例如:
int fd;
if((fd = open(path, O_RDONLY)) == -1)
printf("error: %d %s %s\n", errno, strerror(errno), ERRNONAME(errno));
那么,ERRNONAME会返回一个名称,例如"EINVAL"、"EPERM"等。这种情况是否可能?
这些名称作为宏存在于Errno.h文件中。没有标准的调用来将错误编号转换为短代码。您可以构建自己的表格...
我最近写了errnoname
来实现此功能。
不幸的是,仍然没有标准API来实现它。(GNU的glibc有strerrorname_np
,但当前没有其他C库提供它,因此它甚至在所有Linux发行版上都不可用,更不用说其他地方了。)
我尝试保持它在所有系统上具有可移植性,同时覆盖该系统上所有的errno
名称。到目前为止,它已经包括了Linux、Darwin(macOS、iOS等)、BSD(FreeBSD、NetBSD、OpenBSD等)、几个闭源UNIX、Windows和一些其他系统。
唯一的“困难”部分是获取errno
名称和值的列表以进行查找,知道在目标系统上哪些errno
被定义,并详尽处理多个errno
名称可能映射到相同数字的所有情况。(例如,在某些系统上EWOULDBLOCK
等于EAGAIN
。)
所以在我的errnoname
库中,您不必处理任何这些问题。我将许多操作系统的errno
名称收集到一个列表中作为单独的步骤,然后从中生成实际的发布的C代码。该C代码对于每个名称都使用#ifdef
,因此它可以在任何系统上编译,而不管该系统具有哪些errno
名称和值。编译结果只是简单高效的代码,不需要调用任何程序或在库头文件中搜索errno
。
我还提供了两种选项:将其编译为数组查找或switch
,因为errno
值不能保证接近连续,但在许多系统上接近连续使得数组查找更好。(尽管良好的现代编译器可以自动注意到何时最好将switch转换为数组查找。)
无论如何,由于它是根据“零条款BSD许可”(0BSD)发布的,这是一种宽松许可证,或更准确地说是公共域等效许可证,因此您可以随意使用它。
以下是我的库中函数的旧复制粘贴,以便即使我的存储库链接失效,这个答案也有用,但请注意:
此处的复制仅涵盖截至2019年8月初我能找到的所有 errno
名称 - 自那时以来,我已经找到了许多其他名称。
我将继续更新库以包含我发现的 errno
名称,并随着系统添加它们、添加其他改进和添加重复保护而更新。但我不会(并且最后我检查过是不能)更新此答案的复制,因为答案的大小有限制。
#include <errno.h>
char const * errnoname(int errno_)
{
switch(errno_)
{
#ifdef E2BIG
case E2BIG: return "E2BIG";
#endif
#ifdef EACCES
case EACCES: return "EACCES";
#endif
#ifdef EADDRINUSE
case EADDRINUSE: return "EADDRINUSE";
#endif
#ifdef EADDRNOTAVAIL
case EADDRNOTAVAIL: return "EADDRNOTAVAIL";
#endif
#ifdef EADI
case EADI: return "EADI";
#endif
#ifdef EADV
case EADV: return "EADV";
#endif
#ifdef EAFNOSUPPORT
case EAFNOSUPPORT: return "EAFNOSUPPORT";
#endif
#ifdef EAGAIN
case EAGAIN: return "EAGAIN";
#endif
#ifdef EAIO
case EAIO: return "EAIO";
#endif
#ifdef EALIGN
case EALIGN: return "EALIGN";
#endif
#ifdef EALREADY
case EALREADY: return "EALREADY";
#endif
#ifdef EASYNC
case EASYNC: return "EASYNC";
#endif
#ifdef EAUTH
case EAUTH: return "EAUTH";
#endif
#ifdef EBADARCH
case EBADARCH: return "EBADARCH";
#endif
#ifdef EBADE
case EBADE: return "EBADE";
#endif
#ifdef EBADEXEC
case EBADEXEC: return "EBADEXEC";
#endif
#ifdef EBADF
case EBADF: return "EBADF";
#endif
#ifdef EBADFD
case EBADFD: return "EBADFD";
#endif
#ifdef EBADMACHO
case EBADMACHO: return "EBADMACHO";
#endif
#ifdef EBADMSG
case EBADMSG: return "EBADMSG";
#endif
#ifdef EBADR
case EBADR: return "EBADR";
#endif
#ifdef EBADRPC
