GETPROTOENT
NAME SYNOPSIS DESCRIPTION RETURN VALUE FILES CONFORMING TO SEE ALSO
getprotoent, getprotobyname, getprotobynumber, setprotoent, endprotoent - get protocol entry
#include name); struct protoent *getprotobynumber(int proto); void setprotoent(int stayopen); void endprotoent(void);
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 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.
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.
/etc/protocols
protocol database file
BSD 4.3
getservent(3), getnetent(3), protocols(5)
One page links to getprotobynumber(3):