把链表S中从第m个元素起共n个元素存储到s中,成功返回1,否则返回0int len(STRING S)
上传时间: 2013-12-10
上传用户:siguazgb
其中的usb端口通信已经作为一个模块来使用,用户只需用以下函数就可以对usb端口进行方便地读写: unsigned char D12_WriteEndpoint(unsigned char endp, unsigned char len, unsigned char * buf) 此为usb端点输出函数,endp是要进行通信的端点,取值为3(普通端点,最大可一次传输16byte)或5(主端点,最大可一次传输64byte);len为一次输出数据长度;*buf为数据所在位置。 usb端点数据的读操作是由底层函数自动完成的(相关函数为unsigned char D12_ReadEndpoint(unsigned char endp, unsigned char len, unsigned char * buf); 相应端点为2和4),所读到的数据存于GenEpBuf[](普通端点)、MainEpBuf[]或EpBuf[](主端点)中,用户可以直接读取使用。
上传时间: 2013-11-30
上传用户:jennyzai
client socket include <sys/types.h> include <sys/socket.h> include <stdio.h> include <netinet/in.h> include <arpa/inet.h> include <unistd.h> int main() { int sockfd int len struct sockaddr_in address int result char ch = A sockfd = socket(AF_INET, SOCK_STREAM, 0) address.sin_family = AF_INET address.sin_addr.s_addr = inet_addr("127.0.0.1") address.sin_port = 9734 len = sizeof(address) result = connect(sockfd, (struct sockaddr *)&address, len) if(result == -1) { perror("oops: client") exit(1) } write(sockfd, &ch, 1) read(sockfd, &ch, 1) printf("char from server = c\n", ch) close(sockfd) exit(0) }
上传时间: 2017-07-29
上传用户:wab1981
1.采用指定算法模拟动态分区管理方式的主存分配。能够处理以下的情形: ⑴ 随机出现的进程i申请jKB内存,程序能判断是否能分配,如果能分配,要求输出分配的首地址Faddress,并要求输出内存使用情况和空闲情况。 内存情况输出的格式为:Faddress该分区的首地址;Eaddress该分区的尾地址 len 分区长度;Process 如果使用,使用的进程号,否则为0 ⑵ 主存分配函数实现寻找空闲区、空闲区表的修改、已分配区表的修改功能。
上传时间: 2013-12-29
上传用户:zhuyibin
/* ********************************************************************************************************* * uC/TCP-IP V2 * The Embedded TCP/IP Suite * * (c) Copyright 2003-2010; Micrium, Inc.; Weston, FL * * All rights reserved. Protected by international copyright laws. * * uC/TCP-IP is provided in source form to registered licensees ONLY. It is * illegal to distribute this source code to any third party unless you receive * written permission by an authorized Micrium representative. Knowledge of * the source code may NOT be used to develop a similar product. * * Please help us continue to provide the Embedded community with the finest * software available. Your honesty is greatly appreciated. * * You can contact us at www.micrium.com. ********************************************************************************************************* */ /* ********************************************************************************************************* * * NETWORK TCP LAYER * (TRANSMISSION CONTROL PROTOCOL) * * Filename : net_tcp.h * Version : V2.10 * Programmer(s) : ITJ ********************************************************************************************************* * Note(s) : (1) Supports Transmission Control Protocol as described in RFC #793 with the following * restrictions/constraints : * * (a) TCP Security & Precedence NOT supported RFC # 793, Section 3.6 * * (b) TCP Urgent Data NOT supported RFC # 793, Section 3.7 * 'The Communication of * Urgent Information' * * (c) The following TCP options NOT supported : * * (1) Window Scale RFC #1072, Section 2 * RFC #1323, Section 2 * (2) Selective Acknowledgement (SACK) RFC #1072, Section 3 * RFC #2018 * RFC #2883 * (3) TCP Echo RFC #1072, Section 4 * (4) Timestamp RFC #1323, Section 3.2 * (5) Protection Against Wrapped Sequences (PAWS) RFC #1323, Section 4 * * (d) #### IP-Options-to-TCP-Connection RFC #1122, Section 4.2.3.8 * Handling NOT supported * * (e) #### ICMP-Error-Message-to-TCP-Connection RFC #1122, Section 4.2.3.9 * Handling NOT currently supported * * (2) TCP Layer