C program that executes command fails with sleep - c

Question

I wrote a program that read a bash file line by line and execute its command written inside.
It seems to execute standard command normally (albeit there is not output on the terminal), but when it reads the sleep command, there is an error:
sleep 3: missing operand
Try 'sleep 3 --help' for more information.
char** string_separator(char* string, const char a_delim)
{
char** result = 0;
size_t count = 0;
char* tmp = string;
char* last_dot = 0;
char delimiter[2];
delimiter[0] = a_delim;
delimiter[1] = 0;
while (*tmp)
{
if (a_delim == *tmp)
{
count++;
last_dot = tmp;
}
tmp++;
}
count += last_dot < (string + strlen(string) - 1);
count++;
result = malloc(sizeof(char*) * count);
if (result)
{
size_t idx = 0;
char* token = strtok(string,delimiter);
while (token)
{
assert(idx < count);
*(result + idx++) = strdup(token);
token = strtok(0, delimiter);
}
assert(idx == count - 1);
*(result + idx) = 0;
}
return result;
}
int main(int argc, char *argv[]) {
for (int i = 1; i < argc; i++) {
FILE * fp;
fp = fopen(argv[i], "r");
char buf[100];
int bytes_read = 0;
char * inputCopy = malloc(255 * sizeof(char));
const char delim[] = " ";
while (fgets(buf, sizeof buf, fp) != NULL) {
if (strstr(buffer, "#!/")) {
} else {
char ** strtoken = string_separator(buf, '\n');
char * firstWord = getFirstWord(buf, inputCopy, delim);
pid_t pid;
pid = fork();
if (pid == 0) {
execvpe(firstWord, strtoken, NULL);
exit(1);
} else {
int status;
waitpid(pid, & status, 0);
}
}
}
}
return 0;
}
Why is the program not working with the sleep command?
EDIT: Made the modification in the code such as function definition and indentation, I think the problem might be with the string_separator function, it might not separate the string into char array as expected.