[unix-history] / usr / man / cat2 / sendto.0



SEND(2)             UNIX Programmer's Manual		  SEND(2)


N\bNA\bAM\bME\bE
     send, sendto, sendmsg - send a message from a socket

S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
     #\b#i\bin\bnc\bcl\blu\bud\bde\be <\b<s\bsy\bys\bs/\b/t\bty\byp\bpe\bes\bs.\b.h\bh>\b>
     #\b#i\bin\bnc\bcl\blu\bud\bde\be <\b<s\bsy\bys\bs/\b/s\bso\boc\bck\bke\bet\bt.\b.h\bh>\b>

     c\bcc\bc =\b= s\bse\ben\bnd\bd(\b(s\bs,\b, m\bms\bsg\bg,\b, l\ble\ben\bn,\b, f\bfl\bla\bag\bgs\bs)\b)
     i\bin\bnt\bt c\bcc\bc,\b, s\bs;\b;
     c\bch\bha\bar\br *\b*m\bms\bsg\bg;\b;
     i\bin\bnt\bt l\ble\ben\bn,\b, f\bfl\bla\bag\bgs\bs;\b;

     c\bcc\bc =\b= s\bse\ben\bnd\bdt\bto\bo(\b(s\bs,\b, m\bms\bsg\bg,\b, l\ble\ben\bn,\b, f\bfl\bla\bag\bgs\bs,\b, t\bto\bo,\b, t\bto\bol\ble\ben\bn)\b)
     i\bin\bnt\bt c\bcc\bc,\b, s\bs;\b;
     c\bch\bha\bar\br *\b*m\bms\bsg\bg;\b;
     i\bin\bnt\bt l\ble\ben\bn,\b, f\bfl\bla\bag\bgs\bs;\b;
     s\bst\btr\bru\buc\bct\bt s\bso\boc\bck\bka\bad\bdd\bdr\br *\b*t\bto\bo;\b;
     i\bin\bnt\bt t\bto\bol\ble\ben\bn;\b;

     c\bcc\bc =\b= s\bse\ben\bnd\bdm\bms\bsg\bg(\b(s\bs,\b, m\bms\bsg\bg,\b, f\bfl\bla\bag\bgs\bs)\b)
     i\bin\bnt\bt c\bcc\bc,\b, s\bs;\b;
     s\bst\btr\bru\buc\bct\bt m\bms\bsg\bgh\bhd\bdr\br *\b*m\bms\bsg\bg;\b;
     i\bin\bnt\bt f\bfl\bla\bag\bgs\bs;\b;

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
     _\bS_\be_\bn_\bd, _\bs_\be_\bn_\bd_\bt_\bo, and _\bs_\be_\bn_\bd_\bm_\bs_\bg are used to transmit a message to
     another socket.  _\bS_\be_\bn_\bd may be used only when the socket is in
     a _\bc_\bo_\bn_\bn_\be_\bc_\bt_\be_\bd state, while _\bs_\be_\bn_\bd_\bt_\bo and _\bs_\be_\bn_\bd_\bm_\bs_\bg may be used at
     any time.

     The address of the target is given by _\bt_\bo with _\bt_\bo_\bl_\be_\bn specify-
     ing its size.  The length of the message is given by _\bl_\be_\bn.
     If the message is too long to pass atomically through the
     underlying protocol, then the error EMSGSIZE is returned,
     and the message is not transmitted.

     No indication of failure to deliver is implicit in a _\bs_\be_\bn_\bd.
     Return values of -1 indicate some locally detected errors.

     If no messages space is available at the socket to hold the
     message to be transmitted, then _\bs_\be_\bn_\bd normally blocks, unless
     the socket has been placed in non-blocking I/O mode.  The
     _\bs_\be_\bl_\be_\bc_\bt(2) call may be used to determine when it is possible
     to send more data.

