首页 > C/C++ > Linux中socket错误编码表errno
2016
12-26

Linux中socket错误编码表errno

最近在网络编程使用的过程中,发现errno会经常使用。因此决定在此做个留用,以备以后使用。。。

虽然errno是非线程安全的,但是可以通过几种机制保证其安全。。

最近在使用的过程中获得了errno,程序无法执行,也不知道如何解决问题。因此,理解每一个返回的errno整数值的含义是很重要的。。

这个我们可以通过strerror函数来实现。。

strerror(返回整数errno对应的错误原因的描述字符串)

所需头文件:   #include<string.h>
函数声明:    char * strerror(int errnum);

输入:       整数errno

输出:       返回描述错误原因的字符串指针
功能:      用来依参数errnum 的错误代码来查询其错误原因的描述字符串,然后将该字符串指针返回。
示例:

#include <string.h>
#include <stdio.h>
#define NUM    150
int main(void)
{
    int i;    
    for ( i=0; i<NUM; i++ )
    {
        printf( "%d:%s\n", i, strerror(i) );
    }       
    return 0;
}

运行结果:

  1. 0:Success
  2. 1:Operation not permitted
  3. 2:No such file or directory
  4. 3:No such process
  5. 4:Interrupted system call
  6. 5:Input/output error
  7. 6:No such device or address
  8. 7:Argument list too long
  9. 8:Exec format error
  10. 9:Bad file descriptor
  11. 10:No child processes
  12. 11:Resource temporarily unavailable
  13. 12:Cannot allocate memory
  14. 13:Permission denied
  15. 14:Bad address
  16. 15:Block device required
  17. 16:Device or resource busy
  18. 17:File exists
  19. 18:Invalid cross-device link
  20. 19:No such device
  21. 20:Not a directory
  22. 21:Is a directory
  23. 22:Invalid argument
  24. 23:Too many open files in system
  25. 24:Too many open files
  26. 25:Inappropriate ioctl for device
  27. 26:Text file busy
  28. 27:File too large
  29. 28:No space left on device
  30. 29:Illegal seek
  31. 30:Read-only file system
  32. 31:Too many links
  33. 32:Broken pipe
  34. 33:Numerical argument out of domain
  35. 34:Numerical result out of range
  36. 35:Resource deadlock avoided
  37. 36:File name too long
  38. 37:No locks available
  39. 38:Function not implemented
  40. 39:Directory not empty
  41. 40:Too many levels of symbolic links
  42. 41:Unknown error 41
  43. 42:No message of desired type
  44. 43:Identifier removed
  45. 44:Channel number out of range
  46. 45:Level 2 not synchronized
  47. 46:Level 3 halted
  48. 47:Level 3 reset
  49. 48:Link number out of range
  50. 49:Protocol driver not attached
  51. 50:No CSI structure available
  52. 51:Level 2 halted
  53. 52:Invalid exchange
  54. 53:Invalid request descriptor
  55. 54:Exchange full
  56. 55:No anode
  57. 56:Invalid request code
  58. 57:Invalid slot
  59. 58:Unknown error 58
  60. 59:Bad font file format
  61. 60:Device not a stream
  62. 61:No data available
  63. 62:Timer expired
  64. 63:Out of streams resources
  65. 64:Machine is not on the network
  66. 65:Package not installed
  67. 66:Object is remote
  68. 67:Link has been severed
  69. 68:Advertise error
  70. 69:Srmount error
  71. 70:Communication error on send
  72. 71:Protocol error
  73. 72:Multihop attempted
  74. 73:RFS specific error
  75. 74:Bad message
  76. 75:Value too large for defined data type
  77. 76:Name not unique on network
  78. 77:File descriptor in bad state
  79. 78:Remote address changed
  80. 79:Can not access a needed shared library
  81. 80:Accessing a corrupted shared library
  82. 81:.lib section in a.out corrupted
  83. 82:Attempting to link in too many shared libraries
  84. 83:Cannot exec a shared library directly
  85. 84:Invalid or incomplete multibyte or wide character
  86. 85:Interrupted system call should be restarted
  87. 86:Streams pipe error
  88. 87:Too many users
  89. 88:Socket operation on non-socket
  90. 89:Destination address required
  91. 90:Message too long
  92. 91:Protocol wrong type for socket
  93. 92:Protocol not available
  94. 93:Protocol not supported
  95. 94:Socket type not supported
  96. 95:Operation not supported
  97. 96:Protocol family not supported
  98. 97:Address family not supported by protocol
  99. 98:Address already in use
  100. 99:Cannot assign requested address
  101. 100:Network is down
  102. 101:Network is unreachable
  103. 102:Network dropped connection on reset
  104. 103:Software caused connection abort
  105. 104:Connection reset by peer
  106. 105:No buffer space available
  107. 106:Transport endpoint is already connected
  108. 107:Transport endpoint is not connected
  109. 108:Cannot send after transport endpoint shutdown
  110. 109:Too many references: cannot splice
  111. 110:Connection timed out
  112. 111:Connection refused
  113. 112:Host is down
  114. 113:No route to host
  115. 114:Operation already in progress
  116. 115:Operation now in progress
  117. 116:Stale NFS file handle
  118. 117:Structure needs cleaning
  119. 118:Not a XENIX named type file
  120. 119:No XENIX semaphores available
  121. 120:Is a named type file
  122. 121:Remote I/O error
  123. 122:Disk quota exceeded
  124. 123:No medium found
  125. 124:Wrong medium type
  126. 125:Operation canceled
  127. 126:Required key not available
  128. 127:Key has expired
  129. 128:Key has been revoked
  130. 129:Key was rejected by service
  131. 130:Owner died
  132. 131:State not recoverable
  133. 132:Unknown error 132
  134. 133:Unknown error 133
  135. 134:Unknown error 134
  136. 135:Unknown error 135
  137. 136:Unknown error 136
  138. 137:Unknown error 137
  139. 138:Unknown error 138
  140. 139:Unknown error 139
  141. 140:Unknown error 140
  142. 141:Unknown error 141
  143. 142:Unknown error 142
  144. 143:Unknown error 143
  145. 144:Unknown error 144
  146. 145:Unknown error 145
  147. 146:Unknown error 146
  148. 147:Unknown error 147
  149. 148:Unknown error 148
  150. 149:Unknown error 149

