gets(whatever) not work in some places

[non star]

i have a project that i'm working on and i faces this problem
that gets in line 123 isn't work
note:
the project should be totally in c

#include <stdlib.h>
#include <stdio.h>
#define size 1000000
#include <string.h>
void add_fractions (int a, int b, int c, int *d, int *ansn, int *ansd);
void subtract_fractions (int a, int b, int c, int *d, int *ansn, int *ansd);
void multiply_fractions (int a, int b, int c, int *d, int *ansn, int *ansd); 
void divide_fractions (int a, int *b, int c, int *d, int *ansn, int *ansd) ;
void simplify(int *ansn,int *ansd);
int wordcon(FILE *in);
 
int main ()
{
      int cho,cho1,x,z,a_num, b_denom, c_num, d_denom,ans1,ans2,numwd;
      FILE *in;
      char name[size];
    while (x!=0)
    {
          printf("please enter :\n1- Fraction addition\n2- Fraction subtraction\n3- Fraction multiplication\n4- Fraction division\n5- File processing\n6- Exit\n");
          scanf("%d",&cho);
          x=1;
          z=1;
        switch (cho){
               case 1:{
              printf ("Please enter the first numerator> \n"); 
              scanf ("%d", &a_num); 
 
              printf ("Please enter the first denominator> \n "); 
              scanf ("%d", &b_denom); 
 
              printf ("Please enter the second numerator> \n "); 
              scanf ("%d", &c_num); 
 
              printf ("Please enter the second denominator> \n "); 
              scanf ("%d", &d_denom); 
              add_fractions (a_num, b_denom, c_num, &d_denom,&ans1,&ans2);
              if (d_denom==0)
              printf("answer undefined\n");
              else 
              {
                   simplify(&ans1,&ans2);
                   printf("the answer is = %d/%d\n",ans1,ans2);
                   }
                   }
               break;
               case 2 :{
                printf ("Please enter the first numerator> \n"); 
              scanf ("%d", &a_num); 
 
              printf ("Please enter the first denominator> \n "); 
              scanf ("%d", &b_denom); 
 
              printf ("Please enter the second numerator> \n "); 
              scanf ("%d", &c_num); 
 
              printf ("Please enter the second denominator> \n "); 
              scanf ("%d", &d_denom); 
              subtract_fractions (a_num, b_denom, c_num, &d_denom,&ans1,&ans2);
              if (d_denom==0)
              printf("answer undefined\n");
              else 
              {
                   simplify(&ans1,&ans2);
                   printf("the answer is = %d/%d\n",ans1,ans2);
                   }
 
                 }
               break;
               case 3 :{
                printf ("Please enter the first numerator> \n"); 
              scanf ("%d", &a_num); 
 
              printf ("Please enter the first denominator> \n "); 
              scanf ("%d", &b_denom); 
 
              printf ("Please enter the second numerator> \n "); 
              scanf ("%d", &c_num); 
 
              printf ("Please enter the second denominator> \n "); 
              scanf ("%d", &d_denom); 
              multiply_fractions (a_num, b_denom, c_num, &d_denom,&ans1,&ans2);
              if (d_denom==0)
              printf("answer undefined\n");
              else 
              {
                   simplify(&ans1,&ans2);
                   printf("the answer is = %d/%d\n",ans1,ans2);
                   }
 
                 }
               break;
               case 4: {
                printf ("Please enter the first numerator> \n"); 
              scanf ("%d", &a_num); 
 
              printf ("Please enter the first denominator> \n "); 
              scanf ("%d", &b_denom); 
 
              printf ("Please enter the second numerator> \n "); 
              scanf ("%d", &c_num); 
 
              printf ("Please enter the second denominator> \n "); 
              scanf ("%d", &d_denom); 
              divide_fractions (a_num, &b_denom, c_num, &d_denom,&ans1,&ans2);
              if (d_denom==0||b_denom==0)
              printf("answer undefined\n");
              else 
              {
                   simplify(&ans1,&ans2);
                   printf("the answer is = %d/%d\n",ans1,ans2);
                   }
 