case EBADRPC: return "EBADRPC";
#endif
#ifdef EBADRQC
case EBADRQC: return "EBADRQC";
#endif
#ifdef EBADSLT
case EBADSLT: return "EBADSLT";
#endif
#ifdef EBADVER
case EBADVER: return "EBADVER";
#endif
#ifdef EBFONT
case EBFONT: return "EBFONT";
#endif
#ifdef EBUSY
case EBUSY: return "EBUSY";
#endif
#ifdef ECANCELED
case ECANCELED: return "ECANCELED";
#endif
#if defined(ECANCELLED) && (!defined(ECANCELED) || ECANCELLED != ECANCELED)
case ECANCELLED: return "ECANCELLED";
#endif
#ifdef ECAPMODE
case ECAPMODE: return "ECAPMODE";
#endif
#ifdef ECHILD
case ECHILD: return "ECHILD";
#endif
#ifdef ECHRNG
case ECHRNG: return "ECHRNG";
#endif
#ifdef ECKPT
case ECKPT: return "ECKPT";
#endif
#ifdef ECLONEME
case ECLONEME: return "ECLONEME";
#endif
#ifdef ECOMM
case ECOMM: return "ECOMM";
#endif
#ifdef ECONFIG
case ECONFIG: return "ECONFIG";
#endif
#ifdef ECONNABORTED
case ECONNABORTED: return "ECONNABORTED";
#endif
#ifdef ECONNREFUSED
case ECONNREFUSED: return "ECONNREFUSED";
#endif
#ifdef ECONNRESET
case ECONNRESET: return "ECONNRESET";
#endif
#ifdef ECORRUPT
case ECORRUPT: return "ECORRUPT";
#endif
#ifdef ECVCERORR
case ECVCERORR: return "ECVCERORR";
#endif
#ifdef ECVPERORR
case ECVPERORR: return "ECVPERORR";
#endif
#ifdef EDEADLK
case EDEADLK: return "EDEADLK";
#endif
#if defined(EDEADLOCK) && (!defined(EDEADLK) || EDEADLOCK != EDEADLK)
case EDEADLOCK: return "EDEADLOCK";
#endif
#ifdef EDESTADDREQ
case EDESTADDREQ: return "EDESTADDREQ";
#endif
#ifdef EDESTADDRREQ
case EDESTADDRREQ: return "EDESTADDRREQ";
#endif
#ifdef EDEVERR
case EDEVERR: return "EDEVERR";
#endif
#ifdef EDIRIOCTL
case EDIRIOCTL: return "EDIRIOCTL";
#endif
#ifdef EDIRTY
case EDIRTY: return "EDIRTY";
#endif
#ifdef EDIST
case EDIST: return "EDIST";
#endif
#ifdef EDOM
case EDOM: return "EDOM";
#endif
#ifdef EDOOFUS
case EDOOFUS: return "EDOOFUS";
#endif
#ifdef EDOTDOT
case EDOTDOT: return "EDOTDOT";
#endif
#ifdef EDQUOT
case EDQUOT: return "EDQUOT";
#endif
#ifdef EDUPFD
case EDUPFD: return "EDUPFD";
#endif
#ifdef EDUPPKG
case EDUPPKG: return "EDUPPKG";
#endif
#ifdef EEXIST
case EEXIST: return "EEXIST";
#endif
#ifdef EFAIL
case EFAIL: return "EFAIL";
#endif
#ifdef EFAULT
case EFAULT: return "EFAULT";
#endif
#ifdef EFBIG
case EFBIG: return "EFBIG";
#endif
#ifdef EFORMAT
case EFORMAT: return "EFORMAT";
#endif
#ifdef EFSCORRUPTED
case EFSCORRUPTED: return "EFSCORRUPTED";
