Dos commands

[KyoAD]

Hi,

How do i call dos commands/programs in a C program? For example, to run 'dir' in the program? Can i do this by using the shell command? What libraries must i include?

 

[Salem]

Here's one way

#include <stdlib.h>

system( "dir" );

--

 

[fl0ra]

Actually if you wanna be much more precise you have to do:

#include <stdlib.h>
system( "command.com /c dir" );

Not sure it will work without the command.com... Have not tried with C (partly because I'm lazy) but in Tcl/Tk you have to specify command.com /c when it comes to internal commands such as dir

 

[columb]

system ( "dir" );

will work but....
If you want to create a list of files for processing inside your code then capturing the output of dir is not straingtforward. In fact I've seen

system ( "dir > \\temp\\flist" );
if ( ( fHandle = fopen ( "\\temp\\flist", "r" ) ) )
  {
  while ( fgets ( szBuffer, sizeof (szBuffer), fHandle ) )
  .....
  ....

which is barbaric but works
If you need a list of files the look at opendir and readdir

 

[Salem]

> If you need a list of files the look at opendir and readdir
Agreed.
Though the OP probably wants the DOS/Windows equivalents of findfirst and findnext.

However, which spelling of findfirst you should use seems dependent on your compiler, so some digging may be in order.

--

 

[fl0ra]

I generally do not program under windows.
however, can you not use channel redirection like u would on unix instead of > into a file and then read it?

 

[Salem]

Well

FILE *fp = popen( "dir", "r" );
while ( fgets ( buff, sizeof (buff), fp ) ) {
}
pclose( fp );

Gets around the temporary file problem, but it needs the POSIX libraries installed for it to work on windows.
It almost certainly isn't available in DOS.

--

 

[fl0ra]

yeah that is what I meant...
sorry for the bad explainations...