assumes/requires Network Socket Layer (see 'net_sock.h MODULE Note #1a2'). ********************************************************************************************************* */ /*$PAGE*/ /* ********************************************************************************************************* * MODULE * * Note(s) : (1) TCP Layer module is NOT required for UDP-to-Application API configuration. * * See also 'net_cfg.h TRANSPORT LAYER CONFIGURATION' * & 'net_cfg.h USER DATAGRAM PROTOCOL LAYER CONFIGURATION'. * * See also 'net_tcp.h Note #2'. * * (2) The following TCP-module-present configuration value MUST be pre-#define'd in * 'net_cfg_net.h' PRIOR to all other network modules that require TCP Layer * configuration (see 'net_cfg_net.h TCP LAYER CONFIGURATION Note #2b') : * * NET_TCP_MODULE_PRESENT ********************************************************************************************************* */ #ifdef NET_TCP_MODULE_PRESENT /* See Note #2. */ /* ********************************************************************************************************* * EXTERNS ********************************************************************************************************* */ #if ((defined(NET_TCP_MODULE)) && \ (defined(NET_GLOBALS_EXT))) #define NET_TCP_EXT #else #define NET_TCP_EXT extern #endif /*$PAGE*/ /* ********************************************************************************************************* * DEFINES ********************************************************************************************************* */ /* ********************************************************************************************************* * TCP HEADER DEFINES * * Note(s) : (1) The following TCP value MUST be pre-#define'd in 'net_def.h' PRIOR to 'net_buf.h' so that * the Network Buffer Module can configure maximum buffer header size (see 'net_def.h TCP * LAYER DEFINES' & 'net_buf.h NETWORK BUFFER INDEX & SIZE DEFINES Note #1') : * * (a) NET_TCP_HDR_SIZE_MAX 60 (NET_TCP_HDR_len_MAX * * NET_TCP_HDR_len_WORD_SIZE) * * (2) Urgent pointer & data NOT supported (see 'net_tcp.h Note #1b'). ********************************************************************************************************* */ #define NET_TCP_HDR_len_MASK 0xF000u #define NET_TCP_HDR_len_SHIFT 12u #define NET_TCP_HDR_len_NONE 0u #define NET_TCP_HDR_len_MIN 5u #define NET_TCP_HDR_len_MAX 15u #define NET_TCP_HDR_len_WORD_SIZE CPU_WORD_SIZE_32 #define NET_TCP_HDR_SIZE_MIN (NET_TCP_HDR_len_MIN * NET_TCP_HDR_len_WORD_SIZE) #if 0 /* See Note #1a. */ #define NET_TCP_HDR_SIZE_MAX (NET_TCP_HDR_len_MAX * NET_TCP_HDR_len_WORD_SIZE) #endif #define NET_TCP_HDR_SIZE_TOT_MIN (NET_IP_HDR_SIZE_TOT_MIN + NET_TCP_HDR_SIZE_MIN) #define NET_TCP_HDR_SIZE_TOT_MAX (NET_IP_HDR_SIZE_TOT_MAX + NET_TCP_HDR_SIZE_MAX) #define NET_TCP_PSEUDO_HDR_SIZE 12u /* = sizeof(NET_TCP_PSEUDO_HDR) */ #define NET_TCP_PORT_NBR_RESERVED NET_PORT_NBR_RESERVED #define NET_TCP_PORT_NBR_NONE NET_TCP_PORT_NBR_RESERVED #define NET_TCP_HDR_URG_PTR_NONE 0x0000u /* See Note #2. */ /*$PAGE*/ /* ********************************************************************************************************* * TCP HEADER FLAG DEFINES * * Note(s) : (1) See 'TCP HEADER Note #2' for flag fields. * * (2) Urgent pointer & data NOT supported (see 'net_tcp.h Note #1b'). ********************************************************************************************************* */ #define NET_TCP_HDR_FLAG_MASK 0x0FFFu #define NET_TCP_HDR_FLAG_NONE