pword.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <mqueue.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <string.h>
#include <ctype.h>
#include <time.h>

#include "tree.h"

#define MIN_ARGS 4
#define MAX_FILES 8
#define MAX_SIZE 64

#define MQNAME "/MQNAME"
#define STOP_SIGNAL "EOF"

char files[MAX_FILES][255];

char *toUpperCase(char *str);

int main(int argc, char const *argv[])
{

    int file_num;
    int message_size;
    mqd_t mq;
    struct mq_attr mq_attr;
    struct timeval time1, time2;

    if (argc < MIN_ARGS || argc > MIN_ARGS + MAX_FILES)
    {
        fprintf(stderr, "Argument number is inappropriate!\n");
        exit(-1);
    }
    else
    {
        file_num = atoi(argv[3]);
        message_size = atoi(argv[1]);

        if (argc != MIN_ARGS + file_num)
        {
            fprintf(stderr, "File number and existing files are incompatible!\n");
            exit(-1);
        }
        else
        {
            for (int i = 0; i < file_num; i++)
            {
                strcpy(files[i], argv[MIN_ARGS + i]); // storing the file names
            }

            gettimeofday(&time1, NULL);

            mq = mq_open(MQNAME, O_RDWR | O_CREAT, 0666, NULL);
            mq_getattr(mq, &mq_attr);
            int bufflen = mq_attr.mq_msgsize;
            char *bufferp;

            if (mq == -1) 
            {
                perror("Parent) Message Queue cannot be opened!\n");
                exit(1);
            }

            for(int i = 0; i < file_num; i++)
            {  
                pid_t n = fork();
                if(n == 0) // child process execution
                {
                    mq = mq_open(MQNAME, O_RDWR);

                    bufferp = (char *) malloc(bufflen);

                    char str[message_size];

                    strcpy(str, "");
                    
                    FILE *fp = fopen(files[i], "r");

                    char file_str[MAX_SIZE] = "";

                    while ( fscanf(fp, "%s", file_str) != EOF )
                    {
                        if (strlen(str) + strlen(file_str) + 1 > message_size)
                        {
                            mq_send(mq, str, message_size, 0);
                            strcpy(str, "");
                        }
                            
                        strcat(str, file_str);
                        strcat(str, " ");
                    }
                    mq_send(mq, str, message_size, 0);
                    
                    mq_send(mq, STOP_SIGNAL, message_size, 0);

                    mq_close(mq);
                    fclose(fp);
                    exit(0);
                }

            }

            int stop_count = 0;

            struct Node *root = NULL;

            while (stop_count != file_num)
            {
                int bufferlen = mq_attr.mq_msgsize;
                bufferp = (char *) malloc(bufferlen);

                mq_receive(mq, bufferp, bufferlen, NULL);

                if (strcmp(bufferp, STOP_SIGNAL) == 0)
                {
                    stop_count++;
                }
                else
                {
                    char *token = strtok(bufferp, " ");

                    while( token != NULL ) 
                    {
                        insert(&root, toUpperCase(token));
                        token = strtok(NULL, " ");
                    }
                }

                free(bufferp);
            }

            
            FILE *fp = fopen(argv[2], "w");

            writeInorder(root, fp);

            fclose(fp);
            
            mq_close(mq);

            mq_unlink(MQNAME);

            gettimeofday(&time2, NULL);

            printf("Total time = %ld miliseconds\n", (time2.tv_usec - time1.tv_usec) );

        }
    }

    return 0;
}

char *toUpperCase(char *str)
{
    char *result = str;
    for (int i = 0; i < strlen(str); i++)
    {
        result[i] = toupper(result[i]);
    }
    return result;
}