Can't modify an array within a loop (C) - c

Question

I am currently developing a small program requires a function to return a string (character array), and two parameters which are (phrase, c). The 'phrase' is a string input and 'c' is the character which will be removed from the phrase. The left-over spaces will also be removed.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
//This method has two parameters: (str, c)
//It will remove all occurences of var 'c'
//inside of 'str'
char * rmchr(char * str, char *c) {
//Declare result array
char *strVal = (char *) malloc(sizeof(char) * strlen(str));
//Iterate through each character
for (int i = 0; i < strlen(str); i++) {
*(strVal+i) = str[i];
//Check if char matches 'c'
if (strVal[i] != *c){
//Assign filtered value to new array
*(strVal+i) = str[i];
printf("%c", strVal[i]);
}
}
return strVal;
}
int main()
{
char * result = rmchr("This is a great message to test with! It includes a lot of examples!","i");
return 1;
}
Inside of the 'rmchr' function (if-statement), the array prints out exactly how I'd like to return it:
Ths s a great message to test wth! It ncludes a lot of examples!
The problem is that my return variable, 'strVal' isn't being modified outside of the if-statement. How can I modify the array permanently so my ideal output will be returned inside of 'result' (inside of main).

Answer 1

I see a few points to address. Primarily, this code directly copies the input string verbatim as it stands. The same *(strVal+i) = str[i]; assignment takes place in two locations in the code which disregards the comparison against *c. Without some secondary index variable j, it becomes difficult to keep track of the end of the receiving string.
Additional notes:
There is no free for your malloc; this creates a memory leak.
You return exit code 1 which indicates abnormal program termination. return 0 to indicate a normal exit.
Don't cast the pointer malloc returns; this can hide errors.
Validate malloc success and exit if it failed.
strlen() is a linear time operation that iterates through the entire parameter string on each call. Call it once and store the result in a variable to save cycles.
This code does not handle removal of extra spaces as required.
See the below sample for a possible implementation that addresses some of the above points:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
char *rmchr(char *str, char *c) {
int i = 0;
int j = 0;
int len = strlen(str);
char *result = malloc(sizeof(*result) * (len + 1));
if (result == NULL) {
fprintf(stderr, "out of memory\n");
exit(1);
}
while (i < len) {
if (str[i] != *c) {
result[j++] = str[i++];
}
else {
for (i++; i < len && str[i] == ' '; i++);
}
}
result[j] = '\0';
return result;
}
int main() {
char *result = rmchr("This is a great message to test with! It includes a lot of examples!", "i");
for (int i = 0; i < strlen(result); i++) {
printf("%c", result[i]);
}
free(result);
return 0;
}
Output:
Ths s a great message to test wth! It ncludes a lot of examples!