#endif
#ifdef EFTYPE
case EFTYPE: return "EFTYPE";
#endif
#ifdef EHOSTDOWN
case EHOSTDOWN: return "EHOSTDOWN";
#endif
#ifdef EHOSTUNREACH
case EHOSTUNREACH: return "EHOSTUNREACH";
#endif
#ifdef EHWPOISON
case EHWPOISON: return "EHWPOISON";
#endif
#ifdef EIDRM
case EIDRM: return "EIDRM";
#endif
#ifdef EILSEQ
case EILSEQ: return "EILSEQ";
#endif
#ifdef EINIT
case EINIT: return "EINIT";
#endif
#ifdef EINPROG
case EINPROG: return "EINPROG";
#endif
#ifdef EINPROGRESS
case EINPROGRESS: return "EINPROGRESS";
#endif
#ifdef EINTEGRITY
case EINTEGRITY: return "EINTEGRITY";
#endif
#ifdef EINTR
case EINTR: return "EINTR";
#endif
#ifdef EINVAL
case EINVAL: return "EINVAL";
#endif
#ifdef EIO
case EIO: return "EIO";
#endif
#ifdef EIPSEC
case EIPSEC: return "EIPSEC";
#endif
#ifdef EISCONN
case EISCONN: return "EISCONN";
#endif
#ifdef EISDIR
case EISDIR: return "EISDIR";
#endif
#ifdef EISNAM
case EISNAM: return "EISNAM";
#endif
#ifdef EJUSTRETURN
case EJUSTRETURN: return "EJUSTRETURN";
#endif
#ifdef EKEEPLOOKING
case EKEEPLOOKING: return "EKEEPLOOKING";
#endif
#ifdef EKEYEXPIRED
case EKEYEXPIRED: return "EKEYEXPIRED";
#endif
#ifdef EKEYREJECTED
case EKEYREJECTED: return "EKEYREJECTED";
#endif
#ifdef EKEYREVOKED
case EKEYREVOKED: return "EKEYREVOKED";
#endif
#ifdef EL2HLT
case EL2HLT: return "EL2HLT";
#endif
#ifdef EL2NSYNC
case EL2NSYNC: return "EL2NSYNC";
#endif
#ifdef EL3HLT
case EL3HLT: return "EL3HLT";
#endif
#ifdef EL3RST
case EL3RST: return "EL3RST";
#endif
#ifdef ELIBACC
case ELIBACC: return "ELIBACC";
#endif
#ifdef ELIBBAD
case ELIBBAD: return "ELIBBAD";
#endif
#ifdef ELIBEXEC
case ELIBEXEC: return "ELIBEXEC";
#endif
#ifdef ELIBMAX
case ELIBMAX: return "ELIBMAX";
#endif
#ifdef ELIBSCN
case ELIBSCN: return "ELIBSCN";
#endif
#ifdef ELNRNG
case ELNRNG: return "ELNRNG";
#endif
#ifdef ELOCKUNMAPPED
case ELOCKUNMAPPED: return "ELOCKUNMAPPED";
#endif
#ifdef ELOOP
case ELOOP: return "ELOOP";
#endif
#ifdef EMEDIA
case EMEDIA: return "EMEDIA";
#endif
#ifdef EMEDIUMTYPE
case EMEDIUMTYPE: return "EMEDIUMTYPE";
#endif
#ifdef EMFILE
case EMFILE: return "EMFILE";
#endif
#ifdef EMLINK
case EMLINK: return "EMLINK";
#endif
#ifdef EMOUNTEXIT
case EMOUNTEXIT: return "EMOUNTEXIT";
#endif
#ifdef EMOVEFD
case EMOVEFD: return "EMOVEFD";
#endif
#ifdef EMSGSIZE
case EMSGSIZE: return "EMSGSIZE";
#endif
#ifdef EMTIMERS
