C Language - What do these errors indicate in this short program?

Completely Clueless · 07-31-2010, 03:28 PM

Hi guys,

I'm writing a short program to create single .csv files from separate data source files but have run into some trouble. I cannot understand why I am getting these errors which I am sure will be quickly spotted by a professional programmer which I am obviously not!! Clue appreciated....

Code:

cvs_maker.c: In function ‘main’:
cvs_maker.c:7: error: parameter ‘userid’ is initialized
cvs_maker.c:7: error: declaration for parameter ‘userid’ but no such parameter
cvs_maker.c:6: error: declaration for parameter ‘loopcount’ but no such parameter
cvs_maker.c:65: warning: incompatible implicit declaration of built-in function ‘exit’

The program in question is below....

Code:

#include <stdio.h>
#include <string.h>

int main()

int loopcount;
int userid=1;

{

 FILE *users; 

  users=fopen("users.txt", "r"); 
  if(users==NULL) 
    { 
    printf("Error: can't open file.\n"); 
    return 1; 
    } 

  FILE *pass; 

  pass=fopen("pass.txt", "r"); 
  if(pass==NULL) 
    { 
    printf("Error: can't open file.\n"); 
    return 1; 
    } 

  FILE *target; 

  target=fopen("target.cvs", "w+"); 
  if(target==NULL) 
    { 
    printf("Error: can't create target file.\n"); 
    return 1; 
    } 


for (loopcount=0; loopcount<70; loopcount++); {

      char usr[8];    // array to store usernames
      char pwd[40];   // array to store the passwords

      fputs ("CSN00", target);
      fprintf (target, "%useridd");
      fputc (',', target);

      fgets (usr, 9, users);  // grabs first line of user file, inc./n
      usr[8]=',';             //overwrite the newline char with a comma
      fputs (usr, target);    
  

      fgets(pwd, 40, pass); 
      fputs(pwd, target);
      userid++;
    }


fclose (users);
fclose (pass);
fclose (target);

exit(0);

}

dugan · 07-31-2010, 03:44 PM

Start with this change:

Code:

int main()
{
    int loopcount;
    int userid=1;

    FILE *users; 
...

tommylovell · 07-31-2010, 04:03 PM

Certainly not a professional programmer, but

1) the exit function requires that you include stdlib.h

#include <stdlib.h>

2) move the two variables after the opening '{' or before the 'int main()'

Code:

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

int main()
{
int loopcount;
int userid=1;
.
.
.

Code:

#include <stdio.h>
#include <string.h>
#include <stdlib.h> 
int loopcount;
int userid=1;

int main()
{
.
.
.

Completely Clueless · 07-31-2010, 04:15 PM

Thanks, Dugan. It compiles fine now, although the final warning about the exit() function is still there. Oops! Tommy has fixed that too now. Thanks, guys!

Completely Clueless · 07-31-2010, 04:28 PM

Actually that is not quite right. The exit() warning message was fixed by the include <stdlib.h> preprocessor addition, but moving the variable declarations outside main() caused the gcc to give a segmentation error. But i's fine again now and thanks again.

kalleanka · 08-02-2010, 05:42 AM

and misspellt userid

fprintf (target, "%useridd");

Sergei Steshenko · 08-02-2010, 06:10 AM

Quote:

Originally Posted by Completely Clueless

... the final warning about the exit() function is still there. ...

How about

man 3 exit

?