DEF_BIT_NONE #define NET_TCP_HDR_FLAG_RESERVED 0x0FE0u /* MUST be '0'. */ #define NET_TCP_HDR_FLAG_URGENT DEF_BIT_05 /* See Note #2. */ #define NET_TCP_HDR_FLAG_ACK DEF_BIT_04 #define NET_TCP_HDR_FLAG_PUSH DEF_BIT_03 #define NET_TCP_HDR_FLAG_RESET DEF_BIT_02 #define NET_TCP_HDR_FLAG_SYNC DEF_BIT_01 #define NET_TCP_HDR_FLAG_FIN DEF_BIT_00 #define NET_TCP_HDR_FLAG_CLOSE NET_TCP_HDR_FLAG_FIN /* ********************************************************************************************************* * TCP FLAG DEFINES ********************************************************************************************************* */ /* ------------------ NET TCP FLAGS ------------------- */ #define NET_TCP_FLAG_NONE DEF_BIT_NONE #define NET_TCP_FLAG_USED DEF_BIT_00 /* TCP conn cur used; i.e. NOT in free TCP conn pool. */ /* ------------------ TCP TX FLAGS ------------------- */ /* TCP tx flags copied from TCP hdr flags. */ #define NET_TCP_FLAG_TX_FIN NET_TCP_HDR_FLAG_FIN #define NET_TCP_FLAG_TX_CLOSE NET_TCP_FLAG_TX_FIN #define NET_TCP_FLAG_TX_SYNC NET_TCP_HDR_FLAG_SYNC #define NET_TCP_FLAG_TX_RESET NET_TCP_HDR_FLAG_RESET #define NET_TCP_FLAG_TX_PUSH NET_TCP_HDR_FLAG_PUSH #define NET_TCP_FLAG_TX_ACK NET_TCP_HDR_FLAG_ACK #define NET_TCP_FLAG_TX_URGENT NET_TCP_HDR_FLAG_URGENT #define NET_TCP_FLAG_TX_BLOCK DEF_BIT_07 /* ------------------ TCP RX FLAGS ------------------- */ #define NET_TCP_FLAG_RX_DATA_PEEK DEF_BIT_08 #define NET_TCP_FLAG_RX_BLOCK DEF_BIT_15 /*$PAGE*/ /* ********************************************************************************************************* * TCP TYPE DEFINES * * Note(s) : (1) NET_TCP_TYPE_&&& #define values specifically chosen as ASCII representations of the TCP * types. Memory displays of TCP types will display with their chosen ASCII names. ********************************************************************************************************* */ /* ------------------ NET TCP TYPES ------------------- */ #if (CPU_CFG_ENDIAN_TYPE == CPU_ENDIAN_TYPE_BIG) #define NET_TCP_TYPE_NONE 0x4E4F4E45u /* "NONE" in ASCII. */ #define NET_TCP_TYPE_CONN 0x54435020u /* "TCP " in ASCII. */ #else #if (CPU_CFG_DATA_SIZE == CPU_WORD_SIZE_32) #define NET_TCP_TYPE_NONE 0x454E4F4Eu /* "NONE" in ASCII. */ #define NET_TCP_TYPE_CONN 0x20504354u /* "TCP " in ASCII. */ #elif (CPU_CFG_DATA_SIZE == CPU_WORD_SIZE_16) #define NET_TCP_TYPE_NONE 0x4F4E454Eu /* "NONE" in ASCII. */ #define NET_TCP_TYPE_CONN 0x43542050u /* "TCP " in ASCII. */ #else /* Dflt CPU_WORD_SIZE_08. */ #define NET_TCP_TYPE_NONE 0x4E4F4E45u /* "NONE" in ASCII. */ #define NET_TCP_TYPE_CONN 0x54435020u /* "TCP " in ASCII. */ #endif #endif /* ********************************************************************************************************* * TCP SEQUENCE NUMBER DEFINES * * Note(s) : (1) TCP initial transmit sequence number is incremented by a fixed value, preferably a large * prime value or a large value with multiple unique factors. * * (a) One reasonable TCP initial transmit sequence number increment value example : * * 65527 = 37 * 23 * 11 * 7 * * * #### NET_TCP_TX_SEQ_NBR_CTR_INC could be developer-configured in 'net_cfg.h'. * * See also 'NET_TCP_TX_GET_SEQ_NBR() Notes #1b2 & #1c2'. ********************************************************************************************************* */ #define NET_TCP_SEQ_NBR_NONE 0u #define NET_TCP_ACK_NBR_NONE NET_TCP_SEQ_NBR_NONE #define NET_TCP_TX_SEQ_NBR_CTR_INC 65527u /* See Note #1. */ #define NET_TCP_ACK_NBR_DUP_WIN_SIZE_SCALE 