open()打开文件失败错误码：
获取错误信息实例：
HANDLE hFile = 0; hFile = open(“c: est.txt”, O_RDWR, S_IRWXU|S_IRWXG|S_IRWXO); if (-1 == hFile) { printf("Error %d: Failed to open file ", errno); if (errno == EEXIST ) { printf("EEXIST 参数pathname 所指的文件已存在, 却使用了O_CREAT 和O_EXCL 旗标. "); }else if(errno == EACCES) { printf("EACCESS 参数pathname 所指的文件不符合所要求测试的权限. "); }else if(errno == EROFS) { printf("EROFS 欲测试写入权限的文件存在于只读文件系统内. "); }else ...... }
注：使用errno 需要加上头文件：
#include <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 /* Input/output error */ #define ENXIO 6 /* Device not configured */ #define E2BIG 7 /* Argument list too long */ #define ENOEXEC 8 /* Exec format error */ #define EBADF 9 /* Bad file descriptor */ #define ECHILD 10 /* No child processes */ #define EDEADLK 11 /* Resource deadlock avoided */ /* 11 was EAGAIN */ #define ENOMEM 12 /* Cannot allocate memory */ #define EACCES 13 /* Permission denied */ #define EFAULT 14 /* Bad address */ #if __DARWIN_C_LEVEL >= __DARWIN_C_FULL #define ENOTBLK 15 /* Block device required */ #endif #define EBUSY 16 /* Device / Resource busy */ #define EEXIST 17 /* File exists */ #define EXDEV 18 /* Cross-device link */ #define ENODEV 19 /* Operation not supported by device */ #define ENOTDIR 20 /* Not a directory */ #define EISDIR 21 /* Is a directory */ #define EINVAL 22 /* Invalid argument */ #define ENFILE 23 /* Too many open files in system */ #define EMFILE 24 /* Too many open files */ #define ENOTTY 25 /* Inappropriate ioctl for device */ #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 */ /* math software */ #define EDOM 33 /* Numerical argument out of domain */ #define ERANGE 34 /* Result too large */ /* non-blocking and interrupt i/o */ #define EAGAIN 35 /* Resource temporarily unavailable */ #define EWOULDBLOCK EAGAIN /* Operation would block */ #define EINPROGRESS 36 /* Operation now in progress */ #define EALREADY 37 /* Operation already in progress */ /* ipc/network software -- argument errors */ #define ENOTSOCK 38 /* Socket operation on non-socket */ #define EDESTADDRREQ 39 /* Destination address required */ #define EMSGSIZE 40 /* Message too long */ #define EPROTOTYPE 41 /* Protocol wrong type for socket */ #define ENOPROTOOPT 42 /* Protocol not available */ #define EPROTONOSUPPORT 43 /* Protocol not supported */ #if __DARWIN_C_LEVEL >= __DARWIN_C_FULL #define ESOCKTNOSUPPORT 44 /* Socket type not supported */ #endif #define ENOTSUP 45 /* Operation not supported */
#define EPFNOSUPPORT 46 /* Protocol family not supported */ #endif #define EAFNOSUPPORT 47 /* Address family not supported by protocol family */ #define EADDRINUSE 48 /* Address already in use */ #define EADDRNOTAVAIL 49 /* Can't assign requested address */ /* ipc/network software -- operational errors */ #define ENETDOWN 50 /* Network is down */ #define ENETUNREACH 51 /* Network is unreachable */ #define ENETRESET 52 /* Network dropped connection on reset */ #define ECONNABORTED 53 /* Software caused connection abort */ #define ECONNRESET 54 /* Connection reset by peer */ #define ENOBUFS 55 /* No buffer space available */ #define EISCONN 56 /* Socket is already connected */ #define ENOTCONN 57 /* Socket