Could someone explain why this happens

This is a discussion on Could someone explain why this happens within the C Programming forums, part of the General Programming Boards category; Hi everyone I was fiddling with some code ln and came across a dilemma ,here is the code Code: # ...

  1. #1
    Patent Pending GSLR's Avatar
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    Sep 2001
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    134

    Question Could someone explain why this happens

    Hi everyone

    I was fiddling with some code ln and came across a dilemma ,here is the code

    Code:
    # include <stdio.h>
    # include <conio.c>
    
    /********************************** FUNCTION PROTOTYPES ********************/
    
    int test(void);
    
    /********************************** BEGIN MAIN  ****************************/
    
    int main(int argv, char *argc[])
    {
     int number;
     printf("Enter a number:");
     scanf("%d",&number);
     switch (number){
                     case (1):
                             test();
                     break;
                     }
    
         system("PAUSE");
          return 0;
    }
    
    /********************************** FUNCTION ******************************/
    
    int test(void)
    {
    int f;
    char name_test[20];
    
    clrscr();
    printf("Program is here");
    //scanf("%d",&f);
    gets(name_test);
     printf(name_test);
     return 0;
     }
    ok so whats the problem, well if i run this program as is the gets function is never called or (skipped) so i never get to input some text.
    I found that if i put a scanf function just before the gets function the program halts and allows me to enter input into the char array.
    I found tht it was the switch command that was creating all this hassle and i was just wondering why?

    Thanx for your help.

  2. #2
    Open to suggestions Brighteyes's Avatar
    Join Date
    Mar 2003
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    204
    Don't mix scanf and gets, the newline that scanf tends to leave in the input stream immediately satisfies gets and you never get a chance to enter more data. You shouldn't be using gets anyway, there's no way to make it safe. Try this instead:
    Code:
    /* Read the data then ignore a single character, presumably the newline */
    scanf("%d%*c",&number);
    then
    Code:
    /* Use fgets to get the name */
    fgets(name_test, sizeof (name_test), stdin);
    p.s. What the alphabet would look like without q and r.

  3. #3
    Patent Pending GSLR's Avatar
    Join Date
    Sep 2001
    Posts
    134
    Hi

    ok i just tried to replace gets with fgets and when i run the program with the scanf function remed out it still skips the fgets function and doesnt allow me to enter the input from stdin.

    Thanx

    Code:
    # include <stdio.h>
    # include <conio.c>
    
    /********************************** FUNCTION PROTOTYPES ********************/
    
    int test(void);
    
    /********************************** BEGIN MAIN  ****************************/
    
    int main(int argv, char *argc[])
    {
     int number;
     printf("Enter a number:");
     scanf("%d",&number);
     switch (number){
                     case (1):
                             test();
                     break;
                     }
    
         system("PAUSE");
          return 0;
    }
    
    /********************************** FUNCTION ******************************/
    
    int test(void)
    {
    int f;
    char name_test[20];
    
    clrscr();
    printf("Program is here");
    //scanf("%d",&f);    /*i dont want to use this to pause prog flow
    fgets(name_test,20,stdin);                   /*MODIFIED LINE*/
     printf(name_test);
     return 0;
     }
    And To All Those Opposed, WELL !!!
    >Deleted< " Looks like a serial no."

  4. #4
    Patent Pending GSLR's Avatar
    Join Date
    Sep 2001
    Posts
    134
    Thanx Salem

    much appreciated.
    And To All Those Opposed, WELL !!!
    >Deleted< " Looks like a serial no."

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