Linux中系统调用的错误都存储于 errno中，errno由操作系统维护，存储就近发生的错误，即下一次的错误码会覆盖掉上一次的错误。

错误码描述如下 0 表示成功

errno: 0 Success

errno: 1 Operation not permitted

errno: 2 No such file or directory

errno: 3 No such process

errno: 4 Interrupted system call

errno: 5 Input/output error

errno: 6 No such device or address

errno: 7 Argument list too long

errno: 8 Exec format error

errno: 9 Bad file descriptor

errno: 10 No child processes

errno: 11 Resource temporarily unavailable

errno: 12 Cannot allocate memory

errno: 13 Permission denied

errno: 14 Bad address

errno: 15 Block device required

errno: 16 Device or resource busy

errno: 17 File exists

errno: 18 Invalid cross-device link

errno: 19 No such device

errno: 20 Not a directory

errno: 21 Is a directory

errno: 22 Invalid argument

errno: 23 Too many open files in system

errno: 24 Too many open files

errno: 25 Inappropriate ioctl for device

errno: 26 Text file busy

errno: 27 File too large

errno: 28 No space left on device

errno: 29 Illegal seek

errno: 30 Read-only file system

errno: 31 Too many links

errno: 32 Broken pipe

errno: 33 Numerical argument out of domain

errno: 34 Numerical result out of range

errno: 35 Resource deadlock avoided

errno: 36 File name too long

errno: 37 No locks available

errno: 38 Function not implemented

errno: 39 Directory not empty

errno: 40 Too many levels of symbolic links

errno: 41 Unknown error 41

errno: 42 No message of desired type

errno: 43 Identifier removed

errno: 44 Channel number out of range

errno: 45 Level 2 not synchronized

errno: 46 Level 3 halted

errno: 47 Level 3 reset

errno: 48 Link number out of range

errno: 49 Protocol driver not attached

errno: 50 No CSI structure available

errno: 51 Level 2 halted

errno: 52 Invalid exchange

errno: 53 Invalid request descriptor

errno: 54 Exchange full

errno: 55 No anode

errno: 56 Invalid request code

errno: 57 Invalid slot

errno: 58 Unknown error 58

errno: 59 Bad font file format

errno: 60 Device not a stream

errno: 61 No data available

errno: 62 Timer expired

errno: 63 Out of streams resources

errno: 64 Machine is not on the network

errno: 65 Package not installed

errno: 66 Object is remote

errno: 67 Link has been severed

errno: 68 Advertise error

errno: 69 Srmount error

errno: 70 Communication error on send

errno: 71 Protocol error

errno: 72 Multihop attempted

errno: 73 RFS specific error

errno: 74 Bad message

errno: 75 Value too large for defined data type

errno: 76 Name not unique on network

errno: 77 File descriptor in bad state

errno: 78 Remote address changed

errno: 79 Can not access a needed shared library

errno: 80 Accessing a corrupted shared library

errno: 81 .lib section in a.out corrupted

errno: 82 Attempting to link in too many shared libraries

errno: 83 Cannot exec a shared library directly

errno: 84 Invalid or incomplete multibyte or wide character

errno: 85 Interrupted system call should be restarted

errno: 86 Streams pipe error

errno: 87 Too many users

errno: 88 Socket operation on non-socket

errno: 89 Destination address required

errno: 90 Message too long

errno: 91 Protocol wrong type for socket

errno: 92 Protocol not available

errno: 93 Protocol not supported

errno: 94 Socket type not supported

errno: 95 Operation not supported

errno: 96 Protocol family not supported

errno: 97 Address family not supported by protocol

errno: 98 Address already in use

errno: 99 Cannot assign requested address

errno: 100 Network is down

errno: 101 Network is unreachable

errno: 102 Network dropped connection on reset

errno: 103 Software caused connection abort

errno: 104 Connection reset by peer

errno: 105 No buffer space available

errno: 106 Transport endpoint is already connected

errno: 107 Transport endpoint is not connected

errno: 108 Cannot send after transport endpoint shutdown

errno: 109 Too many references: cannot splice

errno: 110 Connection timed out

errno: 111 Connection refused

errno: 112 Host is down

errno: 113 No route to host

errno: 114 Operation already in progress

errno: 115 Operation now in progress

errno: 116 Stale file handle

errno: 117 Structure needs cleaning

errno: 118 Not a XENIX named type file

errno: 119 No XENIX semaphores available

errno: 120 Is a named type file

errno: 121 Remote I/O error

errno: 122 Disk quota exceeded

errno: 123 No medium found

errno: 124 Wrong medium type

errno: 125 Operation canceled

errno: 126 Required key not available

errno: 127 Key has expired

errno: 128 Key has been revoked

errno: 129 Key was rejected by service

errno: 130 Owner died

errno: 131 State not recoverable

errno: 132 Operation not possible due to RF-kill

errno: 133 Memory page has hardware error

errno: 134~255 unknown error!

