Thread: Beginner and scanf

I'm trying to learn C programming in Linux, and I can get to the point where I can redirect the output of a file containing 4 numbers (1 2 3 4) that are space delimited to the input of a program that finds the highest number (4). Then when I try to comma, colon, or semi colon Delimite the same program i end up with the number 134513856 when my numbers are 1,2,3,4.

CLI programs separate parameters (arc and argv) based on spaces... not commas.

If you don't want to handle separate command line parameters, you could accept the string "1,2,3,4" as a single command line parameter and split it up on commas to get the individual numbers (strtok is one way).

I have a test coming up that involves me doing the following:

1.) Create a program that reads four numbers, space seperated, from a data file printing only the smallest.
2.) Create a program that reads four numbers, comma seperated, from a data file printing only the largest.
3.) Create a program that reads four numbers, colon seperated, from a data file printing only the odd numbers.
4.) Create a program that reads four numbers, simicolon seperated, from a data file printing only the even numbers.

That's what I'm going for, so am i reading the question wrong?

I'm wondering what I'm missing to allow the file being read into the program via comma's, colon's, and semicolons so that I can fulfill the requirements for the upcoming test.

I think so, yes. You're probably expected to use fopen, fread/fscanf and fclose. In your current method, your program doesn't actually read the data from a file.

Here's my teachers example program for us to study and readin file for his progam:

Readin: Filename = mydata
16,23,78

Program: p1.o

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

int main()
{
int i_a,i_b,i_c,i_sm;

scanf("%i,%i,%i",&i_a,&i_b,&i_c);

i_sm=i_a;

if(i_b < i_sm)
i_sm=i_b;

if(i_c < i_sm)
i_sm=i_c;

printf("The smallest number is %i\n",i_sm);

return(0);
}

My readin: filename = mydata
1,2,3,4

My program: p1.o
#include <stdio.h>
#include <stdlib.h>

int main()
{
int i_1,i_2,i_3,i_4,i_sm;

scanf("%i\n %i\n %i\n %i\n",&i_1,&i_2,&i_3,&i_4);

i_sm=i_1;

if(i_sm < i_2)
i_sm=i_2;

if (i_sm < i_3)
i_sm=i_3;

if (i_sm < i_4)
i_sm=i_4;

printf("The largest number is %i\n",i_sm);

return (0);
}


Am I missing something completely obvious?

Originally Posted by Chleborad

I have a test coming up that involves me doing the following:

1.) Create a program that reads four numbers, space seperated, from a data file printing only the smallest.
2.) Create a program that reads four numbers, comma seperated, from a data file printing only the largest.
3.) Create a program that reads four numbers, colon seperated, from a data file printing only the odd numbers.
4.) Create a program that reads four numbers, simicolon seperated, from a data file printing only the even numbers.

That's what I'm going for, so am i reading the question wrong?

Here, play with this and tell me if it gives you any ideas...

Code:

int _cdecl main(int argc, char *argv[])
{ int a,b,c;
  printf("3 coma separated numbers please :  ");
  if( scanf("%d , %d , %d",&a,&b,&c) < 3)
    puts("Input Error");
  printf("%d  %d  %d\n",a,b,c);
  return 0; }

OH!! Perfect thank you quzah!! That makes perfect sense, sorry for not getting it right away.