                 }
               break;
               case 5:{
                    while(z!=0){
                    printf("enter:\n1- count words in the file \n2- find and display characters with their frequencies \n3- search for a word in the file\n4- go to main menu\n5- Exit\n");    
                    scanf("%d",&cho1);
                       switch (cho1){
                           case 1:{
                                printf("Enter the name of file to be checked>\n");
                                char name[size];
                                gets(name);
                                in=fopen(name,"r");
                                if (in==NULL)
                                 {
                                   printf("ERROR - can't open file %s\n",name);
                                   system("pause");
                                   exit(0);
                                   }
                                numwd=wordcon(in);
                                printf("%d\n",numwd);
                                }
                                break;
                           case 2 :printf("sunday\n");
                           break;
                           case 3 :printf("monday\n");
                           break;
                           case 4: z=0;
                           break;
                           case 5:{x=0;
                                   z=0;}    
                           break;
                           default: printf("wrong input\n");
                           }}}
               break;
               case 6 :x=0;
               break;
               default: printf("wrong input\n");
               }}
           system("pause");
           return 0;
           }
 
           void simplify(int *ansn,int *ansd)
{
    int x,y,a,z,gcd,rem;
    x=*ansd;
    y=*ansn;
 
        if (y==0)
    gcd = x;
    else
    {
        do
        {
        rem = x%y;
        x = y;
        y = rem;
 
 
        }
        while (y!=0);
        gcd = x;
 
 
    }
    *ansd=*ansd/gcd;
    *ansn=*ansn/gcd;
}     
void add_fractions (int a, int b, int c, int *d, int *ansn, int *ansd)
{
    a = a*(*d);
    c = c*b;
    b = b*(*d);
    *d = b;   
 
 
    *ansn = a + c; 
    *ansd = *d; 
} 
void subtract_fractions (int a, int b, int c, int *d, int *ansn, int *ansd)
{
    a = a*(*d);
    c = c*b;
    b = b*(*d);
    *d = b;   
 
 
    *ansn = a - c; 
    *ansd = *d; 
}
void multiply_fractions (int a, int b, int c, int *d, int *ansn, int *ansd)
{
      a = a*c;
    c = a; 
    b = b**d; 
    *d = b;  
    *ansn = a; 
    *ansd = b; 
 
} 
 
void divide_fractions (int a, int *b, int c, int *d, int *ansn, int *ansd) 
{ 
    a = a*(*d); 
    *d = a;  
    *b = *b*c;  
    c = *b;     
 
    *ansn = a; 
    *ansd = *b; 
 
} 
int wordcon(FILE *in)
{
 
    char str[size];
    fgets(str, size, in);
    char delims[] = " ";
    char *token;
    int numwd=0;
    puts(str);
token = strtok( str, delims );
    while ( token != NULL ) {
        numwd++;
        token = strtok( NULL, delims );
    }
return numwd;
}
 
 
 

[mayankarpit]

Use fgets() instead of gets()

[non star]

how to use it with out a file

[Banfa]

The console, command prompt has file handles through which it is accessed:

stdout - the standard output stream, normally buffered
stderr - the error output stream normally unbuffered
stdin - the standard input stream, normally buffered

To use fgets to read user input instead of the using gets you use the file handle stdin

char text[100];
 
fgets(text, sizeof text, stdin);
 

[mayankarpit]

char buff[SOME_SIZE];
fgets(buff, sizeof(buff), stdin);

[non star]

still not working I've try these things and nothing different

[Banfa]

What makes you say it is not working?

[mayankarpit]

You should clearly explain desired behaviour from the code and the problem your are facing.

[non star]

@Banfa
try to compile the code and you will not be able to enter the file name in this step and it will be always null

printf("Enter the name of file to be checked>\n");
                                char name[size];
                                gets(name);
                                in=fopen(name,"r");
                                if (in==NULL)
                                 {
                                   printf("ERROR - can't open file %s\n",name);
                                   system("pause");
                                   exit(0);
                                   }

[Banfa]

No that code compiles and works fine for me once I put it in main and defined all the variables.

[non star]

me to but if i but it in the program it isn't work

[Banfa]

Well to start with make size a sensible value, 1000000 is rather asking for trouble.

When you say will always be null are you talking about the string name or the file pointer in?

[non star]

ok it was a sealy mistake it was about the size just about the size :(