getprotoent(3) Library Functions Manual getprotoent(3)
NAME
getprotoent, getprotoent_r - Get a protocol entry
LIBRARY
Standard C Library (libc.so, libc.a)
SYNOPSIS
#include <netdb.h>
struct protoent *getprotoent(void);
[Tru64 UNIX] The following obsolete function is supported in order to maintain backward compatibility with previous versions of the oper-
ating system. You should not use it in new designs. int getprotoent_r( struct protoent *proto, struct protoent_data
*proto_data);
STANDARDS
Interfaces documented on this reference page conform to industry standards as follows:
getprotoent(): XNS4.0
Refer to the standards(5) reference page for more information about industry standards and associated tags.
PARAMETERS
[Tru64 UNIX] For getprotoent_r(), points to the protoent structure. The netdb.h header file defines the protoent structure. [Tru64
UNIX] For getprotoent_r(), is data for the protocols database. The netdb.h header file defines the protoent_data structure.
DESCRIPTION
The getprotoent() (get protocol entry) function retrieves protocol information from either the local /etc/protocols file or the NIS dis-
tributed networks file for the requested information. To determine which file or files to search, and in which order, the system uses the
switches in the /etc/svc.conf file.
The getprotoent() function returns a pointer to a protoent structure, which contains the fields for a line of information in the networks
protocols database file. The netdb.h header file defines the protoent structure.
An application program can use the getprotoent() function to access a protocol name, its aliases, and protocol number. Use the endpro-
toent() function to close the /etc/protocols file. Use the setprotoent() function to rewind.
NOTES
The getprotoent() function returns a pointer to thread-specific data. Subsequent calls to this or a related function from the same thread
overwrite this data.
[Tru64 UNIX] The getprotoent_r() function is an obsolete reentrant version of the getprotoent() function. It is supported in order to
maintain backward compatibility with previous versions of the operating system and should not be used in new designs. Note that you must
zero-fill the proto_data structure before its first access by either the setprotoent_r() or getprotoent_r() function. When using the get-
protoent_r() function, use the setprotoent_r() function to rewind the network protocols database file and the endprotoent_r() function to
close it.
RETURN VALUES
Upon successful completion, the getprotoent() function returns a pointer to a protoent structure. If it fails or reaches the end of the
network protocols database file, it returns a null pointer.
[Tru64 UNIX] Upon successful completion, the getprotoent_r() function stores the protoent structure in the location pointed to by proto,
and returns a value of 0 (zero). Otherwise it returns a value of -1.
ERRORS
Current industry standards do not define error values for the getprotoent() function.
[Tru64 UNIX] If any of the following conditions occurs, the getprotoent_r() function sets errno to the corresponding value: The proto or
proto_data parameter is invalid. The search failed.
In addition, if the getprotoent() or getprotoent_r() function fails to open the file, it sets errno to indicate the cause of the failure.
FILES
Contains protocol information. The database service selection configuration file.
RELATED INFORMATION
Functions: getprotobynumber(3), getprotobyname(3), setprotoent(3), endprotoent(3).
Files: protocols(4), svc.conf(4).
Networks: nis_intro(7).
Standards: standards(5). delim off
getprotoent(3)