Programming Forums > Application Development > C++

Marijan · May 16th, 2008, 7:29 AM

The end of my first school year as a programmer is closing in.We heave learned the basic things of C++ programming.I have been doing quite good in programming so far and i passed my exam with 9 grade(9/10).But the real chalenge for me came today.I have accepted to write a program which will help me pass the 2nd exam.I am not quite sure if i can do it all alone,but it's ok since i am allowed to use all the sources avaliable to me.So far this community has been really helpfull for me and i hope it will stay that way.
The assistant of my programming professor came with a smart idea that i should make a program that will compare files in 1 folder and all of it's subfolders.It should compare their names,their size,if they are hidden and system files.And if these conditions are true it should print the names of those files and their locations.
I want you to know that my primary objective is to learn how to program and i,by any means don't want anyone to write this thing for me,i only need some kind of starting tips and pointers and some usefull thing that will help me writing my program.
Thanks in advance.

Ancient Dragon · May 16th, 2008, 8:15 AM

You need to call a system function to get a list of all the files in a folder. Then use recurson to process all its subfolders, and subfolders of the subfolders.

_findfirst() and _findnext() are useful functions to do that. google for those functions and you will find lots of examples. Here is just one of many.

Sorrofix · May 16th, 2008, 1:20 PM

Which operating system do you intend to write this program for?

grumpy · May 16th, 2008, 2:13 PM

Quote:

Originally Posted by Marijan

The assistant of my programming professor came with a smart idea that i should make a program that will compare files in 1 folder and all of it's subfolders.It should compare their names,their size,if they are hidden and system files.And if these conditions are true it should print the names of those files and their locations.

Firstly, you need to be aware that your program cannot be written in standard C++: the means getting names of files, their size, and attributes (system or hidden) are not part of C++. They are associated with the operating system your program will run on. Getting a list of files involves functions like findfirst()/findnext() [unix, with some portability to Windows], _findfirst(), _findnext() [typically under windows, but technically library extensions], FindFirstFile()/FindNextFile() [win 32], and other functions on other operating systems. Getting their attributes (eg are they a file or a directory, hidden/system state) also often involves functions and data structures that are operating system specific.

Second, I consider that the value in your exercise is learning to practically cope with the need to use C++ with functions/data structures/ etc that go outside scope of the C++ standard. I suggest you consider ways to structure your program to aid portability (eg have a set of functions that your code calls, which calls the right functions depending on operating system). This will be useful in terms of learning how to DETECT what operating system your code is on (eg compiler/OS specific macros), writing a program so it will compiler and then execute despite calling different functions, and use of build techniques (eg makefiles) to help with that. Keep in mind that it is usually a good idea to ensure the bulk of your code is portable (ie standard C++), so the trick is to minimise effort to achieve that. If you have more than one call of functions like findfirst() and findnext() in your code, it is not portable -- consider how you would address the problem of getting the result of functions like findfirst() to your code, without calling findfirst() on multiple places in your code because, if you call it multiple times, you need to modify that code every time you change operating system.

Actually try (i.e. have it as a specific goal) to produce a code base that will work on two different operating systems. Such as windows and a unix variant. You will encounter various portability issues, but addressing those issues will be a useful practical learning exercise for you.

Marijan · May 17th, 2008, 5:41 AM

Thanks a lot,just for information i intend on making a program for windows,but just as grumpy suggested i may try to make it useable on more operating systems.

Marijan · May 19th, 2008, 7:06 AM

Ok, i did a research for those functions and i also found out what recursion is.But maybe i am a bit thick or i can't think straight these days because i can't find out how to use these functions properly.
When i try to use the function on some already declared string that contains the path of the file name,it makes some problems like:"Cannot convert constant char to char"

Ancient Dragon · May 19th, 2008, 8:34 AM

Please post your code so that someone can help you.

Marijan · May 19th, 2008, 5:15 PM

Ok this is a simple code that i made just to test this function

<c++> Syntax (Toggle Plain Text)

 
int main()
{
  string path,result;
  path="C:\\";
  result=_findfirst(path)
  cout<<result<<endl;
 
 
 
 
    system("PAUSE");
	return 0;
 
 
}

I wrote this without knowing what the function exactly does,just for a test as i said.

