Linux errno详解-白红宇

Linux errno详解

阅读量：7097 次

发布时间：2019-06-28

本文共 13294 字，大约阅读时间需要 44 分钟。

1. 错误码 / errno

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。

PS: 只有当系统调用或者调用lib函数时出错，才会置位errno！

查看系统中所有的errno所代表的含义，可以采用如下的代码：

/* Function: obtain the errno string*   char *strerror(int errno)*/#include 
    
     #include 
     
           //for strerror()//#include 
      
       int main(){    int tmp = 0;    for(tmp = 0; tmp <=256; tmp++)    {        printf("errno: %2d\t%s\n",tmp,strerror(tmp));    }    return 0;}

输出信息如下：

errno:  0       Successerrno:  1       Operation not permittederrno:  2       No such file or directoryerrno:  3       No such processerrno:  4       Interrupted system callerrno:  5       Input/output errorerrno:  6       No such device or addresserrno:  7       Argument list too longerrno:  8       Exec format errorerrno:  9       Bad file descriptorerrno: 10       No child processeserrno: 11       Resource temporarily unavailableerrno: 12       Cannot allocate memoryerrno: 13       Permission deniederrno: 14       Bad addresserrno: 15       Block device requirederrno: 16       Device or resource busyerrno: 17       File existserrno: 18       Invalid cross-device linkerrno: 19       No such deviceerrno: 20       Not a directoryerrno: 21       Is a directoryerrno: 22       Invalid argumenterrno: 23       Too many open files in systemerrno: 24       Too many open fileserrno: 25       Inappropriate ioctl for deviceerrno: 26       Text file busyerrno: 27       File too largeerrno: 28       No space left on deviceerrno: 29       Illegal seekerrno: 30       Read-only file systemerrno: 31       Too many linkserrno: 32       Broken pipeerrno: 33       Numerical argument out of domainerrno: 34       Numerical result out of rangeerrno: 35       Resource deadlock avoidederrno: 36       File name too longerrno: 37       No locks availableerrno: 38       Function not implementederrno: 39       Directory not emptyerrno: 40       Too many levels of symbolic linkserrno: 41       Unknown error 41errno: 42       No message of desired typeerrno: 43       Identifier removederrno: 44       Channel number out of rangeerrno: 45       Level 2 not synchronizederrno: 46       Level 3 haltederrno: 47       Level 3 reseterrno: 48       Link number out of rangeerrno: 49       Protocol driver not attachederrno: 50       No CSI structure availableerrno: 51       Level 2 haltederrno: 52       Invalid exchangeerrno: 53       Invalid request descriptorerrno: 54       Exchange fullerrno: 55       No anodeerrno: 56       Invalid request codeerrno: 57       Invalid sloterrno: 58       Unknown error 58errno: 59       Bad font file formaterrno: 60       Device not a streamerrno: 61       No data availableerrno: 62       Timer expirederrno: 63       Out of streams resourceserrno: 64       Machine is not on the networkerrno: 65       Package not installederrno: 66       Object is remoteerrno: 67       Link has been severederrno: 68       Advertise errorerrno: 69       Srmount errorerrno: 70       Communication error on senderrno: 71       Protocol errorerrno: 72       Multihop attemptederrno: 73       RFS specific errorerrno: 74       Bad messageerrno: 75       Value too large for defined data typeerrno: 76       Name not unique on networkerrno: 77       File descriptor in bad stateerrno: 78       Remote address changederrno: 79       Can not access a needed shared libraryerrno: 80       Accessing a corrupted shared libraryerrno: 81       .lib section in a.out corruptederrno: 82       Attempting to link in too many shared librarieserrno: 83       Cannot exec a shared library directlyerrno: 84       Invalid or incomplete multibyte or wide charactererrno: 85       Interrupted system call should be restartederrno: 86       Streams pipe errorerrno: 87       Too many userserrno: 88       Socket operation on non-socketerrno: 89       Destination address requirederrno: 90       Message too longerrno: 91       Protocol wrong type for socketerrno: 92       Protocol not availableerrno: 93       Protocol not supportederrno: 94       Socket type not supportederrno: 95       Operation not supportederrno: 96       Protocol family not supportederrno: 97       Address family not supported by protocolerrno: 98       Address already in useerrno: 99       Cannot assign requested addresserrno: 100      Network is downerrno: 101      Network is unreachableerrno: 102      Network dropped connection on reseterrno: 103      Software caused connection aborterrno: 104      Connection reset by peererrno: 105      No buffer space availableerrno: 106      Transport endpoint is already connectederrno: 107      Transport endpoint is not connectederrno: 108      Cannot send after transport endpoint shutdownerrno: 109      Too many references: cannot spliceerrno: 110      Connection timed outerrno: 111      Connection refusederrno: 112      Host is downerrno: 113      No route to hosterrno: 114      Operation already in progresserrno: 115      Operation now in progresserrno: 116      Stale file handleerrno: 117      Structure needs cleaningerrno: 118      Not a XENIX named type fileerrno: 119      No XENIX semaphores availableerrno: 120      Is a named type fileerrno: 121      Remote I/O errorerrno: 122      Disk quota exceedederrno: 123      No medium founderrno: 124      Wrong medium typeerrno: 125      Operation cancelederrno: 126      Required key not availableerrno: 127      Key has expirederrno: 128      Key has been revokederrno: 129      Key was rejected by serviceerrno: 130      Owner diederrno: 131      State not recoverableerrno: 132      Operation not possible due to RF-killerrno: 133      Memory page has hardware errorerrno: 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

2. 打印错误信息

1). 打印错误信息 / perror

作用：
打印系统错误信息
头文件：
#include 
       
函数原型：
void perror(const char *s)
参数：

s: 字符串提示符

输出形式：
const char *s: strerror(errno) //提示符：发生系统错误的原因

返回值：
无返回值