 

通过这个我们终于理解errno的含义了。。那天做的一个使用非阻塞connect式爬虫,无论如何也不好使,也不知道怎么解决,程序并没有出现段错误,最终定位在write套接字时就退出,而通过FD_ISSET测试此套接字可写,于是不知道怎么解决了。通过捕捉errno值,发现是104.而如果当时我可以知道errno=104是指“Connection reset by peer”,那么我就知道了网络爬虫式客户端需要增加对于SIGPIPE信号的处理了。。因为SIGPIPE默认处理方式是退出,改成自己添加信号处理函数或者使用忽略就可以了。。。

所以列出这些信息,一方面能对大家有所帮助,另一方面方便以后查询。

  1. #ifndef _ASM_GENERIC_ERRNO_BASE_H
  2. #define _ASM_GENERIC_ERRNO_BASE_H
  3.  
  4. #define EPERM            1      /* Operation not permitted */
  5. #define ENOENT           2      /* No such file or directory */
  6. #define ESRCH            3      /* No such process */
  7. #define EINTR            4      /* Interrupted system call */
  8. #define EIO              5      /* I/O error */
  9. #define ENXIO            6      /* No such device or address */
  10. #define E2BIG            7      /* Argument list too long */
  11. #define ENOEXEC          8      /* Exec format error */
  12. #define EBADF            9      /* Bad file number */
  13. #define ECHILD          10      /* No child processes */
  14. #define EAGAIN          11      /* Try again */
  15. #define ENOMEM          12      /* Out of memory */
  16. #define EACCES          13      /* Permission denied */
  17. #define EFAULT          14      /* Bad address */
  18. #define ENOTBLK         15      /* Block device required */
  19. #define EBUSY           16      /* Device or resource busy */
  20. #define EEXIST          17      /* File exists */
  21. #define EXDEV           18      /* Cross-device link */
  22. #define ENODEV          19      /* No such device */
  23. #define ENOTDIR         20      /* Not a directory */
  24. #define EISDIR          21      /* Is a directory */
  25. #define EINVAL          22      /* Invalid argument */
  26. #define ENFILE          23      /* File table overflow */
  27. #define EMFILE          24      /* Too many open files */
  28. #define ENOTTY          25      /* Not a typewriter */
  29. #define ETXTBSY         26      /* Text file busy */
  30. #define EFBIG           27      /* File too large */
  31. #define ENOSPC          28      /* No space left on device */
  32. #define ESPIPE          29      /* Illegal seek */
  33. #define EROFS           30      /* Read-only file system */
  34. #define EMLINK          31      /* Too many links */
  35. #define EPIPE           32      /* Broken pipe */
  36. #define EDOM            33      /* Math argument out of domain of func */
  37. #define ERANGE          34      /* Math result not representable */
  38.  
  39. #endif
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作者:liujg
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