4 /*$PAGE*/ /* ********************************************************************************************************* * TCP DATA/TOTAL lenGTH DEFINES * * Note(s) : (1) (a) TCP total length #define's (NET_TCP_TOT_len) relate to the total size of a complete * TCP packet, including the packet's TCP header. Note that a complete TCP packet MAY * be fragmented in multiple Internet Protocol packets. * * (b) TCP data length #define's (NET_TCP_DATA_len) relate to the data size of a complete * TCP packet, equal to the total TCP packet length minus its TCP header size. Note * that a complete TCP packet MAY be fragmented in multiple Internet Protocol packets. ********************************************************************************************************* */ /* See Notes #1a & #1b. */ #define NET_TCP_DATA_len_MIN 0u #define NET_TCP_TOT_len_MIN (NET_TCP_HDR_SIZE_MIN + NET_TCP_DATA_len_MIN) #define NET_TCP_TOT_len_MAX (NET_IP_TOT_len_MAX - NET_IP_HDR_SIZE_MIN ) #define NET_TCP_DATA_len_MAX (NET_TCP_TOT_len_MAX - NET_TCP_HDR_SIZE_MIN) /*$PAGE*/ /* ********************************************************************************************************* * TCP SEGMENT SIZE DEFINES * * Note(s) : (1) (a) RFC # 879, Section 3 states that the TCP Maximum Segment Size "counts only * data octets in the segment, ... not the TCP header or the IP header". * * (b) RFC #1122, Section 4.2.2.6 requires that : * * (1) "The MSS value to be sent in an MSS option must be less than or equal to * * (A) MMS_R - 20 * * where MMS_R is the maximum size for a transport-layer message that can * be received." * * (2) "If an MSS option is not received at connection setup, TCP MUST assume a * default send MSS of 536 (576 - 40)." * * See also 'net_ip.h IP DATA/TOTAL lenGTH DEFINES Note #1'. ********************************************************************************************************* */ /* See Note #1. */ #define NET_TCP_MAX_SEG_SIZE_DFLT (NET_IP_MAX_DATAGRAM_SIZE_DFLT - NET_IP_HDR_SIZE_MIN - NET_TCP_HDR_SIZE_MIN) #define NET_TCP_MAX_SEG_SIZE_DFLT_RX NET_TCP_DATA_len_MAX /* See Note #1b1. */ #define NET_TCP_MAX_SEG_SIZE_DFLT_TX NET_TCP_MAX_SEG_SIZE_DFLT /* See Note #1b2. */ #define NET_TCP_MAX_SEG_SIZE_NONE 0u #define NET_TCP_MAX_SEG_SIZE_MIN NET_TCP_MAX_SEG_SIZE_DFLT #define NET_TCP_MAX_SEG_SIZE_MAX NET_TCP_DATA_len_MAX #define NET_TCP_SEG_len_MIN NET_TCP_DATA_len_MIN #define NET_TCP_SEG_len_MAX NET_TCP_DATA_len_MAX #define NET_TCP_SEG_len_SYNC 1u #define NET_TCP_SEG_len_FIN 1u #define NET_TCP_SEG_len_CLOSE NET_TCP_SEG_len_FIN #define NET_TCP_SEG_len_ACK 0u #define NET_TCP_SEG_len_RESET 0u #define NET_TCP_SEG_len_PROBE 0u #define NET_TCP_DATA_len_TX_SYNC 0u #define NET_TCP_DATA_len_TX_FIN 0u #define NET_TCP_DATA_len_TX_CLOSE NET_TCP_DATA_len_TX_FIN #define NET_TCP_DATA_len_TX_ACK 0u #define NET_TCP_DATA_len_TX_PROBE_NO_DATA 0u #define NET_TCP_DATA_len_TX_PROBE_DATA 1u #define NET_TCP_DATA_len_TX_RESET 0u #define NET_TCP_TX_PROBE_DATA 0x00u /* ********************************************************************************************************* * TCP WINDOW SIZE DEFINES * * Note(s) : (1) Although NO RFC specifies the absolute minimum TCP connection window size value allowed, * RFC #793, Section 3.7 'Data Communication : Managing the Window' states that for "the * window ... there is an assumption that this is related to the currently available data * buffer space available for this connection". ********************************************************************************************************* */ #define NET_TCP_WIN_SIZE_NONE 0u #define NET_TCP_WIN_SIZE_MIN NET_TCP_MAX_SEG_SIZE_MIN #define NET_TCP_WIN_SIZE_MAX DEF_INT_16U_MAX_VAL /*$PAGE*/ /* ********************************************************************************************************* * TCP HEADER OPTIONS DEFINES * * Note(s) : (1) See the following RFC's for TCP options summary : * * (a) RFC # 793, Section 3.1 'Header Format : Options' * (b) RFC #1122; Sections 4.2.2.5, 4.2.2.6 * * (2) TCP option types are encoded in the first octet for each TCP option as follows : * * -------- * | TYPE | * -------- * * The TCP option type value determines the TCP option format : * * (a) The following TCP option types are single-octet TCP options -- i.e. the option type * octet is the ONLY octet for the TCP option. * * (1) TYPE = 0 End of Options List * (2) TYPE = 1 No Operation * * * (b) All other TCP options MUST be multi-octet TCP options (see RFC #1122, Section 4.2.2.5) : * * ------------------------------ * | TYPE | len | TCP OPT | * ------------------------------ * * where * TYPE Indicates the specific TCP option type * len Indicates the total TCP option length, in octets, including * the option type & the option length octets * TCP OPT Additional TCP option octets, if any, that contain the remaining * TCP option information * * The following TCP option types are multi-octet TCP options where the option's second * octet specify the total TCP option length, in octets, including the option type & the * option length octets : * * (1) TYPE = 2 Maximum Segment Size See RFC # 793, Section 3.1 'Header Format : * Options : Maximum Segment Size'; * RFC #1122, Section 4.2.2.6; * RFC # 879, Section 3 * * (2) TYPE = 3 Window Scale See 'net_tcp.h Note #1c1' * (3) TYPE = 4 SACK Allowed See 'net_tcp.h Note #1c2' * (4) TYPE = 5 SACK Option See 'net_tcp.h Note #1c2' * (5) TYPE = 6 Echo Request See 'net_tcp.h Note #1c3' * (6) TYPE = 7 Echo Reply See 'net_tcp.h Note #1c3' * (7) TYPE = 8 Timestamp See 'net_tcp.h Note #1c4' * * (3) TCP header allows for a maximum option list length of 40 octets : * * NET_TCP_HDR_OPT_SIZE_MAX = NET_TCP_HDR_SIZE_MAX - NET_TCP_HDR_SIZE_MIN * * = 60 - 20 * * = 40 * * (4) 'NET_TCP_OPT_SIZE' MUST be pre-defined PRIOR to all definitions that require TCP option * size data type. ********************************************************************************************************* */ /*$PAGE*/ #define NET_TCP_HDR_OPT_END_LIST 0u #define NET_TCP_HDR_OPT_NOP 1u #define NET_TCP_HDR_OPT_MAX_SEG_SIZE 2u #define NET_TCP_HDR_OPT_WIN_SCALE 3u #define NET_TCP_HDR_OPT_SACK_PERMIT 4u #define NET_TCP_HDR_OPT_SACK 5u #define NET_TCP_HDR_OPT_ECHO_REQ 6u #define NET_TCP_HDR_OPT_ECHO_REPLY 7u #define NET_TCP_HDR_OPT_TS 8u #define NET_TCP_HDR_OPT_PAD NET_TCP_HDR_OPT_END_LIST #define NET_TCP_HDR_OPT_len_END_LIST 1u #define NET_TCP_HDR_OPT_len_NOP 1u #define NET_TCP_HDR_OPT_len_MAX_SEG_SIZE 4u #define NET_TCP_HDR_OPT_len_WIN_SCALE 3u #define NET_TCP_HDR_OPT_len_SACK_PERMIT 2u #define NET_TCP_HDR_OPT_len_ECHO_REQ 6u #define NET_TCP_HDR_OPT_len_ECHO_REPLY 6u #define NET_TCP_HDR_OPT_len_TS 10u #define NET_TCP_HDR_OPT_len_SACK_MIN 6u #define NET_TCP_HDR_OPT_len_SACK_MAX 38u #define NET_TCP_HDR_OPT_len_MIN 1u #define NET_TCP_HDR_OPT_len_MIN_len 2u #define NET_TCP_HDR_OPT_len_MAX 38u typedef CPU_INT32U NET_TCP_OPT_SIZE; /* TCP opt size data type (see Note #4). */ #define NET_TCP_HDR_OPT_SIZE_WORD (sizeof(NET_TCP_OPT_SIZE)) #define NET_TCP_HDR_OPT_SIZE_MAX (NET_TCP_HDR_SIZE_MAX - NET_TCP_HDR_SIZE_MIN) #define NET_TCP_HDR_OPT_NBR_MIN 0u #define NET_TCP_HDR_OPT_NBR_MAX (NET_TCP_HDR_OPT_SIZE_MAX / NET_TCP_HDR_OPT_SIZE_WORD) #define NET_TCP_HDR_OPT_IX NET_TCP_HDR_SIZE_MIN /*$PAGE*/ /* ********************************************************************************************************* * TCP OPTION CONFIGURATION TYPE DEFINES * * Note(s) : (1) NET_TCP_OPT_CFG_TYPE_&&& #define values specifically chosen as ASCII representations of * the TCP option configuration types. Memory displays of TCP option configuration buffers * will display the TCP option configuration TYPEs with their chosen ASCII names. ********************************************************************************************************* */ /* ---------------- TCP OPT CFG TYPES ----------------- */ #if (CPU_CFG_ENDIAN_TYPE == CPU_ENDIAN_TYPE_BIG) #define NET_TCP_OPT_CFG_TYPE_NONE 0x4E4F4E45u /* "NONE" in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_MAX_SEG_SIZE 0x4D535320u /* "MSS " in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_WIN_SCALE 0x57494E20u /* "WIN " in ASCII (see 'net_tcp.h Note #1c1'). */ #define NET_TCP_OPT_CFG_TYPE_SACK_PERMIT 0x53434B50u /* "SCKP" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_SACK 0x5341434Bu /* "SACK" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REQ 0x45524551u /* "EREQ" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REPLY 0x4543484Fu /* "ECHO" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_TS 0x54532020u /* "TS " in ASCII (see 'net_tcp.h Note #1c4'). */ #else #if (CPU_CFG_DATA_SIZE == CPU_WORD_SIZE_32) #define NET_TCP_OPT_CFG_TYPE_NONE 0x454E4F4Eu /* "NONE" in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_MAX_SEG_SIZE 0x2053534Du /* "MSS " in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_WIN_SCALE 0x204E4957u /* "WIN " in ASCII (see 'net_tcp.h Note #1c1'). */ #define NET_TCP_OPT_CFG_TYPE_SACK_PERMIT 0x504B4353u /* "SCKP" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_SACK 0x4B434153u /* "SACK" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REQ 0x51455245u /* "EREQ" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REPLY 0x4F484345u /* "ECHO" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_TS 0x20205354u /* "TS " in ASCII (see 'net_tcp.h Note #1c4'). */ #elif (CPU_CFG_DATA_SIZE == CPU_WORD_SIZE_16) #define NET_TCP_OPT_CFG_TYPE_NONE 0x4F4E454Eu /* "NONE" in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_MAX_SEG_SIZE 0x534D2053u /* "MSS " in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_WIN_SCALE 0x4957204Eu /* "WIN " in ASCII (see 'net_tcp.h Note #1c1'). */ #define NET_TCP_OPT_CFG_TYPE_SACK_PERMIT 0x4353504Bu /* "SCKP" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_SACK 0x41534B43u /* "SACK" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REQ 0x52455145u /* "EREQ" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REPLY 0x43454F48u /* "ECHO" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_TS 0x53542020u /* "TS " in ASCII (see 'net_tcp.h Note #1c4'). */ #else /* Dflt CPU_WORD_SIZE_08. */ #define NET_TCP_OPT_CFG_TYPE_NONE 0x4E4F4E45u /* "NONE" in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_MAX_SEG_SIZE 0x4D535320u /* "MSS " in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_WIN_SCALE 0x57494E20u /* "WIN " in ASCII (see 'net_tcp.h Note #1c1'). */ #define NET_TCP_OPT_CFG_TYPE_SACK_PERMIT 0x53434B50u /* "SCKP" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_SACK 0x5341434Bu /* "SACK" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REQ 0x45524551u /* "EREQ" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REPLY 0x4543484Fu /* "ECHO" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_TS 0x54532020u /* "TS " in ASCII (see 'net_tcp.h Note #1c4'). */ #endif #endif /*$PAGE*/ /* ********************************************************************************************************* * TCP CONNECTION TIMEOUT DEFINES * * Note(s) : (1) (a) (1) RFC #1122, Section 4.2.2.13 'DISCUSSION' states that "the graceful close algorithm * of TCP requires that the connection state remain defined on (at least) one end of * the connection, for a timeout period of 2xMSL ... During this period, the (remote * socket, local socket) pair that defines the connection is busy and cannot be reused". * * (2) The following sections reiterate that the TIME-WAIT state timeout scalar is two * maximum segment lifetimes (2 MSL) : * * (A) RFC #793, Section 3.9 'Event Processing : SEGMENT ARRIVES : * Check Sequence Number : TIME-WAIT STATE' * (B) RFC #793, Section 3.9 'Event Processing : SEGMENT ARRIVES : * Check FIN Bit : TIME-WAIT STATE' * * (b) (1) RFC #793, Section 3.3 'Sequence Numbers : Knowing When to Keep Quiet' states that * "the Maximum Segment Lifetime (MSL) is ... to be 2 minutes. This is an engineering * choice, and may be changed if experience indicates it is desirable to do so". * * (2) Microsoft Corporation's Windows XP defaults MSL to 15 seconds. ********************************************************************************************************* */ /* Max seg timeout (see Note #1b) : */ #define NET_TCP_CONN_TIMEOUT_MAX_SEG_MIN_SEC ( 0u ) /* ... min = 0 seconds */ #define NET_TCP_CONN_TIMEOUT_MAX_SEG_MAX_SEC ( 2u * DEF_TIME_NBR_SEC_PER_MIN) /* ... max = 2 minutes */ #define NET_TCP_CONN_TIMEOUT_MAX_SEG_DFLT_SEC ( 15u ) /* ... dflt = 15 seconds */ #define NET_TCP_CONN_TIMEOUT_MAX_SEG_SCALAR 2u /* ... scalar (see Note #1a). */ #define NET_TCP_CONN_TIMEOUT_CONN_DFLT_SEC (120u * DEF_TIME_NBR_SEC_PER_MIN) /* Dflt conn timeout = 120 minutes */ #define NET_TCP_CONN_TIMEOUT_USER_DFLT_SEC ( 30u * DEF_TIME_NBR_SEC_PER_MIN) /* Dflt user timeout = 30 minutes */ /*$PAGE*/ /* ********************************************************************************************************* * TCP CONNECTION STATES * * Note(s) : (1) See the following RFC's for TCP state machine summary : * * (a) RFC # 793; Sections 3.2, 3.4, 3.5, 3.9 * (b) RFC #1122; Sections 4.2.2.8, 4.2.2.10, 4.2.2.11, 4.2.2.13, 4.2.2.18, 4.2.2.20 * * (2) (a) #### Additional closing-data-available state used for closing connections to allow the * application layer to receive any remaining data. * * See also 'net_tcp.c NetTCP_RxPktConnHandlerFinWait1() Note #2f5A2', * 'net_tcp.c NetTCP_RxPktConnHandlerFinWait2() Note #2f5B', * 'net_tcp.c NetTCP_RxPktConnHandlerClosing() Note #2d2B2a1B', * & 'net_tcp.c NetTCP_RxPktConnHandlerLastAck() Note #2d2A1b'. ********************************************************************************************************* */ #define NET_TCP_CONN_STATE_NONE 0u #define NET_TCP_CONN_STATE_FREE 1u #define NET_TCP_CONN_STATE_CLOSED 10u #define NET_TCP_CONN_STATE_LISTEN 20u #define NET_TCP_CONN_STATE_SYNC_RXD 30u #define NET_TCP_CONN_STATE_SYNC_RXD_PASSIVE 31u #define NET_TCP_CONN_STATE_SYNC_RXD_ACTIVE 32u #define NET_TCP_CONN_STATE_SYNC_TXD 35u #define NET_TCP_CONN_STATE_CONN 40u #define NET_TCP_CONN_STATE_FIN_WAIT_1 50u #define NET_TCP_CONN_STATE_FIN_WAIT_2 