在Linux文件操作以及更底层的IO操作出错的情况下，经常会为该如何返回合适的错误代码而纠结。另外在阅读代码的时候，可能会碰到很多种错误代码，因为不明白它的含义而迷惑。为此，有必要归纳整理一下常见的所有的出错代码及其对应的含义，既方便阅读代码时参考，又便于自己正确选用。

显然因为这些代码大都处在用户态，可能会有多个进程或者线程会用到它，因此通常把它们归纳一起放在同一个头文件里。在笔者的Linux中系统中，目前用到的宏的定义在下面的头文件里：

/usr/include/asm-generic/errno-base.h:

#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 */

此外，/usr/include/asm-generic/errno.h还有一部分常用到的出错代码在这里定义，可以看到它和上面定义的错误代码的代码是统一编号的。

#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 */

通过上面列举出来的所有文件和IO操作相关的错误代码可以看到，种类很多，数量不小，在我们实际的工程项目中，必须结合具体业务场景选则合适的错误代码，既要保证代码的含义和真是场景吻合，又要避免在不同的场景中使用了相同的错误代码。