| .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
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| .\" References consulted: |
| .\" Linux libc source code |
| .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) |
| .\" 386BSD man pages |
| .\" Modified Sat Jul 24 19:26:03 1993 by Rik Faith (faith@cs.unc.edu) |
| .TH GETPROTOENT 3 2017-09-15 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| getprotoent, getprotobyname, getprotobynumber, setprotoent, |
| endprotoent \- get protocol entry |
| .SH SYNOPSIS |
| .nf |
| .B #include <netdb.h> |
| .PP |
| .B struct protoent *getprotoent(void); |
| .PP |
| .BI "struct protoent *getprotobyname(const char *" name ); |
| .PP |
| .BI "struct protoent *getprotobynumber(int " proto ); |
| .PP |
| .BI "void setprotoent(int " stayopen ); |
| .PP |
| .B void endprotoent(void); |
| .fi |
| .SH DESCRIPTION |
| The |
| .BR getprotoent () |
| function reads the next entry from the protocols database (see |
| .BR protocols (5)) |
| and returns a |
| .I protoent |
| structure |
| containing the broken-out fields from the entry. |
| A connection is opened to the database if necessary. |
| .PP |
| The |
| .BR getprotobyname () |
| function returns a |
| .I protoent |
| structure |
| for the entry from the database |
| that matches the protocol name |
| .IR name . |
| A connection is opened to the database if necessary. |
| .PP |
| The |
| .BR getprotobynumber () |
| function returns a |
| .I protoent |
| structure |
| for the entry from the database |
| that matches the protocol number |
| .IR number . |
| A connection is opened to the database if necessary. |
| .PP |
| The |
| .BR setprotoent () |
| function opens a connection to the database, |
| and sets the next entry to the first entry. |
| If |
| .I stayopen |
| is nonzero, |
| then the connection to the database |
| will not be closed between calls to one of the |
| .BR getproto* () |
| functions. |
| .PP |
| The |
| .BR endprotoent () |
| function closes the connection to the database. |
| .PP |
| The |
| .I protoent |
| structure is defined in |
| .I <netdb.h> |
| as follows: |
| .PP |
| .in +4n |
| .EX |
| struct protoent { |
| char *p_name; /* official protocol name */ |
| char **p_aliases; /* alias list */ |
| int p_proto; /* protocol number */ |
| } |
| .EE |
| .in |
| .PP |
| The members of the |
| .I protoent |
| structure are: |
| .TP |
| .I p_name |
| The official name of the protocol. |
| .TP |
| .I p_aliases |
| A NULL-terminated list of alternative names for the protocol. |
| .TP |
| .I p_proto |
| The protocol number. |
| .SH RETURN VALUE |
| The |
| .BR getprotoent (), |
| .BR getprotobyname () |
| and |
| .BR getprotobynumber () |
| functions return a pointer to a |
| statically allocated |
| .I protoent |
| structure, or a null pointer if an |
| error occurs or the end of the file is reached. |
| .SH FILES |
| .PD 0 |
| .TP |
| .I /etc/protocols |
| protocol database file |
| .PD |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .TS |
| allbox; |
| lbw18 lb lbw28 |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR getprotoent () |
| T} Thread safety T{ |
| MT-Unsafe race:protoent |
| .br |
| race:protoentbuf locale |
| T} |
| T{ |
| .BR getprotobyname () |
| T} Thread safety T{ |
| MT-Unsafe race:protobyname |
| .br |
| locale |
| T} |
| T{ |
| .BR getprotobynumber () |
| T} Thread safety T{ |
| MT-Unsafe race:protobynumber |
| .br |
| locale |
| T} |
| T{ |
| .BR setprotoent (), |
| .br |
| .BR endprotoent () |
| T} Thread safety T{ |
| MT-Unsafe race:protoent |
| .br |
| locale |
| T} |
| .TE |
| .sp 1 |
| In the above table, |
| .I protoent |
| in |
| .I race:protoent |
| signifies that if any of the functions |
| .BR setprotoent (), |
| .BR getprotoent (), |
| or |
| .BR endprotoent () |
| are used in parallel in different threads of a program, |
| then data races could occur. |
| .SH CONFORMING TO |
| POSIX.1-2001, POSIX.1-2008, 4.3BSD. |
| .SH SEE ALSO |
| .BR getnetent (3), |
| .BR getprotoent_r (3), |
| .BR getservent (3), |
| .BR protocols (5) |