case EMTIMERS: return "EMTIMERS";
#endif
#ifdef EMULTIHOP
case EMULTIHOP: return "EMULTIHOP";
#endif
#ifdef ENAMETOOLONG
case ENAMETOOLONG: return "ENAMETOOLONG";
#endif
#ifdef ENAVAIL
case ENAVAIL: return "ENAVAIL";
#endif
#ifdef ENEEDAUTH
case ENEEDAUTH: return "ENEEDAUTH";
#endif
#ifdef ENETDOWN
case ENETDOWN: return "ENETDOWN";
#endif
#ifdef ENETRESET
case ENETRESET: return "ENETRESET";
#endif
#ifdef ENETUNREACH
case ENETUNREACH: return "ENETUNREACH";
#endif
#ifdef ENFILE
case ENFILE: return "ENFILE";
#endif
#ifdef ENFSREMOTE
case ENFSREMOTE: return "ENFSREMOTE";
#endif
#ifdef ENOANO
case ENOANO: return "ENOANO";
#endif
#ifdef ENOATTR
case ENOATTR: return "ENOATTR";
#endif
#ifdef ENOBUFS
case ENOBUFS: return "ENOBUFS";
#endif
#ifdef ENOCONNECT
case ENOCONNECT: return "ENOCONNECT";
#endif
#ifdef ENOCSI
case ENOCSI: return "ENOCSI";
#endif
#ifdef ENODATA
case ENODATA: return "ENODATA";
#endif
#ifdef ENODEV
case ENODEV: return "ENODEV";
#endif
#ifdef ENOENT
case ENOENT: return "ENOENT";
#endif
#ifdef ENOEXEC
case ENOEXEC: return "ENOEXEC";
#endif
#ifdef ENOIOCTL
case ENOIOCTL: return "ENOIOCTL";
#endif
#ifdef ENOKEY
case ENOKEY: return "ENOKEY";
#endif
#ifdef ENOLCK
case ENOLCK: return "ENOLCK";
#endif
#ifdef ENOLINK
case ENOLINK: return "ENOLINK";
#endif
#ifdef ENOLOAD
case ENOLOAD: return "ENOLOAD";
#endif
#ifdef ENOMATCH
case ENOMATCH: return "ENOMATCH";
#endif
#ifdef ENOMEDIUM
case ENOMEDIUM: return "ENOMEDIUM";
#endif
#ifdef ENOMEM
case ENOMEM: return "ENOMEM";
#endif
#ifdef ENOMSG
case ENOMSG: return "ENOMSG";
#endif
#ifdef ENONET
case ENONET: return "ENONET";
#endif
#ifdef ENOPKG
case ENOPKG: return "ENOPKG";
#endif
#ifdef ENOPOLICY
case ENOPOLICY: return "ENOPOLICY";
#endif
#ifdef ENOPROTOOPT
case ENOPROTOOPT: return "ENOPROTOOPT";
#endif
#ifdef ENOREG
case ENOREG: return "ENOREG";
#endif
#ifdef ENOSPC
case ENOSPC: return "ENOSPC";
#endif
#ifdef ENOSR
case ENOSR: return "ENOSR";
#endif
#ifdef ENOSTR
case ENOSTR: return "ENOSTR";
#endif
#ifdef ENOSYM
case ENOSYM: return "ENOSYM";
#endif
#ifdef ENOSYS
case ENOSYS: return "ENOSYS";
#endif
#ifdef ENOTACTIVE
case ENOTACTIVE: return "ENOTACTIVE";
#endif
#ifdef ENOTBLK
case ENOTBLK: return "ENOTBLK";
#endif
#ifdef ENOTCAPABLE
case ENOTCAPABLE: return "ENOTCAPABLE";
#endif
#ifdef ENOTCONN
case ENOTCONN: return "ENOTCONN";
#endif
#ifdef ENOTDIR
