c programming copying files

Having few issues with my copy program which creates a copy of a file user enteres. I decided not to use (size_t) structure instead just assigned (int) and (char) types variables so I know exact value of bytes to read() out. ie I know start at beggining of file and read 4 bytes(int) to get value of lenght of filename, which I use as size in next read()

So, when I am writing (copying file exactly with same name) users inputted file to the output file (copied file) I writing it in long string, without spaces obviously just to make it readable here,

filenamesize filename filecontentsize filecontent ie 10 myfile.txt 5 hello

So when come to reading that data out I start at begining of file using lseek() and I know the first 4 bytes are (int) which is lenght of filename so I put that into value int namelen using the read function.

My problem is I want to use that value read for the filenamesize(first 4 bytes) to declare my array to store filename with the right lenght. How do I put this array into read() so the read stores value inside that char array specified, see below please

int namelen; //value read from first 4 bytes of file lenght of filename to go in nxt read开发者_如何学编程()
char filename[namelen]; 
read(fd, filename[namelen], namelen);//filename should have 'myfile.txt' if user entered that filename

So my question is once I read that first 4 bytes from file giving me lenght of filename stored in namelen, I then want to read namelen amount of bytes to give me the filename of originally file so I can create copied file inside directory?

Thanks

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int namelen; //value read from first 4 bytes of file lenght of filename to go in nxt read()
char* filename = new char[namelen+1]; 
read(fd, filename, namelen);
filename[namelen]=0; // Just to keep readed buffer c-string compatible
do something with filename
delete[] filename;

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In your previous question here, you did not upvote a single answer or accept any of them. You do appear to have used those answers though.

People who answered that earlier question might be inclined to help you here if you could be bothered to show a little gratitude for their earlier help by upvoting their answers and accepting the one that you found most helpful.