Error in iterative directory listing using C++ - c++

Question

I've come across this code for directory listing on Windows using C++,and I've understood that you can search a directory with these APIs: FindFirstFileEx, FindNextFile and CloseFind. You'll need to #include , that'll get you access to the Windows API.
I'm not able to understand how this code works, as a result not able to make out the compilation error.
#include <windows.h>
#include <tchar.h>
#include <stdio.h>
#include <strcat.h>
#pragma comment(lib, "User32.lib")
void DisplayErrorBox(LPTSTR lpszFunction);
int _tmain(int argc, TCHAR *argv[])
{
WIN32_FIND_DATA ffd;
LARGE_INTEGER filesize;
TCHAR szDir[MAX_PATH];
size_t length_of_arg;
HANDLE hFind = INVALID_HANDLE_VALUE;
DWORD dwError=0;
// If the directory is not specified as a command-line argument,
// print usage.
if(argc != 2)
{
_tprintf(TEXT("\nUsage: %s <directory name>\n"), argv[0]);
return (-1);
}
// Check that the input path plus 3 is not longer than MAX_PATH.
// Three characters are for the "\*" plus NULL appended below.
StringCchLength(argv[1], MAX_PATH, &length_of_arg);
if (length_of_arg > (MAX_PATH - 3))
{
_tprintf(TEXT("\nDirectory path is too long.\n"));
return (-1);
}
_tprintf(TEXT("\nTarget directory is %s\n\n"), argv[1]);
// Prepare string for use with FindFile functions. First, copy the
// string to a buffer, then append '\*' to the directory name.
StringCchCopy(szDir, MAX_PATH, argv[1]);
StringCchCat(szDir, MAX_PATH, TEXT("\\*"));
// Find the first file in the directory.
hFind = FindFirstFile(szDir, &ffd);
if (INVALID_HANDLE_VALUE == hFind)
{
DisplayErrorBox(TEXT("FindFirstFile"));
return dwError;
}
// List all the files in the directory with some info about them.
do
{
if (ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
{
_tprintf(TEXT(" %s <DIR>\n"), ffd.cFileName);
}
else
{
filesize.LowPart = ffd.nFileSizeLow;
filesize.HighPart = ffd.nFileSizeHigh;
_tprintf(TEXT(" %s %ld bytes\n"), ffd.cFileName, filesize.QuadPart);
}
}
while (FindNextFile(hFind, &ffd) != 0);
dwError = GetLastError();
if (dwError != ERROR_NO_MORE_FILES)
{
DisplayErrorBox(TEXT("FindFirstFile"));
}
FindClose(hFind);
return dwError;
}
void DisplayErrorBox(LPTSTR lpszFunction)
{
// Retrieve the system error message for the last-error code
LPVOID lpMsgBuf;
LPVOID lpDisplayBuf;
DWORD dw = GetLastError();
FormatMessage(
FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
dw,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) &lpMsgBuf,
0, NULL );
// Display the error message and clean up
lpDisplayBuf = (LPVOID)LocalAlloc(LMEM_ZEROINIT,
(lstrlen((LPCTSTR)lpMsgBuf)+lstrlen((LPCTSTR)lpszFunction)+40)*sizeof(TCHAR));
StringCchPrintf((LPTSTR)lpDisplayBuf,
LocalSize(lpDisplayBuf) / sizeof(TCHAR),
TEXT("%s failed with error %d: %s"),
lpszFunction, dw, lpMsgBuf);
MessageBox(NULL, (LPCTSTR)lpDisplayBuf, TEXT("Error"), MB_OK);
LocalFree(lpMsgBuf);
LocalFree(lpDisplayBuf);
}
Gives out the followoing error on codeblocks:
fatal error: strcat.h: No such file or directory
#include <strcat.h>
^
compilation terminated.

Answer 1

strcat is defined in string.h not strcat.h
Then, you do not seem to be using strcat, maybe you can remove that.