMutex); return hostname; } native = NULL; #ifndef NO_UNAME (VOID *) memset((VOID *) &u, (int) 0, sizeof(struct utsname)); if (uname(&u) > -1) { /* INTL: Native. */ hp = TclpGetHostByName(u.nodename); /* INTL: Native. */ if (hp == NULL) { /* * Sometimes the nodename is fully qualified, but gets truncated * as it exceeds SYS_NMLN. See if we can just get the immediate * nodename and get a proper answer that way. */ char *dot = strchr(u.nodename, '.'); if (dot != NULL) { char *node = ckalloc((unsigned) (dot - u.nodename + 1)); memcpy(node, u.nodename, (size_t) (dot - u.nodename)); node[dot - u.nodename] = '\0'; hp = TclpGetHostByName(node); ckfree(node); } } if (hp != NULL) { native = hp->h_name; } else { native = u.nodename; } } #else /* * Uname doesn't exist; try gethostname instead. */ if (gethostname(buffer, sizeof(buffer)) > -1) { /* INTL: Native. */ native = buffer; } #endif if (native == NULL) { hostname[0] = 0; } else { Tcl_ExternalToUtf(NULL, NULL, native, -1, 0, NULL, hostname, sizeof(hostname), NULL, NULL, NULL); } hostnameInited = 1; Tcl_MutexUnlock(&hostMutex); return hostname; } /* *---------------------------------------------------------------------- * * TclpHasSockets -- * * Detect if sockets are available on this platform. * * Results: * Returns TCL_OK. * * Side effects: * None. * *---------------------------------------------------------------------- */ int TclpHasSockets(interp) Tcl_Interp *interp; /* Not used. */ { return TCL_OK; } /* *---------------------------------------------------------------------- * * TclpFinalizeSockets -- * * Performs per-thread socket subsystem finalization. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ void TclpFinalizeSockets() { return; }