Ancient Dragon · May 19th, 2008, 10:19 PM

Quote:

Originally Posted by Marijan

I wrote this without knowing what the function exactly does,just for a test as i said.

You need to learn how to look up the functions you don't understand. Just google for the function name and you will find a lot of help (usually).

Had you read this you would have found that

Quote:

If successful, _findfirst returns a unique search handle identifying the file or group of files matching the filespec specification, which can be used in a subsequent call to _findnext, or to _findclose. Otherwise, _findfirst will return –1 and set errno to one of the following values:

>>path="C:\\";
you need to add * for the search criteria. Just the beginning directory won't work
path="C:\\*.*"

Marijan · May 20th, 2008, 2:53 PM

Ok thanks for supporting me and helping me so far.I have used google and menaged to write something on my own using some already made programs.I came up with this code:

<c++> Syntax (Toggle Plain Text)

 
#include <direct.h>
#include <stdio.h>
#include <string>
#include <iostream>
#include <time.h>
 
using namespace std;
 
int main()
{
   char path[50];
   struct _finddata_t cfile;
   intptr_t  File;
   char buf[50];
   cout<<"Enter the path"<<endl;
   cin>>path;
 
   _chdir(path);
 
   File= _findfirst("*.*",&cfile);
 
 
   printf("Listing of files in the directory %s\n\n", path);
   printf("\nRDO HID SYS ARC  FILE                            DATE %20c SIZE\n", ' ');
   printf("--- --- --- ---  ----                             ---- %20c ----\n", ' ');
   printf((cfile.attrib & _A_RDONLY) ? " Y  " : " N  ");
   printf((cfile.attrib & _A_SYSTEM) ? " Y  " : " N  ");
   printf((cfile.attrib & _A_HIDDEN) ? " Y  " : " N  ");
   printf((cfile.attrib & _A_ARCH)   ? " Y  " : " N  "); 
 
   printf(" %-30s %.20s  %9ld\n", cfile.name, buf, cfile.size);
 
 
      system("PAUSE");
      return EXIT_SUCCESS;
 
}

It does...something,it lists only files in the folder you select.But i still seem to be far from my objective.

P.S. I am a C++ "programer"(lol),so i use cout always,i copied the printf commands from another code and i tried replacing them with the cout command,but it prints out sucessfully only cfile.attrib and i don't understand the rest

.
And sorry if i am being annoying.

May 16th, 2008, 7:29 AM	#1
Marijan Newbie Join Date: Feb 2008 Posts: 15 Rep Power: 0	File comparison program The end of my first school year as a programmer is closing in.We heave learned the basic things of C++ programming.I have been doing quite good in programming so far and i passed my exam with 9 grade(9/10).But the real chalenge for me came today.I have accepted to write a program which will help me pass the 2nd exam.I am not quite sure if i can do it all alone,but it's ok since i am allowed to use all the sources avaliable to me.So far this community has been really helpfull for me and i hope it will stay that way. The assistant of my programming professor came with a smart idea that i should make a program that will compare files in 1 folder and all of it's subfolders.It should compare their names,their size,if they are hidden and system files.And if these conditions are true it should print the names of those files and their locations. I want you to know that my primary objective is to learn how to program and i,by any means don't want anyone to write this thing for me,i only need some kind of starting tips and pointers and some usefull thing that will help me writing my program. Thanks in advance.

May 16th, 2008, 8:15 AM	#2
Ancient Dragon PFO God In Training Join Date: Jun 2005 Location: near St Louis, MO. (USA) Posts: 544 Rep Power: 4	Re: File comparison program You need to call a system function to get a list of all the files in a folder. Then use recurson to process all its subfolders, and subfolders of the subfolders. _findfirst() and _findnext() are useful functions to do that. google for those functions and you will find lots of examples. Here is just one of many. __________________ True Terror is to wake up one morning and discover that your high school class is running the country - Kurt Vonnegut Jr.

May 16th, 2008, 1:20 PM	#3
Sorrofix Expert Bug Developer Join Date: Apr 2008 Posts: 21 Rep Power: 0	Re: File comparison program Which operating system do you intend to write this program for?