case ENOTDIR: return "ENOTDIR";
#endif
#ifdef ENOTEMPTY
case ENOTEMPTY: return "ENOTEMPTY";
#endif
#ifdef ENOTNAM
case ENOTNAM: return "ENOTNAM";
#endif
#ifdef ENOTREADY
case ENOTREADY: return "ENOTREADY";
#endif
#ifdef ENOTRECOVERABLE
case ENOTRECOVERABLE: return "ENOTRECOVERABLE";
#endif
#ifdef ENOTRUST
case ENOTRUST: return "ENOTRUST";
#endif
#ifdef ENOTSOCK
case ENOTSOCK: return "ENOTSOCK";
#endif
#ifdef ENOTSUP
case ENOTSUP: return "ENOTSUP";
#endif
#ifdef ENOTTY
case ENOTTY: return "ENOTTY";
#endif
#ifdef ENOTUNIQ
case ENOTUNIQ: return "ENOTUNIQ";
#endif
#ifdef ENOUNLD
case ENOUNLD: return "ENOUNLD";
#endif
#ifdef ENOUNREG
case ENOUNREG: return "ENOUNREG";
#endif
#ifdef ENXIO
case ENXIO: return "ENXIO";
#endif
#ifdef EOPCOMPLETE
case EOPCOMPLETE: return "EOPCOMPLETE";
#endif
#if defined(EOPNOTSUPP) && (!defined(ENOTSUP) || EOPNOTSUPP != ENOTSUP)
case EOPNOTSUPP: return "EOPNOTSUPP";
#endif
#ifdef EOVERFLOW
case EOVERFLOW: return "EOVERFLOW";
#endif
#ifdef EOWNERDEAD
case EOWNERDEAD: return "EOWNERDEAD";
#endif
#ifdef EPASSTHROUGH
case EPASSTHROUGH: return "EPASSTHROUGH";
#endif
#ifdef EPATHREMOTE
case EPATHREMOTE: return "EPATHREMOTE";
#endif
#ifdef EPERM
case EPERM: return "EPERM";
#endif
#ifdef EPFNOSUPPORT
case EPFNOSUPPORT: return "EPFNOSUPPORT";
#endif
#ifdef EPIPE
case EPIPE: return "EPIPE";
#endif
#ifdef EPOWERF
case EPOWERF: return "EPOWERF";
#endif
#ifdef EPROCLIM
case EPROCLIM: return "EPROCLIM";
#endif
#ifdef EPROCUNAVAIL
case EPROCUNAVAIL: return "EPROCUNAVAIL";
#endif
#ifdef EPROGMISMATCH
case EPROGMISMATCH: return "EPROGMISMATCH";
#endif
#ifdef EPROGUNAVAIL
case EPROGUNAVAIL: return "EPROGUNAVAIL";
#endif
#ifdef EPROTO
case EPROTO: return "EPROTO";
#endif
#ifdef EPROTONOSUPPORT
case EPROTONOSUPPORT: return "EPROTONOSUPPORT";
#endif
#ifdef EPROTOTYPE
case EPROTOTYPE: return "EPROTOTYPE";
#endif
#ifdef EPWROFF
case EPWROFF: return "EPWROFF";
#endif
#ifdef EQFULL
case EQFULL: return "EQFULL";
#endif
#ifdef EQSUSPENDED
case EQSUSPENDED: return "EQSUSPENDED";
#endif
#ifdef ERANGE
case ERANGE: return "ERANGE";
#endif
#ifdef ERECYCLE
case ERECYCLE: return "ERECYCLE";
#endif
#ifdef EREDRIVEOPEN
case EREDRIVEOPEN: return "EREDRIVEOPEN";
#endif
#ifdef EREFUSED
case EREFUSED: return "EREFUSED";
#endif
#ifdef ERELOC
case ERELOC: return "ERELOC";
#endif
#ifdef ERELOCATED
case ERELOCATED: return "ERELOCATED";
