Programming Forums > Application Development > C

mechmind · Feb 3rd, 2005, 8:38 AM

Hi,
I need to copy a log file to a new location called the old_logs directory. What function can I use in c to copy the file form "c:\log" to "c:\old_logs\log"?

cheers,
mechmind

Ooble · Feb 3rd, 2005, 10:15 AM

There isn't a function, as such. You need to get a list of the files, open each file, read it into memory, write the data to the new file, and close it. You can then delete each file with the unlink function if you want.

Eggbert · Feb 3rd, 2005, 12:00 PM

Using nothing but portable ISO C, the simplest useful program would be:

(Toggle Plain Text)

#include <stdio.h>
#include <stdlib.h>

int main ( int argc, char *argv[] )
{
  FILE *in, *out;
  int byte;

  if ( argc < 3 ) {
    fprintf ( stderr, "usage: prog <filefrom> <fileto>\n" );
    return EXIT_FAILURE;
  }

  in = fopen ( argv[1], "r" );
  if ( in == NULL ) {
    fprintf ( stderr, "Error opening file\n" );
    return EXIT_FAILURE;
  }

  out = fopen ( argv[2], "w" );
  if ( out == NULL ) {
    fprintf ( stderr, "Error opening file\n" );
    return EXIT_FAILURE;
  }

  while ( ( byte = fgetc ( in ) ) != EOF )
    fputc ( byte, out );

  fclose ( in );
  fclose ( out );
  remove ( argv[1] );

  return EXIT_SUCCESS;
}

However, calling out to the environment would be far simpler:

(Toggle Plain Text)

#include <stdio.h>
#include <stdlib.h>

int main ( int argc, char *argv[] )
{
  char buffer[BUFSIZ];

  if ( argc < 3 ) {
    fprintf ( stderr, "usage: prog <filefrom> <fileto>\n" );
    return EXIT_FAILURE;
  }

  sprintf ( buffer, "MOVE /Y %s %s", argv[1], argv[2] );
  system ( buffer );

  return EXIT_SUCCESS;
}

>You can then delete each file with the unlink function if you want.
unlink is not a portable function. remove is the standard C equivalent.

Ooble · Feb 3rd, 2005, 4:11 PM

Really? Never used it myself, but my C book says it works in Linux and Windows. Meh. You're the don.

mechmind · Feb 5th, 2005, 8:58 PM

Great! Thanks for the help!

Regards,
Mechmind

badbasser98 · Jun 10th, 2005, 11:14 AM

anyone have more info on how to use the remove function for C++...

thanx,
BB98

Ancient Dragon · Jun 10th, 2005, 11:42 AM

Quote:

Originally Posted by badbasser98

anyone have more info on how to use the remove function for C++...

thanx,
BB98

The remove() function?? there isn't anything to it. all it does is delete a file. You will find it described in any C or C++ book, www.msdn.microsoft.com or probably a lot of other places on the net (use google to find them). But its such a trival thing to use that it doesn't take but a few seconds to learn it.

Move files: If you are using MS-Windows operating system, you can use Win32 API function CopyFile().

nnxion · Jun 10th, 2005, 11:47 AM

The remove function.

badbasser98 · Jun 10th, 2005, 12:28 PM

Well I guess I should have been more specific. You can give the function a file path, correct? So how does that work if the "\" symbol is an escape character to the compiler. (ie. "\n" for a new line.) How you you give C:\program files\adobe\acrobat 7.0\AcroRd32.exe for example. Does it have to be in double parens?

Sorry for being so stupid, just bought my C++ book last night, am trying to come up from C.

thanx,
BB98

[Edit] Thanx for the replies, starting to straighten out in my thick head.[\edit]

DaWei · Jun 10th, 2005, 12:31 PM

Escape characters aren't a C++ thang. Escape the escape character. That would be "\\".

