getprotoent, getprotobyname, getprotobynumber, setprotoent, endprotoent - get
protocol entry
#include <netdb.h>
struct protoent *getprotoent(void);
struct protoent *getprotobyname(const char *name);
struct protoent *getprotobynumber(int proto);
void setprotoent(int stayopen);
void endprotoent(void);
The
getprotoent() function reads the next entry from the protocols
database (see
protocols(5)) and returns a
protoent structure
containing the broken-out fields from the entry. A connection is opened to the
database if necessary.
The
getprotobyname() function returns a
protoent structure for the
entry from the database that matches the protocol name
name. A
connection is opened to the database if necessary.
The
getprotobynumber() function returns a
protoent structure for
the entry from the database that matches the protocol number
number. A
connection is opened to the database if necessary.
The
setprotoent() function opens a connection to the database, and sets
the next entry to the first entry. If
stayopen is nonzero, then the
connection to the database will not be closed between calls to one of the
getproto*() functions.
The
endprotoent() function closes the connection to the database.
The
protoent structure is defined in
<netdb.h> as follows:
struct protoent {
char *p_name; /* official protocol name */
char **p_aliases; /* alias list */
int p_proto; /* protocol number */
}
The members of the
protoent structure are:
- p_name
- The official name of the protocol.
- p_aliases
- A NULL-terminated list of alternative names for the protocol.
- p_proto
- The protocol number.
The
getprotoent(),
getprotobyname() and
getprotobynumber()
functions return a pointer to a statically allocated
protoent
structure, or a null pointer if an error occurs or the end of the file is
reached.
- /etc/protocols
- protocol database file
For an explanation of the terms used in this section, see
attributes(7).
Interface |
Attribute |
Value |
getprotoent () |
Thread safety |
MT-Unsafe race:protoent race:protoentbuf locale |
getprotobyname () |
Thread safety |
MT-Unsafe race:protobyname locale |
getprotobynumber () |
Thread safety |
MT-Unsafe race:protobynumber locale |
setprotoent (), endprotoent () |
Thread safety |
MT-Unsafe race:protoent locale |
In the above table,
protoent in
race:protoent signifies that if
any of the functions
setprotoent(),
getprotoent(), or
endprotoent() are used in parallel in different threads of a program,
then data races could occur.
POSIX.1-2001, POSIX.1-2008, 4.3BSD.
getnetent(3),
getprotoent_r(3),
getservent(3),
protocols(5)