1 void perror( const char *string );//Print an error message.<stdio.h> or <stdlib.h>
 2 //msdn 示例代码
 3 /* PERROR.C: This program attempts to open a file named
 4  * NOSUCHF.ILE. Because this file probably doesn't exist,
 5  * an error message is displayed. The same message is
 6  * created using perror, strerror, and _strerror.
 7  */
 8
 9 #include <fcntl.h>
10 #include <sys/types.h>
11 #include <sys/stat.h>
12 #include <io.h>
13 #include <stdlib.h>
14 #include <stdio.h>
15 #include <string.h>
16
17 void main( void )
18 {
19    int  fh;
20
21    if( (fh = _open( "NOSUCHF.ILE", _O_RDONLY )) == -1 )
22    {
23       /* Three ways to create error message: */
24       perror( "perror says open failed" );
25       printf( "strerror says open failed: %s\n", strerror( errno ) );
26       printf( _strerror( "_strerror says open failed" ) );
27    }
28    else
29    {
30       printf( "open succeeded on input file\n" );
31       _close( fh );
32    }
33 }
34
35
36 /*Output
37
38 perror says open failed: No such file or directory
39
40 strerror says open failed: No such file or directory
41 _strerror says open failed: No such file or directory*/

/*strerror, _strerror
Get a system error message (strerror) or prints a user-supplied error message (_strerror).include "string.h"
strerror and _strerror return a pointer to the error-message string. Subsequent calls to strerror or _strerror can overwrite the string.*/
char *strerror( int errnum );
char *_strerror( const char *strErrMsg );

 1 /*GetLastError
 2 This function returns the calling thread’s last-error code value. A remote application interface (RAPI) version of this function exists, and it is named CeGetLastError. */
 3
 4 DWORD GetLastError( void );
 5
 6 /*FormatMessage
 7 This function formats a message string. */
 8
 9 DWORD FormatMessage (
10 DWORD dwFlags,
11 LPCVOID lpSource,
12 DWORD dwMessageId,
13 DWORD dwLanguageId,
14 LPTSTR lpBuffer,
15 DWORD nSize,
16 va_list *Arguments);
17
18
19 //示例用法
20 LPVOID lpMsgBuf;
21 FormatMessage(
22     FORMAT_MESSAGE_ALLOCATE_BUFFER |
23     FORMAT_MESSAGE_FROM_SYSTEM |
24     FORMAT_MESSAGE_IGNORE_INSERTS,
25     NULL,
26     GetLastError(),
27     0, // Default language
28     (LPTSTR) &lpMsgBuf,
29     0,
30     NULL
31 );
32 // Process any inserts in lpMsgBuf.
33 // ...
34 // Display the string.
35 MessageBox( NULL, (LPCTSTR)lpMsgBuf, "Error", MB_OK | MB_ICONINFORMATION );
36 // Free the buffer.
37 LocalFree( lpMsgBuf );