Feb 3rd, 2005, 8:38 AM	#1
mechmind Newbie Join Date: Feb 2005 Posts: 3 Rep Power: 0	how to copy files from one place to another in c Hi, I need to copy a log file to a new location called the old_logs directory. What function can I use in c to copy the file form "c:\log" to "c:\old_logs\log"? cheers, mechmind

Feb 3rd, 2005, 10:15 AM	#2
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	There isn't a function, as such. You need to get a list of the files, open each file, read it into memory, write the data to the new file, and close it. You can then delete each file with the unlink function if you want. __________________ Me :: You :: Them

Feb 3rd, 2005, 12:00 PM	#3
Eggbert Professional Programmer Join Date: Nov 2004 Posts: 250 Rep Power: 4	Using nothing but portable ISO C, the simplest useful program would be: (Toggle Plain Text) #include <stdio.h> #include <stdlib.h> int main ( int argc, char argv[] ) { FILE in, out; int byte; if ( argc < 3 ) { fprintf ( stderr, "usage: prog <filefrom> <fileto>\n" ); return EXIT_FAILURE; } in = fopen ( argv[1], "r" ); if ( in == NULL ) { fprintf ( stderr, "Error opening file\n" ); return EXIT_FAILURE; } out = fopen ( argv[2], "w" ); if ( out == NULL ) { fprintf ( stderr, "Error opening file\n" ); return EXIT_FAILURE; } while ( ( byte = fgetc ( in ) ) != EOF ) fputc ( byte, out ); fclose ( in ); fclose ( out ); remove ( argv[1] ); return EXIT_SUCCESS; } #include <stdio.h> #include <stdlib.h> int main ( int argc, char argv[] ) { FILE in, out; int byte; if ( argc < 3 ) { fprintf ( stderr, "usage: prog <filefrom> <fileto>\n" ); return EXIT_FAILURE; } in = fopen ( argv[1], "r" ); if ( in == NULL ) { fprintf ( stderr, "Error opening file\n" ); return EXIT_FAILURE; } out = fopen ( argv[2], "w" ); if ( out == NULL ) { fprintf ( stderr, "Error opening file\n" ); return EXIT_FAILURE; } while ( ( byte = fgetc ( in ) ) != EOF ) fputc ( byte, out ); fclose ( in ); fclose ( out ); remove ( argv[1] ); return EXIT_SUCCESS; } However, calling out to the environment would be far simpler: (Toggle Plain Text) #include <stdio.h> #include <stdlib.h> int main ( int argc, char argv[] ) { char buffer[BUFSIZ]; if ( argc < 3 ) { fprintf ( stderr, "usage: prog <filefrom> <fileto>\n" ); return EXIT_FAILURE; } sprintf ( buffer, "MOVE /Y %s %s", argv[1], argv[2] ); system ( buffer ); return EXIT_SUCCESS; } #include <stdio.h> #include <stdlib.h> int main ( int argc, char argv[] ) { char buffer[BUFSIZ]; if ( argc < 3 ) { fprintf ( stderr, "usage: prog <filefrom> <fileto>\n" ); return EXIT_FAILURE; } sprintf ( buffer, "MOVE /Y %s %s", argv[1], argv[2] ); system ( buffer ); return EXIT_SUCCESS; } >You can then delete each file with the unlink function if you want. unlink is not a portable function. remove is the standard C equivalent.

Feb 3rd, 2005, 4:11 PM	#4
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	Really? Never used it myself, but my C book says it works in Linux and Windows. Meh. You're the don. __________________ Me :: You :: Them

Jun 10th, 2005, 11:47 AM	#8
nnxion Programming Guru Join Date: Jun 2005 Location: elemental plane Posts: 1,429 Rep Power: 5	The remove function. __________________ "Employ your time in improving yourself by other men's writings, so that you shall gain easily what others have labored hard for." -- Socrates

Feb 5th, 2005, 8:58 PM	#5
mechmind Newbie Join Date: Feb 2005 Posts: 3 Rep Power: 0	Great! Thanks for the help! Regards, Mechmind

Jun 10th, 2005, 11:14 AM	#6
badbasser98 Hobbyist Programmer Join Date: Mar 2005 Location: United States Posts: 124 Rep Power: 4	anyone have more info on how to use the remove function for C++... thanx, BB98

Jun 10th, 2005, 12:28 PM	#9
badbasser98 Hobbyist Programmer Join Date: Mar 2005 Location: United States Posts: 124 Rep Power: 4	Well I guess I should have been more specific. You can give the function a file path, correct? So how does that work if the "\" symbol is an escape character to the compiler. (ie. "\n" for a new line.) How you you give C:\program files\adobe\acrobat 7.0\AcroRd32.exe for example. Does it have to be in double parens? Sorry for being so stupid, just bought my C++ book last night, am trying to come up from C. thanx, BB98 [Edit] Thanx for the replies, starting to straighten out in my thick head.[\edit]

Jun 10th, 2005, 12:31 PM	#10
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	Escape characters aren't a C++ thang. Escape the escape character. That would be "\\". __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Programming Forums > Application Development > C

how to copy files from one place to another in c