getprotobyname(3) Library Functions Manual getprotobyname(3)
NAME
getprotobyname, getprotobyname_r - Get a protocol entry by protocol name
LIBRARY
Standard C Library (libc.so, libc.a)
SYNOPSIS
#include <netdb.h>
struct protoent *getprotobyname( const char *name);
[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 getprotobyname_r( const char *name, struct protoent *proto, struct
protoent_data *proto_data);
STANDARDS
Interfaces documented on this reference page conform to industry standards as follows:
getprotobyname(): XNS4.0
Refer to the standards(5) reference page for more information about industry standards and associated tags.
PARAMETERS
Specifies the official protocol name or alias. [Tru64 UNIX] For getprotobyname_r(), points to the protoent structure. The netdb.h header
file defines the protoent structure. [Tru64 UNIX] For getprotobyname_r(), is data for the protocols database. The netdb.h header file
defines the protoent_data structure.
DESCRIPTION
The getprotobyname() function returns a pointer to a structure of type protoent. Its members specify data in fields from a record line in
either the local /etc/protocols file or the NIS network protocols database file. To determine which file or files to search, and in which
order, the system uses the switches in the /etc/svc.conf file. The netdb.h header file defines the protoent structure.
The getprotobyname() function searches the network protocols database file sequentially until a match with the name parameter occurs. The
name parameter will specify either the official protocol name or an alias. When EOF (End-of-File) is reached without a match, an error
value is returned by this function.
When using the getprotobyname() function, use the endprotoent() function to close the protocols file.
NOTES
The getprotobyname() 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 getprotobyname_r() function is an obsolete reentrant version of the getprotobyname() 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 getprotobyname_r() function.
RETURN VALUES
Upon successful completion, the getprotobyname() 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 getprotobyname_r() function stores the protoent structure in the location pointed to by
proto, and returns a value of 0 (zero). Upon failure, it returns a value of -1.
ERRORS
Current industry standards do not define error values for the getprotobyname() function.
[Tru64 UNIX] If any of the following conditions occurs, the getprotobyname_r() function sets errno to the corresponding value:
The proto_data or proto parameter is invalid. The search failed.
In addition, if the getprotobyname() or getprotobyname_r() function fail to open the file, it sets errno to indicate the cause of the fail-
ure.
FILES
The DARPA Internet network protocols name database file. Each record in the file occupies a single line and has three fields: the official
protocol name, the protocol number, and protocol aliases. The database service selection configuration file.
RELATED INFORMATION
Functions: getprotobynumber(3), getprotoent(3), setprotoent(3), endprotoent(3).
Files: protocols(4), svc.conf(4)
Networks: nis_intro(7)
Standards: standards(5) delim off
getprotobyname(3)