/etc/protocols
setprotoent3
Get protocol entry
Part of getprotoent(3).
Usage
#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);
Library
Standard C Library (libc, -lc)
Overview
The getprotoent(), getprotobyname(), and getprotobynumber() functions each return a pointer to an object with the following structure containing the broken-out fields of a line in the network protocol data base, /etc/protocols.
struct protoent {
char *p_name; /* official name of protocol */
char **p_aliases; /* alias list */
int p_proto; /* protocol number */
};
The members of this structure are:
- p_name
-
The official name of the protocol.
- p_aliases
-
A zero terminated list of alternate names for the protocol.
- p_proto
-
The protocol number.
The getprotoent() function reads the next line of the file, opening the file if necessary.
The setprotoent() function opens and rewinds the file. If the stayopen flag is non-zero, the net data base will not be closed after each call to getprotobyname() or getprotobynumber().
The endprotoent() function closes the file.
The getprotobyname() function and getprotobynumber() sequentially search from the beginning of the file until a matching protocol name or protocol number is found, or until EOF is encountered.
Return values
Null pointer returned on EOF or error.
Files
Releases
87 releases since FreeBSD 2.0.5-RELEASE; the text changed 43 times.