系统运维工程师和系统开发工程师在日常工作中，经常会遇到此类问题“当你进行了一些不当操作，系统会给你错误提示”，这些错误提示在操作系统中都是错误编码的，每一个提示对应一个错误编码，错误编码供程序代码中方便调用，接下来我们会打印出linux操作系统的错误编码及提示，如下：
一、系统环境
系统版本：

内核版本：

二、程序代码
代码如下：

三、编译运行
结果如下：
[root@CentOS6 erro_num]# gcc error_num.c        
[root@centos6 erro_num]# ./a.out         
0:Success
1:Operation not permitted
2:No such file or directory
3:No such process
4:Interrupted system call
5:Input/output error
6:No such device or address
7:Argument list too long
8:Exec format error
9:Bad file descriptor
10:No child processes
11:Resource temporarily unavailable
12:Cannot allocate memory
13ermission denied
14:Bad address
15:Block device required
16evice or resource busy
17:File exists
18:Invalid cross-device link
19:No such device
20:Not a directory
21:Is a directory
22:Invalid argument
23:Too many open files in system
24:Too many open files
25:Inappropriate ioctl for device
26:Text file busy
27:File too large
28:No space left on device
29:Illegal seek
30:Read-only file system
31:Too many links
32:Broken pipe
33:Numerical argument out of domain
34:Numerical result out of range
35:Resource deadlock avoided
36:File name too long
37:No locks available
38:Function not implemented
39irectory not empty
40:Too many levels of symbolic links
41:Unknown error 41
42:No message of desired type
43:Identifier removed
44:Channel number out of range
45evel 2 not synchronized
46evel 3 halted
47evel 3 reset
48ink number out of range
49rotocol driver not attached
50:No CSI structure available
51evel 2 halted
52:Invalid exchange
53:Invalid request descriptor
54:Exchange full
55:No anode
56:Invalid request code
57:Invalid slot
58:Unknown error 58
59:Bad font file format
60evice not a stream
61:No data available
62:Timer expired
63:Out of streams resources
64:Machine is not on the network
65ackage not installed
66:Object is remote
67ink has been severed
68:Advertise error
69:Srmount error
70:Communication error on send
71rotocol error
72:Multihop attempted
73:RFS specific error
74:Bad message
75:Value too large for defined data type
76:Name not unique on network
77:File descriptor in bad state
78:Remote address changed
79:Can not access a needed shared library
80:Accessing a corrupted shared library
81:.lib section in a.out corrupted
82:Attempting to link in too many shared libraries
83:Cannot exec a shared library directly
84:Invalid or incomplete multibyte or wide character
85:Interrupted system call should be restarted
86:Streams pipe error
87:Too many users
88:Socket operation on non-socket
89estination address required
90:Message too long
91rotocol wrong type for socket
92rotocol not available
93rotocol not supported
94:Socket type not supported
95:Operation not supported
96rotocol family not supported
97:Address family not supported by protocol
98:Address already in use
99:Cannot assign requested address
100:Network is down
101:Network is unreachable
102:Network dropped connection on reset
103:Software caused connection abort
104:Connection reset by peer
105:No buffer space available
106:Transport endpoint is already connected
107:Transport endpoint is not connected
108:Cannot send after transport endpoint shutdown
109:Too many references: cannot splice
110:Connection timed out
111:Connection refused
112:Host is down
113:No route to host
114:Operation already in progress
115:Operation now in progress
116:Stale NFS file handle
117:Structure needs cleaning
118:Not a XENIX named type file
119:No XENIX semaphores available
120:Is a named type file
121:Remote I/O error
122isk quota exceeded
123:No medium found
124:Wrong medium type
125:Operation canceled
126:Required key not available
127:Key has expired
128:Key has been revoked
129:Key was rejected by service
130:Owner died
131:State not recoverable
   如果你看过nginx-1.0.10源码，里面有一个类似的错误编码预定义 135个，在objs/ngx_auto_config.h 中，#define NGX_SYS_NERR135，事实证明，这种思想是非常可取的，我们自己写软件的时候，不妨尝试一下？