getprotobyname()

Get a protocol entry, given a name

Synopsis:

#include <netdb.h>

struct protoent * getprotobyname( const char * name );

Arguments:

name
The name of the protocol whose entry you want to get.

Library:

libsocket

Use the -l socket option to qcc to link against this library.

Description:

The getprotobyname() function gets the entry for the given name from the protocol database, /etc/protocols. This function returns a pointer to a structure of type protoent , which contains the broken-out fields of a line in the network protocol database.

The setprotoent() function opens and rewinds the file. If you pass a nonzero stayopen argument to setprotoent(), the protocol database isn't closed after each call to getprotobyname() or getprotobynumber() .

The getprotobyname() and getprotobynumber() functions sequentially search from the beginning of the file until a matching protocol name or protocol number is found, or until EOF is encountered.

Returns:

A pointer to a valid protoent structure, or NULL if an error occurs.

Files:

/etc/protocols
Protocol name database file.

Classification:

POSIX 1003.1

Safety:  
Cancellation point Yes
Interrupt handler No
Signal handler No
Thread No

Caveats:

This function uses static data; if you need the data for future use, copy it before any subsequent calls overwrite it.

Currently, only the Internet protocols are understood.

Last modified: 2013-12-23

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