     The _\bf_\bl_\ba_\bg_\bs parameter may include one or more of the follow-
     ing:

	  #define  MSG_OOB	   0x1	  /* process out-of-band data */
	  #define  MSG_DONTROUTE   0x4	  /* bypass routing, use direct interface */
     The flag MSG_OOB is used to send "out-of-band" data on sock-
     ets that support this notion (e.g. SOCK_STREAM); the


Printed 7/9/88		  July 21, 1987                         1


SEND(2)             UNIX Programmer's Manual		  SEND(2)


     underlying protocol must also support "out-of-band" data.
     MSG_DONTROUTE is usually used only by diagnostic or routing
     programs.

     See _\br_\be_\bc_\bv(2) for a description of the _\bm_\bs_\bg_\bh_\bd_\br structure.

R\bRE\bET\bTU\bUR\bRN\bN V\bVA\bAL\bLU\bUE\bE
     The call returns the number of characters sent, or -1 if an
     error occurred.

E\bER\bRR\bRO\bOR\bRS\bS
     [EBADF]		 An invalid descriptor was specified.

     [ENOTSOCK]          The argument _\bs is not a socket.

     [EFAULT]		 An invalid user space address was speci-
			 fied for a parameter.

     [EMSGSIZE]          The socket requires that message be sent
			 atomically, and the size of the message
			 to be sent made this impossible.

     [EWOULDBLOCK]	 The socket is marked non-blocking and
			 the requested operation would block.

     [ENOBUFS]		 The system was unable to allocate an
			 internal buffer.  The operation may
			 succeed when buffers become available.

     [ENOBUFS]		 The output queue for a network interface
			 was full.  This generally indicates that
			 the interface has stopped sending, but
			 may be caused by transient congestion.

S\bSE\bEE\bE A\bAL\bLS\bSO\bO
     fcntl(2), recv(2), select(2), getsockopt(2), socket(2),
     write(2)


