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Linux man pages : getprotoent (3)
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

BSD 4.3

SEE ALSO

getservent(3), getnetent(3), protocols(5) BSD 1993-04-24 GETPROTOENT(3)