Thread: Looping problem.

Maybe something like this:

Code:

#define LINES_TO_DISPLAY 20

void dataPrint(void)
{
   unsigned int lines = 0;
   FILE *inFile;
   data_struct data;
   inFile = openFile(inFileName, "rb+");
   data= readData(inFile);
   while ( !feof(inFile) )
   {
      displaydata(data);
      if ( lines++ % LINES_TO_DISPLAY == (LINES_TO_DISPLAY - 1) )
      {
         int ch;
         fputs("Press enter to continue...", stdout);
         fflush(stdout);
         while ( (ch = getchar()) != '\n' && ch != EOF )
            ;
      }
      data = readData(inFile);
   }
   closeFile(inFile);
}

Originally Posted by prepare

Code:

if ( lines++ % LINES_TO_DISPLAY == (LINES_TO_DISPLAY - 1) )

So you increment lines by 1, then i dont really understand the rest

This will be true every 20 times.

• 0% 20 == 0
• 1 %20 == 1
• ...
• 18 % 20 == 18
• 19 % 20 == 19
• 20 % 20 == 0
• 21 % 20 == 1
• ...

[EDIT=2]

Code:

#include <stdio.h>

#define MAGIC_NUMBER 5

int main(void)
{
   unsigned int i;
   for ( i = 0; i < 3 * MAGIC_NUMBER + 1; ++i )
   {
      printf("%2u %% %u == %u", i, MAGIC_NUMBER, i % MAGIC_NUMBER);
      if ( i % MAGIC_NUMBER == (MAGIC_NUMBER - 1) )
      {
         printf("<--");
      }
      putchar('\n');
   }
   return 0;
}

/* my output
 0 % 5 == 0
 1 % 5 == 1
 2 % 5 == 2
 3 % 5 == 3
 4 % 5 == 4<--
 5 % 5 == 0
 6 % 5 == 1
 7 % 5 == 2
 8 % 5 == 3
 9 % 5 == 4<--
10 % 5 == 0
11 % 5 == 1
12 % 5 == 2
13 % 5 == 3
14 % 5 == 4<--
15 % 5 == 0
*/

[/EDIT]

Originally Posted by prepare

Code:

fputs("Press enter to continue...", stdout);

fputs, just like printf but for stings right?. stdout = standard out? not sure what that means

You pretty much nailed it.

Originally Posted by prepare

Code:

fflush(stdout);

fflush? clearing the value of stdout??

fflush(stdout)

Originally Posted by prepare

Code:

while ( (ch = getchar()) != '\n' && ch != EOF )

lost me a bit here to...keep looping with user input or until EOF?

How do I get my program to wait for a keypress?


[EDIT=1]

Originally Posted by prepare

why an unsigned int?

If I don't expect negative values, I try to use a more appropriate type.