#endif
#ifdef ERELOOKUP
case ERELOOKUP: return "ERELOOKUP";
#endif
#ifdef EREMCHG
case EREMCHG: return "EREMCHG";
#endif
#ifdef EREMDEV
case EREMDEV: return "EREMDEV";
#endif
#ifdef EREMOTE
case EREMOTE: return "EREMOTE";
#endif
#ifdef EREMOTEIO
case EREMOTEIO: return "EREMOTEIO";
#endif
#ifdef EREMOTERELEASE
case EREMOTERELEASE: return "EREMOTERELEASE";
#endif
#ifdef ERESTART
case ERESTART: return "ERESTART";
#endif
#ifdef ERFKILL
case ERFKILL: return "ERFKILL";
#endif
#ifdef EROFS
case EROFS: return "EROFS";
#endif
#ifdef ERPCMISMATCH
case ERPCMISMATCH: return "ERPCMISMATCH";
#endif
#ifdef ESAD
case ESAD: return "ESAD";
#endif
#ifdef ESHLIBVERS
case ESHLIBVERS: return "ESHLIBVERS";
#endif
#ifdef ESHUTDOWN
case ESHUTDOWN: return "ESHUTDOWN";
#endif
#ifdef ESOCKTNOSUPPORT
case ESOCKTNOSUPPORT: return "ESOCKTNOSUPPORT";
#endif
#ifdef ESOFT
case ESOFT: return "ESOFT";
#endif
#ifdef ESPIPE
case ESPIPE: return "ESPIPE";
#endif
#ifdef ESRCH
case ESRCH: return "ESRCH";
#endif
#ifdef ESRMNT
case ESRMNT: return "ESRMNT";
#endif
#ifdef ESTALE
case ESTALE: return "ESTALE";
#endif
#ifdef ESTART
case ESTART: return "ESTART";
#endif
#ifdef ESTRPIPE
case ESTRPIPE: return "ESTRPIPE";
#endif
#ifdef ESYSERROR
case ESYSERROR: return "ESYSERROR";
#endif
#ifdef ETIME
case ETIME: return "ETIME";
#endif
#ifdef ETIMEDOUT
case ETIMEDOUT: return "ETIMEDOUT";
#endif
#ifdef ETOOMANYREFS
case ETOOMANYREFS: return "ETOOMANYREFS";
#endif
#ifdef ETXTBSY
case ETXTBSY: return "ETXTBSY";
#endif
#ifdef EUCLEAN
case EUCLEAN: return "EUCLEAN";
#endif
#ifdef EUNATCH
case EUNATCH: return "EUNATCH";
#endif
#ifdef EUSERS
case EUSERS: return "EUSERS";
#endif
#ifdef EVERSION
case EVERSION: return "EVERSION";
#endif
#if defined(EWOULDBLOCK) && (!defined(EAGAIN) || EWOULDBLOCK != EAGAIN)
case EWOULDBLOCK: return "EWOULDBLOCK";
#endif
#ifdef EWRONGFS
case EWRONGFS: return "EWRONGFS";
#endif
#ifdef EWRPROTECT
case EWRPROTECT: return "EWRPROTECT";
#endif
#ifdef EXDEV
case EXDEV: return "EXDEV";
#endif
#ifdef EXFULL
case EXFULL: return "EXFULL";
#endif
}
return 0;
}
strerror
libc 函数。#include <string.h>
...
printf("err = %s \n", strerror(errno));
perror
和strerror
获取的字符串将本地化为该语言环境中的errno
名称。我认为,随着技术的使用增长,计算机之间的交流比人类之间的交流更多,工具和脚本可以从使序列化和解析更简单和优化的“语言环境”中受益良多。因此,虽然这个答案实际上不是提问者想要的,但在某些方面,这是“正确”的答案-APIs如perror
和strerror
是表示“将errno
表示为字符串”的标准方式。 - mtraceur