51u #define NET_TCP_CONN_STATE_CLOSING 52u #define NET_TCP_CONN_STATE_TIME_WAIT 53u #define NET_TCP_CONN_STATE_CLOSE_WAIT 55u #define NET_TCP_CONN_STATE_LAST_ACK 56u #define NET_TCP_CONN_STATE_CLOSING_DATA_AVAIL 59u /* See Note #2a. */ /* ********************************************************************************************************* * TCP CONNECTION QUEUE STATES ********************************************************************************************************* */ #define NET_TCP_RX_Q_STATE_NONE 0u #define NET_TCP_RX_Q_STATE_CLOSED 100u #define NET_TCP_RX_Q_STATE_CLOSING 101u #define NET_TCP_RX_Q_STATE_SYNC 110u #define NET_TCP_RX_Q_STATE_CONN 111u #define NET_TCP_TX_Q_STATE_NONE 0u #define NET_TCP_TX_Q_STATE_CLOSED 200u #define NET_TCP_TX_Q_STATE_CLOSING 201u #define NET_TCP_TX_Q_STATE_SYNC 210u #define NET_TCP_TX_Q_STATE_CONN 211u #define NET_TCP_TX_Q_STATE_SUSPEND 215u #define NET_TCP_TX_Q_STATE_CLOSED_SUSPEND 220u #define NET_TCP_TX_Q_STATE_CLOSING_SUSPEND 221u /*$PAGE*/ /* ********************************************************************************************************* * TCP CONNECTION CODE DEFINES **************
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以后再也不用担心写爬虫ip被封,不用担心没钱买代理ip的烦恼了 在使用python写爬虫时候,你会遇到所要爬取的网站有反爬取技术比如用同一个IP反复爬取同一个网页,很可能会被封。如何有效的解决这个问题呢?我们可以使用代理ip,来设置代理ip池。 现在教大家一个可获取大量免费有效快速的代理ip方法,我们访问西刺免费代理ip网址 这里面提供了许多代理ip,但是我们尝试过后会发现并不是每一个都是有效的。所以我们现在所要做的就是从里面提供的筛选出有效快速稳定的ip。 以下介绍的免费获取代理ip池的方法: 优点:免费、数量多、有效、速度快 缺点:需要定期筛选 主要思路: 从网址上爬取ip地址并存储 验证ip是否能使用-(随机访问网址判断响应码) 格式化ip地址 代码如下: 1.导入包 import requests from lxml import etree import time 1 2 3 2.获取西刺免费代理ip网址上的代理ip def get_all_proxy(): url = 'http://www.xicidaili.com/nn/1' headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36', } response = requests.get(url, headers=headers) html_ele = etree.HTML(response.text) ip_eles = html_ele.xpath('//table[@id="ip_list"]/tr/td[2]/text()') port_ele = html_ele.xpath('//table[@id="ip_list"]/tr/td[3]/text()') proxy_list = [] for i in range(0,len(ip_eles)): proxy_str = 'http://' + ip_eles[i] + ':' + port_ele[i] proxy_list.append(proxy_str) return proxy_list 1 2 3 4 5 6 7 8 9 10 11 12 13 14 3.验证获取的ip def check_all_proxy(proxy_list): valid_proxy_list = [] for proxy in proxy_list: url = 'http://www.baidu.com/' proxy_dict = { 'http': proxy } try: start_time = time.time() response = requests.get(url, proxies=proxy_dict, timeout=5) if response.status_code == 200: end_time = time.time() print('代理可用:' + proxy) print('耗时:' + str(end_time - start_time)) valid_proxy_list.append(proxy) else: print('代理超时') except: print('代理不可用--------------->'+proxy) return valid_proxy_list 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 4.输出获取ip池 if __name__ == '__main__': proxy_list = get_all_proxy() valid_proxy_list = check_all_proxy(proxy_list) print('--'*30) print(valid_proxy_list) 1 2 3 4 5 技术能力有限欢迎提出意见,保证积极向上不断学习 ———————————————— 版权声明:本文为CSDN博主「彬小二」的原创文章,遵循 CC 4.0 BY-SA 版权协议,转载请附上原文出处链接及本声明。 原文链接:https://blog.csdn.net/qq_39884947/article/details/86609930
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Python 最好的品质之一是一致性。当你使用 Python 工作一会儿后,就会开始理解 Python 语言,并能正确猜测出对你来说全新的语言特征。然而,如果你带着来自其他面向对象语言的经验进入 Python 的世界,会对 len(colleciton) 而不是 collection.len() 写法觉得不适。当你进一步理解这种不适感背后的原因之后,会发现这个原因,和它所代表的庞大的设计思想,是形成我们通常说的“Python 风格”(Pythonic)的关键。这种设计思想完全体现在 Python 的数据模型上,而数据模型所描述的 API,为使用最地道的语言特性来构建你自己的对象提供了工具。数据模型其实是对 Python 框架的描述,它规范了这门语言自身构建模块的接口,这些模块包括但不限于序列、迭代器、函数、类和上下文管理器。
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