|
|
Synopsis Environment
Description Diagnostics
Notes See also
Examples |
Synopsis |
#include "ucm.h" int UcmServer(service,
DoService);
char *service;
int (*DoService)(T_SOCKET sock); |
Environment |
Unix, Win32
|
Description |
The UcmServer function provides the same services as
the UcmServer(U) utility. In contrast to the utility
implementation, UcmServer allows you to develop self-contained servers. This server
type features faster connect times, since it does not have to use the exec(2)
system call. It results however in larger executables for the daemon, since it includes
the full server logic. The call of this function will detach the program from the parent
process, unless the parent has the PID 1, i.e. is the init(1) process. The first
argument identifies the service that the socket will be assigned to. Service
may be given as symbolic TCP/IP service name or as numeric port number. When using
the symbolic service name, it must be defined in /etc/services or the
Windows services file with type ftp.
After each successful connect request, UcmServer forks (fork(2)) and
calls the function at address DoService with the socket number sock as first
and only argument. On Win32 platforms each DoService invocation
is executed in its own thread. The DoService function should use UcmOpen for the new socket and return a non negative (int)
return code after UcmClose.
UcmServer will fail if one or more of the following is true:
| UE_NOTINIT |
The UCM software has not been initialize (see UcmInit) |
| UE_INVALID |
An invalid parameter has been passed. |
| UE_SERVICE |
The value service does not identify a known service (i.e. is not
defined in /etc/services). |
| UE_CONNECT |
The bind(2) or accept(2) system call has
failed. |
| UE_INTR |
The accept(2) system call has been interrupted by a signal. |
|
Diagnostics |
Upon successful completion UcmServer returns (int)
>= 0. Otherwise, a value of UCM_ERROR is returned and ucmErrno is set to
indicate the error.
|
Notes |
Typically programs using the UcmServer function, are
invoked at boot time from the /etc/rc startup file or from /etc/inittab
(System V only).
|
See also |
init(1), initab(4), services(4), UcmOpen,
UcmServer(U), UcmTerm
|
Examples |
| #include
"ucm.h" #if defined(__STDC__)
static int DoService(T_SOCKET sock);
#else
static int DoService();
#endif
main()
{
ucmProgName = argv[0]; /* for UCM error messages */
UcmInit();
UcmServer("7001", DoService);
UcmTerm();
return 0;
}
static int DoService(sock)
T_SOCKET sock;
{
T_UCM_MSG msg; /* buffer to hold message */
T_UCM_MSGID msgId; /* buffer to hold message ID */
if (UcmOpen(sock))
Error("UcmOpen failed");
while (UcmRecv(sock, msgId, msg, -1, UF_NOFLAGS) > 0)
{
/* this server just echoes back its input */
UcmSendf(sock, "Got
‘%s:%s’", msgId, msg);
}
UcmClose(sock);
return 0;
} |
|
|
|
