Addition of numbers using threads

pthread.c

// Run 'gcc -pthread  pthread.c -o exec' to compile

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#define LINE_READ_SIZE 100


void *addAllNumbersFromList(void *listOfNumbers)
{
    int sumResult = 0;                                      // stores the result of sum
    char *token;                                            // tokenized value
    char *pointer = '\0';                                   // pointer for strtod
    const char stringDelimiter[2] = " ";                    // delimiter

    token = strtok(listOfNumbers, stringDelimiter);         // initial tokenization

    while(token != NULL)
    {
        sumResult = sumResult + strtod(token, &pointer);
        token = strtok(NULL, stringDelimiter);
    }
    
    if(sumResult != 0)
    {
        printf("Sum is %d\n", sumResult);        
    }
    pthread_exit(0);
}


int main(int argc, char *argv[])
{
    pthread_t thread; // thread ID
    
    char *terminalLineBuffer[LINE_READ_SIZE];               // for reading from terminal

    int terminalLineCount = read(STDIN_FILENO, &terminalLineBuffer, LINE_READ_SIZE);
    
    if(terminalLineCount < 0)
    {
        perror("Terminal Read Error");
        exit(0);
    }

    int threadReturnValue = pthread_create(&thread, NULL, addAllNumbersFromList, (void *) terminalLineBuffer); // create a thread task


    // Do some other work while thread is executing

    //sleep(2);
    write(STDOUT_FILENO, "Doing some other work...\n", sizeof("Doing some other work...\n"));
    
    // Finish doing some other work

    if(threadReturnValue < 0)
    {
        perror("Thread Error");
    }

    pthread_join(thread, NULL); // waits until a thread is complete so that the program doesn't exit before thread execution

}