GETPROTOENT(3) Linux Programmer's Manual GETPROTOENT(3)NAME
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/pro‐
tocols 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:
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
The protocol number.
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
/etc/protocols
protocol database file
CONFORMING TO
4.3BSD, POSIX.1-2001.
SEE ALSOgetnetent(3), getservent(3), protocols(5)BSD 1993-04-24 GETPROTOENT(3)
