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IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)getprotoent.3 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD: src/lib/libc/net/getprotoent.3,v 1.12 2007/01/09 00:28:02 imp Exp $ 30.\" 31.Dd May 4, 2019 32.Dt GETPROTOENT 3 33.Os 34.Sh NAME 35.Nm getprotoent , 36.Nm getprotoent_r , 37.Nm getprotobynumber , 38.Nm getprotobynumber_r , 39.Nm getprotobyname , 40.Nm getprotobyname_r , 41.Nm setprotoent , 42.Nm endprotoent 43.Nd get protocol entry 44.Sh LIBRARY 45.Lb libc 46.Sh SYNOPSIS 47.In netdb.h 48.Ft struct protoent * 49.Fn getprotoent void 50.Ft int 51.Fn getprotoent_r "struct protoent *" "char *" "size_t" "struct protoent **" 52.Ft struct protoent * 53.Fn getprotobyname "const char *name" 54.Ft int 55.Fn getprotobyname_r "const char *" "struct protoent *" "char *" "size_t" "struct protoent **" 56.Ft struct protoent * 57.Fn getprotobynumber "int proto" 58.Ft int 59.Fn getprotobynumber_r "int" "struct protoent *" "char *" "size_t" "struct protoent **" 60.Ft void 61.Fn setprotoent "int stayopen" 62.Ft void 63.Fn endprotoent void 64.Sh DESCRIPTION 65The 66.Fn getprotoent , 67.Fn getprotobyname , 68and 69.Fn getprotobynumber 70functions 71each return a pointer to an object with the 72following structure 73containing the broken-out 74fields of a line in the network protocol data base, 75.Pa /etc/protocols . 76.Bd -literal -offset indent 77struct protoent { 78 char *p_name; /* official name of protocol */ 79 char **p_aliases; /* alias list */ 80 int p_proto; /* protocol number */ 81}; 82.Ed 83.Pp 84The members of this structure are: 85.Bl -tag -width p_aliases 86.It Fa p_name 87The official name of the protocol. 88.It Fa p_aliases 89A zero terminated list of alternate names for the protocol. 90.It Fa p_proto 91The protocol number. 92.El 93.Pp 94The 95.Fn getprotoent 96function 97reads the next line of the file, opening the file if necessary. 98.Pp 99The 100.Fn setprotoent 101function 102opens and rewinds the file. 103If the 104.Fa stayopen 105flag is non-zero, 106the net data base will not be closed after each call to 107.Fn getprotobyname 108or 109.Fn getprotobynumber . 110.Pp 111The 112.Fn endprotoent 113function 114closes the file. 115.Pp 116The 117.Fn getprotobyname 118function 119and 120.Fn getprotobynumber 121sequentially search from the beginning 122of the file until a matching 123protocol name or 124protocol number is found, 125or until 126.Dv EOF 127is encountered. 128.Pp 129The 130.Fn getprotoent_r , 131.Fn getprotobynumber_r , 132and 133.Fn getprotobyname_r 134functions are reentrant versions of the above functions that take a 135pointer to a 136.Vt protoent 137structure which is used to store state information. 138The structure must be zero-filled before it is used 139and should be considered opaque for the sake of portability. 140These functions also take a pointer to another 141.Vt protoent 142structure which is used to store the results of the database lookup. 143.Sh RETURN VALUES 144The 145.Fn getprotoent , 146.Fn getprotobynumber , 147and 148.Fn getprotobyname 149functions return a pointer to a 150.Vt protoent 151structure on success or a null pointer if end-of-file 152is reached or an error occurs. 153.Pp 154The 155.Fn getprotoent_r , 156.Fn getprotobynumber_r , 157and 158.Fn getprotobyname_r 159functions return 0 on success or \-1 if end-of-file 160is reached or an error occurs. 161.Sh FILES 162.Bl -tag -width ".Pa /etc/protocols" -compact 163.It Pa /etc/protocols 164.El 165.Sh SEE ALSO 166.Xr protocols 5 167.Sh STANDARDS 168The 169.Fn getprotoent , 170.Fn getprotobynumber , 171.Fn getprotobyname , 172.Fn setprotoent , 173and 174.Fn endprotoent 175functions conform to 176.St -p1003.1-2004 . 177.Pp 178The 179.Fn getprotoent_r , 180.Fn getprotobynumber_r , 181and 182.Fn getprotobyname_r 183functions are not currently standardized. 184.Sh HISTORY 185The 186.Fn getprotoent , 187.Fn getprotobynumber , 188.Fn getprotobyname , 189.Fn setprotoent , 190and 191.Fn endprotoent 192functions appeared in 193.Bx 4.2 . 194.Pp 195The 196.Fn getprotoent_r , 197.Fn getprotobynumber_r , 198and 199.Fn getprotobyname_r 200functions appeared in 201.Dx 2.1 . 202.Sh BUGS 203These functions use a thread-specific data space; 204if the data is needed for future use, it should be 205copied before any subsequent calls overwrite it. 206Only the Internet 207protocols are currently understood. 208