函數說明
perror ( )用來將上一個函數發生錯誤的原因輸出到標準錯誤(stderr),參數s 所指的字符串會先打印出,後面再加上錯誤原因 字符串。此錯誤原因依照全局變量 errno 的值來決定要輸出的字符串。
2. char *strerror(int errno)
將錯誤代碼轉換爲字符串錯誤信息。
errno 在 <errno.h> 中定義。
錯誤 Exx 的宏定義在 /usr/include/asm-generic 文件夾下面的 errno-base.h 和 errno.h，分別定義了 1-34 、35-132 的錯誤定義。
#defineEPERM
1/* Operation not permitted */
#define ENOENT2
/* 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 ECHILD10
/* No child processes */
#define EAGAIN11
/* Try again */
#define ENOMEM12
/* Out of memory */
#define EACCES13
/* Permission denied */
#define EFAULT14
/* Bad address */
#define ENOTBLK15
/* Block device required */
#define EBUSY
16 /* Device or resource busy */
#define EEXIST17
/* File exists */
#define EXDEV
18 /* Cross-device link */
#define ENODEV19
/* No such device */
#define ENOTDIR20
/* Not a directory */
#define EISDIR21
/* Is a directory */
#define EINVAL22
/* Invalid argument */
#define ENFILE23
/* File table overflow */
#define EMFILE24
/* Too many open files */
#define ENOTTY25
/* Not a typewriter */
#define ETXTBSY26
/* Text file busy */
#define EFBIG
27 /* File too large */
#define ENOSPC28
/* No space left on device */
#define ESPIPE29
/* Illegal seek */
#define EROFS
30 /* Read-only file system */
#define EMLINK31
/* Too many links */
#define EPIPE
32 /* Broken pipe */
#define EDOM
33 /* Math argument out of domain of func */
#define ERANGE34
/* Math result not representable */
#defineEDEADLK
35/* Resource deadlock would occur */
#define ENAMETOOLONG36
/* File name too long */
#define ENOLCK37
/* No record locks available */
#define ENOSYS38
/* Function not implemented */
#define ENOTEMPTY39
/* Directory not empty */
#define ELOOP
40 /* Too many symbolic links encountered */
#define EWOULDBLOCKEAGAIN
/* Operation would block */
#define ENOMSG42
/* No message of desired type */
#define EIDRM
43 /* Identifier removed */
#define ECHRNG44
/* Channel number out of range */
#define EL2NSYNC45
/* Level 2 not synchronized */
#define EL3HLT46
/* Level 3 halted */
#define EL3RST47
/* Level 3 reset */
#define ELNRNG48
/* Link number out of range */
#define EUNATCH49
/* Protocol driver not attached */
#define ENOCSI50
/* No CSI structure available */
#define EL2HLT51
/* Level 2 halted */
#define EBADE
52 /* Invalid exchange */
#define EBADR
53 /* Invalid request descriptor */
#define EXFULL54
/* Exchange full */
#define ENOANO55
/* No anode */
#define EBADRQC56
/* Invalid request code */
#define EBADSLT57
/* Invalid slot */
#define EDEADLOCKEDEADLK
#define EBFONT59
/* Bad font file format */
#define ENOSTR60
/* Device not a stream */
#define ENODATA61
/* No data available */
#define ETIME
62 /* Timer expired */
#define ENOSR
63 /* Out of streams resources */
#define ENONET64
/* Machine is not on the network */
#define ENOPKG65
/* Package not installed */
#define EREMOTE66
/* Object is remote */
#define ENOLINK67
/* Link has been severed */
#define EADV
68 /* Advertise error */
#define ESRMNT69
/* Srmount error */
#define ECOMM
70 /* Communication error on send */
#define EPROTO71
/* Protocol error */
#define EMULTIHOP72
/* Multihop attempted */
#define EDOTDOT73
/* RFS specific error */
#define EBADMSG74
/* Not a data message */
#define EOVERFLOW75
/* Value too large for defined data type */
#define ENOTUNIQ76
/* Name not unique on network */
#define EBADFD77
/* File descriptor in bad state */
#define EREMCHG78
/* Remote address changed */
#define ELIBACC79
/* Can not access a needed shared library */
#define ELIBBAD80
/* Accessing a corrupted shared library */
#define ELIBSCN81
/* .lib section in a.out corrupted */
#define ELIBMAX82
/* Attempting to link in too many shared libraries */
#define ELIBEXEC83
/* Cannot exec a shared library directly */
#define EILSEQ84
/* Illegal byte sequence */
#define ERESTART85
/* Interrupted system call should be restarted */
#define ESTRPIPE86
/* Streams pipe error */
#define EUSERS87
/* Too many users */
#define ENOTSOCK88
/* Socket operation on non-socket */
#define EDESTADDRREQ89
/* Destination address required */
#define EMSGSIZE90
/* Message too long */
#define EPROTOTYPE91
/* Protocol wrong type for socket */
#define ENOPROTOOPT92
/* Protocol not available */
#define EPROTONOSUPPORT93
/* Protocol not supported */
#define ESOCKTNOSUPPORT94
/* Socket type not supported */
#define EOPNOTSUPP95
/* Operation not supported on transport endpoint */
#define EPFNOSUPPORT96
/* Protocol family not supported */
#define EAFNOSUPPORT97
/* Address family not supported by protocol */
#define EADDRINUSE98
/* Address already in use */
#define EADDRNOTAVAIL99
/* Cannot assign requested address */
#define ENETDOWN100
/* Network is down */
#define ENETUNREACH101
/* Network is unreachable */
#define ENETRESET102
/* Network dropped connection because of reset */
#define ECONNABORTED103
/* Software caused connection abort */
#define ECONNRESET104
/* Connection reset by peer */
#define ENOBUFS105
/* No buffer space available */
#define EISCONN106
/* Transport endpoint is already connected */
#define ENOTCONN107
/* Transport endpoint is not connected */
#define ESHUTDOWN108
/* Cannot send after transport endpoint shutdown */
#define ETOOMANYREFS109
/* Too many references: cannot splice */
#define ETIMEDOUT110
/* Connection timed out */
#define ECONNREFUSED111
/* Connection refused */
#define EHOSTDOWN112
/* Host is down */
#define EHOSTUNREACH113
/* No route to host */
#define EALREADY114
/* Operation already in progress */
#define EINPROGRESS115
/* Operation now in progress */
#define ESTALE116
/* Stale NFS file handle */
#define EUCLEAN117
/* Structure needs cleaning */
#define ENOTNAM118
/* Not a XENIX named type file */
#define ENAVAIL119
/* No XENIX semaphores available */
#define EISNAM120
/* Is a named type file */
#define EREMOTEIO121
/* Remote I/O error */
#define EDQUOT122
/* Quota exceeded */
#define ENOMEDIUM123
/* No medium found */
#define EMEDIUMTYPE124
/* Wrong medium type */
#define ECANCELED125
/* Operation Canceled */
#define ENOKEY126
/* Required key not available */
#define EKEYEXPIRED127
/* Key has expired */
#define EKEYREVOKED128
/* Key has been revoked */
#define EKEYREJECTED129
/* Key was rejected by service */
/* for robust mutexes */
#define EOWNERDEAD130
/* Owner died */
#define ENOTRECOVERABLE131
/* State not recoverable */
#define ERFKILL 132/* Operation not possible due to RF-kill */
#define EHWPOISON 133/* Memory page has hardware error */