The getprotoent() function is used to retrieve protocol information
from the protocol database file. When getprotoent() is first called,
the file is opened, and the first entry is returned. Each subsequent call to
getprotoent() results in the next entry in the file being returned. To
close the file, use endprotoent().
Authorities
No authorization is required.
Return Value
getprotoent() returns a pointer. Possible values are:
NULL (unsuccessful or end-of-file)
p (successful), where p is a pointer to struct
protoent.
The structure struct protoent is defined in
<netdb.h>.
struct protoent {
char *p_name;
char **p_aliases;
int p_proto;
};
p_name points to the character string that contains the name of the
protocol. p_aliases is a pointer to a NULL-terminated array of
alternate names for the protocol. p_proto is the protocol number.
System i® Navigator or the following CL commands can be
used to access the protocol database file:
WRKPCLTBLE (Work with Protocol Table Entries)
ADDPCLTBLE (Add Protocol Table Entry)
RMVPCLTBLE (Remove Protocol Table Entry)
The pointer returned by getprotoent() points to static storage
that is overwritten on subsequent calls to the getprotoent(),
getprotobynumber(), or getprotobyname() functions.
A coded character set identifier (CCSID) of 65535 for the job requests that
no database translation be performed. For translation to occur for the protocol
names returned in the protoent structure, the job CCSID must be something other
than 65535.
Do not use the getprotoent() function in a multithreaded
environment. See the multithread alternative getprotoent_r()
function.
When you develop in C-based
languages and an application is compiled with the _XOPEN_SOURCE macro defined
to the value 520 or greater, the getprotoent() API is mapped to
qso_getprotoent98().
Related Information
_XOPEN_SOURCE--Using _XOPEN_SOURCE for the UNIX® 98
compatible interface