Greg Hartman | 76d05dc | 2016-11-23 15:51:27 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * strerror.c |
| 3 | */ |
| 4 | |
| 5 | #include <string.h> |
| 6 | |
| 7 | char *strerror(int errnum) |
| 8 | { |
| 9 | static char message[32] = "error "; /* enough for error 2^63-1 */ |
| 10 | char numbuf[32]; |
| 11 | char *p; |
| 12 | unsigned int e = (unsigned int)errnum; |
| 13 | |
| 14 | extern const int sys_nerr; |
| 15 | extern const char *const sys_errlist[]; |
| 16 | |
| 17 | if (e < (unsigned int)sys_nerr && sys_errlist[e]) |
| 18 | return (char *)sys_errlist[e]; |
| 19 | |
| 20 | p = numbuf + sizeof numbuf; |
| 21 | *--p = '\0'; |
| 22 | |
| 23 | do { |
| 24 | *--p = (e % 10) + '0'; |
| 25 | e /= 10; |
| 26 | } while (e); |
| 27 | |
| 28 | memcpy(message + 6, p, (numbuf + sizeof numbuf) - p); |
| 29 | |
| 30 | return message; |
| 31 | } |