Printed 7/9/88		  July 21, 1987                         2
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2cf6fecc C	1
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	4	SEND(2) UNIX Programmer's Manual SEND(2)
	5
	6
	7
	8	N\bNA\bAM\bME\bE
	9	send, sendto, sendmsg - send a message from a socket
	10
	11	S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
	12	#\b#i\bin\bnc\bcl\blu\bud\bde\be <\b<s\bsy\bys\bs/\b/t\bty\byp\bpe\bes\bs.\b.h\bh>\b>
	13	#\b#i\bin\bnc\bcl\blu\bud\bde\be <\b<s\bsy\bys\bs/\b/s\bso\boc\bck\bke\bet\bt.\b.h\bh>\b>
	14
	15	c\bcc\bc =\b= s\bse\ben\bnd\bd(\b(s\bs,\b, m\bms\bsg\bg,\b, l\ble\ben\bn,\b, f\bfl\bla\bag\bgs\bs)\b)
	16	i\bin\bnt\bt c\bcc\bc,\b, s\bs;\b;
	17	c\bch\bha\bar\br \bm\bms\bsg\bg;\b;
	18	i\bin\bnt\bt l\ble\ben\bn,\b, f\bfl\bla\bag\bgs\bs;\b;
	19
	20	c\bcc\bc =\b= s\bse\ben\bnd\bdt\bto\bo(\b(s\bs,\b, m\bms\bsg\bg,\b, l\ble\ben\bn,\b, f\bfl\bla\bag\bgs\bs,\b, t\bto\bo,\b, t\bto\bol\ble\ben\bn)\b)
	21	i\bin\bnt\bt c\bcc\bc,\b, s\bs;\b;
	22	c\bch\bha\bar\br \bm\bms\bsg\bg;\b;
	23	i\bin\bnt\bt l\ble\ben\bn,\b, f\bfl\bla\bag\bgs\bs;\b;
	24	s\bst\btr\bru\buc\bct\bt s\bso\boc\bck\bka\bad\bdd\bdr\br \bt\bto\bo;\b;
	25	i\bin\bnt\bt t\bto\bol\ble\ben\bn;\b;
	26
	27	c\bcc\bc =\b= s\bse\ben\bnd\bdm\bms\bsg\bg(\b(s\bs,\b, m\bms\bsg\bg,\b, f\bfl\bla\bag\bgs\bs)\b)
	28	i\bin\bnt\bt c\bcc\bc,\b, s\bs;\b;
	29	s\bst\btr\bru\buc\bct\bt m\bms\bsg\bgh\bhd\bdr\br \bm\bms\bsg\bg;\b;
	30	i\bin\bnt\bt f\bfl\bla\bag\bgs\bs;\b;
	31
	32	D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
	33	_\bS_\be_\bn_\bd, _\bs_\be_\bn_\bd_\bt_\bo, and _\bs_\be_\bn_\bd_\bm_\bs_\bg are used to transmit a message to
	34	another socket. _\bS_\be_\bn_\bd may be used only when the socket is in
	35	a _\bc_\bo_\bn_\bn_\be_\bc_\bt_\be_\bd state, while _\bs_\be_\bn_\bd_\bt_\bo and _\bs_\be_\bn_\bd_\bm_\bs_\bg may be used at
	36	any time.
	37
	38	The address of the target is given by _\bt_\bo with _\bt_\bo_\bl_\be_\bn specify-
	39	ing its size. The length of the message is given by _\bl_\be_\bn.
	40	If the message is too long to pass atomically through the
	41	underlying protocol, then the error EMSGSIZE is returned,
	42	and the message is not transmitted.
	43
	44	No indication of failure to deliver is implicit in a _\bs_\be_\bn_\bd.
	45	Return values of -1 indicate some locally detected errors.
	46
	47	If no messages space is available at the socket to hold the
	48	message to be transmitted, then _\bs_\be_\bn_\bd normally blocks, unless
	49	the socket has been placed in non-blocking I/O mode. The
	50	_\bs_\be_\bl_\be_\bc_\bt(2) call may be used to determine when it is possible
	51	to send more data.
	52
	53	The _\bf_\bl_\ba_\bg_\bs parameter may include one or more of the follow-
	54	ing:
	55
	56	#define MSG_OOB 0x1 /* process out-of-band data */
	57	#define MSG_DONTROUTE 0x4 /* bypass routing, use direct interface */
	58	The flag MSG_OOB is used to send "out-of-band" data on sock-
	59	ets that support this notion (e.g. SOCK_STREAM); the
	60
	61
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	63	Printed 7/9/88 July 21, 1987 1
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70	SEND(2) UNIX Programmer's Manual SEND(2)
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74	underlying protocol must also support "out-of-band" data.
75	MSG_DONTROUTE is usually used only by diagnostic or routing
76	programs.
77
78	See _\br_\be_\bc_\bv(2) for a description of the _\bm_\bs_\bg_\bh_\bd_\br structure.
79
80	R\bRE\bET\bTU\bUR\bRN\bN V\bVA\bAL\bLU\bUE\bE
81	The call returns the number of characters sent, or -1 if an
82	error occurred.
83
84	E\bER\bRR\bRO\bOR\bRS\bS
85	[EBADF] An invalid descriptor was specified.
86
87	[ENOTSOCK] The argument _\bs is not a socket.
88
89	[EFAULT] An invalid user space address was speci-
90	fied for a parameter.
91
92	[EMSGSIZE] The socket requires that message be sent
93	atomically, and the size of the message
94	to be sent made this impossible.
95
96	[EWOULDBLOCK] The socket is marked non-blocking and
97	the requested operation would block.
98
99	[ENOBUFS] The system was unable to allocate an
100	internal buffer. The operation may
101	succeed when buffers become available.
102
103	[ENOBUFS] The output queue for a network interface
104	was full. This generally indicates that
105	the interface has stopped sending, but
106	may be caused by transient congestion.
107
108	S\bSE\bEE\bE A\bAL\bLS\bSO\bO
109	fcntl(2), recv(2), select(2), getsockopt(2), socket(2),
110	write(2)
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129	Printed 7/9/88 July 21, 1987 2
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