Linux中，在头文件 /usr/include/asm-generic/errno-base.h 对基础常用errno进行了宏定义：

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

在 /usr/include/asm-asm-generic/errno.h 中，对剩余的errno做了宏定义：

#ifndef _ASM_GENERIC_ERRNO_H#define _ASM_GENERIC_ERRNO_H#include #define EDEADLK 35 /* Resource deadlock would occur */#define ENAMETOOLONG 36 /* File name too long */#define ENOLCK 37 /* No record locks available */#define ENOSYS 38 /* Function not implemented */#define ENOTEMPTY 39 /* Directory not empty */#define ELOOP 40 /* Too many symbolic links encountered */#define EWOULDBLOCK EAGAIN /* Operation would block */#define ENOMSG 42 /* No message of desired type */#define EIDRM 43 /* Identifier removed */#define ECHRNG 44 /* Channel number out of range */#define EL2NSYNC 45 /* Level 2 not synchronized */#define EL3HLT 46 /* Level 3 halted */#define EL3RST 47 /* Level 3 reset */#define ELNRNG 48 /* Link number out of range */#define EUNATCH 49 /* Protocol driver not attached */#define ENOCSI 50 /* No CSI structure available */#define EL2HLT 51 /* Level 2 halted */#define EBADE 52 /* Invalid exchange */#define EBADR 53 /* Invalid request descriptor */#define EXFULL 54 /* Exchange full */#define ENOANO 55 /* No anode */#define EBADRQC 56 /* Invalid request code */#define EBADSLT 57 /* Invalid slot */#define EDEADLOCK EDEADLK#define EBFONT 59 /* Bad font file format */#define ENOSTR 60 /* Device not a stream */#define ENODATA 61 /* No data available */#define ETIME 62 /* Timer expired */#define ENOSR 63 /* Out of streams resources */#define ENONET 64 /* Machine is not on the network */#define ENOPKG 65 /* Package not installed */#define EREMOTE 66 /* Object is remote */#define ENOLINK 67 /* Link has been severed */#define EADV 68 /* Advertise error */#define ESRMNT 69 /* Srmount error */#define ECOMM 70 /* Communication error on send */#define EPROTO 71 /* Protocol error */#define EMULTIHOP 72 /* Multihop attempted */#define EDOTDOT 73 /* RFS specific error */#define EBADMSG 74 /* Not a data message */#define EOVERFLOW 75 /* Value too large for defined data type */#define ENOTUNIQ 76 /* Name not unique on network */#define EBADFD 77 /* File descriptor in bad state */#define EREMCHG 78 /* Remote address changed */#define ELIBACC 79 /* Can not access a needed shared library */#define ELIBBAD 80 /* Accessing a corrupted shared library */#define ELIBSCN 81 /* .lib section in a.out corrupted */#define ELIBMAX 82 /* Attempting to link in too many shared libraries */#define ELIBEXEC 83 /* Cannot exec a shared library directly */#define EILSEQ 84 /* Illegal byte sequence */#define ERESTART 85 /* Interrupted system call should be restarted */#define ESTRPIPE 86 /* Streams pipe error */#define EUSERS 87 /* Too many users */#define ENOTSOCK 88 /* Socket operation on non-socket */#define EDESTADDRREQ 89 /* Destination address required */#define EMSGSIZE 90 /* Message too long */#define EPROTOTYPE 91 /* Protocol wrong type for socket */#define ENOPROTOOPT 92 /* Protocol not available */#define EPROTONOSUPPORT 93 /* Protocol not supported */#define ESOCKTNOSUPPORT 94 /* Socket type not supported */#define EOPNOTSUPP 95 /* Operation not supported on transport endpoint */#define EPFNOSUPPORT 96 /* Protocol family not supported */#define EAFNOSUPPORT 97 /* Address family not supported by protocol */#define EADDRINUSE 98 /* Address already in use */#define EADDRNOTAVAIL 99 /* Cannot assign requested address */#define ENETDOWN 100 /* Network is down */#define ENETUNREACH 101 /* Network is unreachable */#define ENETRESET 102 /* Network dropped connection because of reset */#define ECONNABORTED 103 /* Software caused connection abort */#define ECONNRESET 104 /* Connection reset by peer */#define ENOBUFS 105 /* No buffer space available */#define EISCONN 106 /* Transport endpoint is already connected */#define ENOTCONN 107 /* Transport endpoint is not connected */#define ESHUTDOWN 108 /* Cannot send after transport endpoint shutdown */#define ETOOMANYREFS 109 /* Too many references: cannot splice */#define ETIMEDOUT 110 /* Connection timed out */#define ECONNREFUSED 111 /* Connection refused */#define EHOSTDOWN 112 /* Host is down */#define EHOSTUNREACH 113 /* No route to host */#define EALREADY 114 /* Operation already in progress */#define EINPROGRESS 115 /* Operation now in progress */#define ESTALE 116 /* Stale file handle */#define EUCLEAN 117 /* Structure needs cleaning */#define ENOTNAM 118 /* Not a XENIX named type file */#define ENAVAIL 119 /* No XENIX semaphores available */#define EISNAM 120 /* Is a named type file */#define EREMOTEIO 121 /* Remote I/O error */#define EDQUOT 122 /* Quota exceeded */#define ENOMEDIUM 123 /* No medium found */#define EMEDIUMTYPE 124 /* Wrong medium type */#define ECANCELED 125 /* Operation Canceled */#define ENOKEY 126 /* Required key not available */#define EKEYEXPIRED 127 /* Key has expired */#define EKEYREVOKED 128 /* Key has been revoked */#define EKEYREJECTED 129 /* Key was rejected by service *//* for robust mutexes */#define EOWNERDEAD 130 /* Owner died */#define ENOTRECOVERABLE 131 /* State not recoverable */#define ERFKILL 132 /* Operation not possible due to RF-kill */#define EHWPOISON 133 /* Memory page has hardware error */#endif