Simple strcmp program freezes upon scanf

Hello.

This is a simple program that imports a custom header file called 'myfunc.h,' which contains a defined prototype for an alternative strcmp function.

The code for the .c file is:

Code:

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


int main(void) {
	char* string1 = {0};
	char* string2 = {0};
	
	printf("Enter string1: ");
	scanf("%s", string1);
	printf("Enter string2: ");
	scanf("%s", string2);
	
	if (compstring(string1, string2) == 1) { printf("The two strings you entered are the same.\n"); }
	else { printf("The two strings you entered are different.\n"); }


	system("pause");


	return 0;
}

and this is the header file:

Code:

#include <string.h>


int compstring(char* str1, char* str2) {
	if (strcmp(str1, str2) == 0) { return 1; }
	else { return 0; }
}

Here is the resulting error:



Any ideas on what could be causing this? Thanks in advance.

try making the string a static array first it could make a difference, you have a string literal which can not be modified if im not mistaken

I suggest making string1 and string2 into arrays instead of a pointers.
Or, allocate space for each pointer to hold the data.

Tim S.

Originally Posted by stahta01

I suggest making string1 and string2 into arrays instead of a pointers.
Or, allocate space for each pointer to hold the data.

Tim S.

Thank you for your help.

I changed:

Code:

char* string1 = {0};
char* string2 = {0};

to:

Code:

char string1[] = {0};
char string2[] = {0};

and now the function returns 0 each time, even when the strings entered are the same, although I am not getting any errors during compile.

To reiterate, the custom header was:

Code:

#include <string.h>


int compstring(char* str1, char* str2) {
    if (strcmp(str1, str2) == 0) { return 1; }
    else { return 0; }
}

Why would the passed strings not return a value that indicates they are equivalent?

Thank you again.

You need to allocate space to hold the information.
You are allocating a single char per array; this is only enough to hold the empty string.

Try

Code:

char string1[255] = {0};

Tim S.

Originally Posted by drbr0wn

Why would the passed strings not return a value that indicates they are equivalent?

I tried this program:

Code:

#include <string.h>
#include <stdio.h> 
 
int compstring(char* str1, char* str2) {
    if (strcmp(str1, str2) == 0) { return 1; }
    else { return 0; }
}

int main(void) {
    char string1[] = {0};
    char string2[] = {0};
    printf("%d\n", compstring(string1, string2));
    return 0;
}

and it printed 1.

Originally Posted by stahta01

You need to allocate space to hold the information.
You are allocating a single char per array; this is only enough to hold the empty string.

Try

Code:

char string1[255] = {0};

Tim S.

Aha! Thank you!!!