May 17th, 2008, 5:41 AM	#5
Marijan Newbie Join Date: Feb 2008 Posts: 15 Rep Power: 0	Re: File comparison program Thanks a lot,just for information i intend on making a program for windows,but just as grumpy suggested i may try to make it useable on more operating systems.

May 19th, 2008, 7:06 AM	#6
Marijan Newbie Join Date: Feb 2008 Posts: 15 Rep Power: 0	Re: File comparison program Ok, i did a research for those functions and i also found out what recursion is.But maybe i am a bit thick or i can't think straight these days because i can't find out how to use these functions properly. When i try to use the function on some already declared string that contains the path of the file name,it makes some problems like:"Cannot convert constant char to char"

May 19th, 2008, 8:34 AM	#7
Ancient Dragon PFO God In Training Join Date: Jun 2005 Location: near St Louis, MO. (USA) Posts: 544 Rep Power: 4	Re: File comparison program Please post your code so that someone can help you. __________________ True Terror is to wake up one morning and discover that your high school class is running the country - Kurt Vonnegut Jr.

May 19th, 2008, 5:15 PM	#8
Marijan Newbie Join Date: Feb 2008 Posts: 15 Rep Power: 0	Re: File comparison program Ok this is a simple code that i made just to test this function <c++> Syntax (Toggle Plain Text) int main() { string path,result; path="C:\\"; result=_findfirst(path) cout<<result<<endl; system("PAUSE"); return 0; } int main() { string path,result; path="C:\\"; result=_findfirst(path) cout<<result<<endl; system("PAUSE"); return 0; } I wrote this without knowing what the function exactly does,just for a test as i said.

May 20th, 2008, 2:53 PM	#10
Marijan Newbie Join Date: Feb 2008 Posts: 15 Rep Power: 0	Re: File comparison program Ok thanks for supporting me and helping me so far.I have used google and menaged to write something on my own using some already made programs.I came up with this code: <c++> Syntax (Toggle Plain Text) #include <direct.h> #include <stdio.h> #include <string> #include <iostream> #include <time.h> using namespace std; int main() { char path[50]; struct _finddata_t cfile; intptr_t File; char buf[50]; cout<<"Enter the path"<<endl; cin>>path; _chdir(path); File= _findfirst(".",&cfile); printf("Listing of files in the directory %s\n\n", path); printf("\nRDO HID SYS ARC FILE DATE %20c SIZE\n", ' '); printf("--- --- --- --- ---- ---- %20c ----\n", ' '); printf((cfile.attrib & _A_RDONLY) ? " Y " : " N "); printf((cfile.attrib & _A_SYSTEM) ? " Y " : " N "); printf((cfile.attrib & _A_HIDDEN) ? " Y " : " N "); printf((cfile.attrib & _A_ARCH) ? " Y " : " N "); printf(" %-30s %.20s %9ld\n", cfile.name, buf, cfile.size); system("PAUSE"); return EXIT_SUCCESS; } #include <direct.h> #include <stdio.h> #include <string> #include <iostream> #include <time.h> using namespace std; int main() { char path[50]; struct _finddata_t cfile; intptr_t File; char buf[50]; cout<<"Enter the path"<<endl; cin>>path; _chdir(path); File= _findfirst(".",&cfile); printf("Listing of files in the directory %s\n\n", path); printf("\nRDO HID SYS ARC FILE DATE %20c SIZE\n", ' '); printf("--- --- --- --- ---- ---- %20c ----\n", ' '); printf((cfile.attrib & _A_RDONLY) ? " Y " : " N "); printf((cfile.attrib & _A_SYSTEM) ? " Y " : " N "); printf((cfile.attrib & _A_HIDDEN) ? " Y " : " N "); printf((cfile.attrib & _A_ARCH) ? " Y " : " N "); printf(" %-30s %.20s %9ld\n", cfile.name, buf, cfile.size); system("PAUSE"); return EXIT_SUCCESS; } It does...something,it lists only files in the folder you select.But i still seem to be far from my objective. P.S. I am a C++ "programer"(lol),so i use cout always,i copied the printf commands from another code and i tried replacing them with the cout command,but it prints out sucessfully only cfile.attrib and i don't understand the rest . And sorry if i am being annoying. Last edited by Marijan; May 20th, 2008 at 3:09 PM.

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Programming Forums > Application Development > C++

File comparison program