is not connected */ #if __DARWIN_C_LEVEL >= __DARWIN_C_FULL #define ESHUTDOWN 58 /* Can't send after socket shutdown */ #define ETOOMANYREFS 59 /* Too many references: can't splice */ #endif #define ETIMEDOUT 60 /* Operation timed out */ #define ECONNREFUSED 61 /* Connection refused */ #define ELOOP 62 /* Too many levels of symbolic links */ #define ENAMETOOLONG 63 /* File name too long */ /* should be rearranged */ #if __DARWIN_C_LEVEL >= __DARWIN_C_FULL #define EHOSTDOWN 64 /* Host is down */ #endif #define EHOSTUNREACH 65 /* No route to host */ #define ENOTEMPTY 66 /* Directory not empty */ /* quotas & mush */ #if __DARWIN_C_LEVEL >= __DARWIN_C_FULL #define EPROCLIM 67 /* Too many processes */ #define EUSERS 68 /* Too many users */ #endif #define EDQUOT 69 /* Disc quota exceeded */ /* Network File System */ #define ESTALE 70 /* Stale NFS file handle */ #if __DARWIN_C_LEVEL >= __DARWIN_C_FULL #define EREMOTE 71 /* Too many levels of remote in path */ #define EBADRPC 72 /* RPC struct is bad */ #define ERPCMISMATCH 73 /* RPC version wrong */ #define EPROGUNAVAIL 74 /* RPC prog. not avail */ #define EPROGMISMATCH 75 /* Program version wrong */ #define EPROCUNAVAIL 76 /* Bad procedure for program */ #endif #define ENOLCK 77 /* No locks available */ #define ENOSYS 78 /* Function not implemented */ #if __DARWIN_C_LEVEL >= __DARWIN_C_FULL #define EFTYPE 79 /* Inappropriate file type or format */ #define EAUTH 80 /* Authentication error */ #define ENEEDAUTH 81 /* Need authenticator */ /* Intelligent device errors */ #define EPWROFF 82 /* Device power is off */ #define EDEVERR 83 /* Device error, e.g. paper out */ #endif #define EOVERFLOW 84 /* Value too large to be stored in data type */ /* Program loading errors */ #if __DARWIN_C_LEVEL >= __DARWIN_C_FULL #define EBADEXEC 85 /* Bad executable */ #define EBADARCH 86 /* Bad CPU type in executable */ #define ESHLIBVERS 87 /* Shared library version mismatch */ #define EBADMACHO 88 /* Malformed Macho file */ #endif #define ECANCELED 89 /* Operation canceled */ #define EIDRM 90 /* Identifier removed */ #define ENOMSG 91 /* No message of desired type */ #define EILSEQ 92 /* Illegal byte sequence */ #if __DARWIN_C_LEVEL >= __DARWIN_C_FULL #define ENOATTR 93 /* Attribute not found */ #endif #define EBADMSG 94 /* Bad message */ #define EMULTIHOP 95 /* Reserved */ #define ENODATA 96 /* No message available on STREAM */ #define ENOLINK 97 /* Reserved */ #define ENOSR 98 /* No STREAM resources */ #define ENOSTR 99 /* Not a STREAM */ #define EPROTO 100 /* Protocol error */ #define ETIME 101 /* STREAM ioctl timeout */ #if __DARWIN_UNIX03 || defined(KERNEL) /* This value is only discrete when compiling __DARWIN_UNIX03, or KERNEL */ #define EOPNOTSUPP 102 /* Operation not supported on socket */ #endif /* __DARWIN_UNIX03 || KERNEL */ #define ENOPOLICY 103 /* No such policy registered */ #if __DARWIN_C_LEVEL >= 200809L #define ENOTRECOVERABLE 104 /* State not recoverable */ #define EOWNERDEAD 105 /* Previous owner died */ #endif #if __DARWIN_C_LEVEL >= __DARWIN_C_FULL #define EQFULL 106 /* Interface output queue is full */ #define ELAST 106 /* Must be equal largest errno */