How would I use a null terminator in a char array so when I use fgets for input, it does not make a new line without using string libraries?

Question

I know I essentially need to replace the "\n" with a "\0", but how would I access the array to incorporate this? I can not use string.h library or any other libraries.

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


int main() {

    char buffer[32];
    char digits[3];

    printf("Enter name:");
    fgets(buffer,32,stdin);



    printf("Enter age:");
    fgets(digits,3,stdin);

    char *name;
    name = buffer;

    int *age;
    age = atoi(digits);

    happyBirthday(name,age);

    return 0;
}

`buffer[strcspn(buffer, "\r\n")] = 0;` (this must be a duplicate) — wildplasser, Sep 08 '21 at 20:00
I was told to use three digits max for some reason in the assignment lol. — AMCode96, Sep 08 '21 at 20:03
`int *age` should be `int age`. You should have gotten warnings about your code. — Barmar, Sep 08 '21 at 20:04
`char digits[3]` only allows 2 digits plus the null terminator. — Barmar, Sep 08 '21 at 20:05
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/236915/discussion-between-amcode96-and-barmar). — AMCode96, Sep 08 '21 at 20:08
`string.h` is not a library. It is a header. This is not mere pedantry; it is a fundamental misconception. — William Pursell, Sep 08 '21 at 20:14
Do you know how to loop over an array? And do you know how to compare two characters? If you can do both of those things, you can do this. — Chris, Sep 08 '21 at 20:19
Related: [Removing trailing newline character from fgets() input](https://stackoverflow.com/q/2693776/12149471) (Probably not a duplicate because OP has stated restrictions in the question). — Andreas Wenzel, Sep 08 '21 at 20:48

score 2 · Accepted Answer · answered Sep 08 '21 at 20:20

2

int i = 0;
while (buffer[i] != '\0')
{
    if (buffer[i] == '\n') buffer[i] = '\0';
    ++i;
}

answered Sep 08 '21 at 20:20

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Or more succinctly using a for loop: `for (int i = 0; buffer[i] != '\0'; i++) { if (buffer[i] == '\n') { buffer[i] = '\0'; } }` We could even use pointer arithmetic to take out the unnecessary `i` variable. Though `i`, if not locally scoped to the loop, could be useful for keeping track of the length of the resulting string. – Chris Sep 08 '21 at 20:37

How would I use a null terminator in a char array so when I use fgets for input, it does not make a new line without using string libraries?

1 Answers1