c - strerror 描述字符串

Question

C 函数strerror 返回错误描述字符串，详见here .示例字符串

No such file or directory

问题是这些字符串在哪里定义的？我查看了我的头文件，但没有看到任何东西。

Answer 1

包含错误消息的头文件名为 errmsg.h

00012 const char *const sys_errlist[] = {
00013         "Operation succeeded",        /* 0 */
00014         "Invalid argument",           /* EINVAL */
00015         "Bad memory address",         /* EFAULT */
00016         "String too long",            /* ENAMETOOLONG */
00017         "Out of memory",              /* ENOMEM */
00018         "Input/output error",         /* EIO */
00019         "No such file or directory",  /* ENOENT */
00020         "Not a directory",            /* ENOTDIR */
00021         "Is a directory",             /* EISDIR */
00022         "File or object exists",      /* EEXIST */
00023         "Cross-device link",          /* EXDEV */
00024         "Try again later",            /* EAGAIN */
00025         "Illegal seek",               /* ESPIPE */
00026         "Unimplemented feature",      /* EUNIMP */
00027         "Device not available",       /* ENXIO */
00028         "No such device",             /* ENODEV */
00029         "Device or resource busy",    /* EBUSY */
00030         "Invalid/inappropriate ioctl",/* EIOCTL (ENOTTY in Unix) */
00031         "Directory not empty",        /* ENOTEMPTY */
00032         "Result too large",           /* ERANGE */
00033         "No space left on device",    /* ENOSPC */
00034         "Too many open files",        /* EMFILE */
00035         "Too many open files in system",/* ENFILE */
00036         "No such system call",        /* ENOSYS */
00037         "File is not executable",     /* ENOEXEC */
00038         "Argument list too long",     /* E2BIG */
00039         "Bad file number",            /* EBADF */
00040 };

如您所见，它取决于 libc 实现。但总体思路是相同的:一些数组包含从错误号到最大长度为 1024 字节的字符串的映射。

其他实现:

• http://emmanuel.varoquaux.free.fr/xos/viewfile.php?file=xos/usr/lib/libc/sys_errlist.c

• http://cristi.indefero.net/p/uClibc-cristi/source/tree/07439d8df31d7fefe82ff127a1690193a34e9060/libc/string/sys_errlist.c

• http://fossies.org/dox/glibc-2.16.0/stdio-common_2errlist_8c_source.html