1函數名編輯
strerror, _strerror, _wcserror, __wcserror
2函數做用編輯
Get a system error message (strerror, _wcserror) or prints a user-supplied error message (_strerror, __wcserror).
3頭文件編輯
#include <string.h>
4函數原型編輯
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1
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char
*
strerror
(interrnum);
char
*_strerror(constchar*strErrMsg);
wchar_t
*_wcserror(interrnum);
wchar_t
*__wcserror(constwchar_t*strErrMsg)
|
參數：
errnum：錯誤標號，一般用errno(標準錯誤號，定義在errno.h中)
Error number.
strErrMsg
User-supplied message.
返回：
5舉例編輯
例一：
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15
16
17
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#include<stdio.h>
#include<string.h>
#include<errno.h>
#include<stdlib.h>
intmain(
void
)
{
FILE
*fp;
externinterrno;
char
*message;
if
(NULL==(fp=
fopen
(
"/dev/dsp"
,
"r+"
)))
{
printf
(
"errno=%d\n"
,
errno
);
message=
strerror
(
errno
);
printf
(
"Mesg:%s\n"
,message);
}
exit
(0);
}
|
輸出：
error=2
Mesg:No such file or direcory
例二：
// crt_perror.c
// compile with: /W1
/* This program attempts to open a file named
* NOSUCHF.ILE. Because this file probably doesn't exist,
* an error message is displayed. The same message is
* created using perror, strerror, and _strerror.
*/
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <io.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <share.h>
int main( void )
{
int fh;
if( _sopen_s( &fh, "NOSUCHF.ILE", _O_RDONLY, _SH_DENYNO, 0 ) != 0 )
{
/* Three ways to create error message: */
perror( "perror says open failed" );
printf( "strerror says open failed: %s\n",
strerror( errno ) ); // C4996
printf( _strerror( "_strerror says open failed" ) ); // C4996
// Note: strerror and _strerror are deprecated; consider
// using strerror_s and _strerror_s instead.
}
else
{
printf( "open succeeded on input file\n" );
_close( fh );
}
}
輸出：
perror says open failed: No such file or directory
strerror says open failed: No such file or directory
_strerror says open failed: No such file or directory
轉自 ： http://baike.baidu.com/link?url=pllZsYxUR2EJ26CRuWn_F8x7cUimLjEi6g_tPsEnENMv3L4zzXhwqtQ1u7ry8IrHbCh29BbgJTVACTPfawZ1J_
linux下錯誤的捕獲：errno和strerror的使用
常常在調用linux 系統api 的時候會出現一些錯誤，比方說使用open() write() creat()之類的函數有些時候會返回-1，也就是調用失敗，這個時候每每須要知道失敗的緣由。這個時候使用errno這個全局變量就至關有用了。 在程序代碼中包含 #include <errno.h>,而後每次程序調用失敗的時候，系統會自動用用錯誤代碼填充errno這個全局變量，這樣你只須要讀errno這個全局變量就能夠得到失敗緣由了。 例如： #include <stdio.h> #include <string.h> #include <errno.h> int main(void) { int fd; extern int errno; if((fd = open("/dev/dsp",O_WRONLY)) < 0) { printf("errno=%d\n",errno); } exit(0); } 若是dsp設備忙的話errno值將是16。 errno.h中定義的錯誤代碼值以下： 查 看錯誤代碼errno是調試程序的一個重要方法。當linuc C api函數發生異常時,通常會將errno變量(需include errno.h)賦一個整數值,不一樣的值表示不一樣的含義,能夠經過查看該值推測出錯的緣由。在實際編程中用這一招解決了很多本來看來莫名其妙的問題。比較 麻煩的是每次都要去linux源代碼裏面查找錯誤代碼的含義，如今把它貼出來，之後須要查時就來這裏看了。 如下來自linux 2.4.20-18的內核代碼中的/usr/include/asm/errno.h #ifndef _I386_ERRNO_H #define _I386_ERRNO_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 /* Arg 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 */ #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 NFS 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 */ #endif 同時也可使用strerror（）來本身翻譯 如： #include <stdio.h> #include <string.h> #include <errno.h> int main(void) { int fd; extern int errno; if((fd = open("/dev/dsp",O_WRONLY)) < 0) { printf("errno=%d\n",errno); char * mesg = strerror(errno); printf("Mesg:%s\n",mesg); } exit(0); } dsp設備忙的話將輸出以下： errno=16 Mesg:Device or resource busy