GETPROTOENT (3)
getprotoent, getprotobyname, getprotobynumber, setprotoent,
endprotoent - get protocol entry
SYNOPSIS
#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);
DESCRIPTION
The getprotoent() function reads the next line from the file
/etc/protocols and returns a structure protoent
containing the broken out fields from the line. The
/etc/protocols file is opened if necessary.
The getprotobyname() function returns a protoent
structure for the line from /etc/protocols that matches
the protocol name name.
The getprotobynumber() function returns a protoent
structure for the line that matches the protocol number number.
The setprotoent() function opens and rewinds the
/etc/protocols file. If stayopen is true (1), then
the file will not be closed between calls to getprotobyname()
or getprotobynumber().
The endprotoent() function closes /etc/protocols.
The protoent structure is defined in <netdb.h> as follows:
5
8n 16n 32n
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 zero terminated list of alternative names for the protocol.
p_proto
RETURN VALUE
The getprotoent(), getprotobyname() and getprotobynumber()
functions return the protoent structure, or a NULL pointer if an
error occurs or the end of the file is reached.
FILES
CONFORMING TO
SEE ALSO
| 
