jcshell-terminal.c

/*
*****************************************************************************
    OPERATING SYSTEMS PROJECT (COMPUTER SCIENCE - 2nd YEAR)
*****************************************************************************
        PROJECT:				JCShell
        NAME:               	jcshell-terminal
        DEVELOPED BY:			GROUP Nº02 (DEI-CC/FC/UAN 2020)
        WRITTEN IN:         	C Language
        FOR:               		UNIX
        STABLE VERSION:     	V.2.5
        TEACHER:            	Msc. JOÃO COSTA
        YEAR:                	13/06/2021 - 06/07/2021
*****************************************************************************
       AGOSTINHO NETO UNIVERSITY
       FACULTY OF SCIENCES
       DEPARTMENT OF COMPUTER SCIENCES

        GROUP Nº02:
                - ELIÚDE PATRÍCIO DE CARVALHO VEMBA - (ID Github) HelioPC
                - LUDMILO HUEBA CAMBAMBI - (ID Github) Ludmilo-cambambi
                - PEDRO MANUEL DOMINGOS - (ID Github) pedro7-7-7
                - LUCÍLIO TÉRCIO GOMES - (ID Github) luciliogomez
*****************************************************************************
*/

#include <stdio.h>
#include <fcntl.h>
#define __USE_POSIX 1
#define __USE_XOPEN_EXTENDED
#include <signal.h>
#include <sys/stat.h>
#include "headers/commandlinereader.h"
#define __CONST__
#define __FILE_PIPE__
#include "headers/ourheadfile.h"

extern int errno;

void sighandler(int);

int exit_, fd;
char stats_pipe[30];
struct sigaction sact;

int main(int argc, char **argv)
{
    int fd_aux, fdin;
    char buffer[BUFFERSIZE];

    if (argc != 2)
    {
        errno = EINVAL;
        perror("\033[31mjcshell-terminal only takes 1 args:\033[m ./jcshell-"
               "terminal \'PIPE TO JCSHELL\'");
        exit(EINVAL);
    }

    if (strcmp(argv[1], NAMED_PIPE) != 0)
    {
        errno = EINVAL;
        perror("\033[31mArgument must be named pipe \"jcshell-in\"");
        exit(EINVAL);
    }

    CLEAR();

    printf("\t\t%sJCSHELL-TERMINAL %s%s\n", PURPLE, VERSION_TERM, NORM);

    if (access(NAMED_PIPE, F_OK) == -1)
    {
        errno = ENOENT;
        perror("\033[31mNamed pipe \"jcshell-in\" not found");
        exit(ENOENT);
    }

    if ((fd = open(NAMED_PIPE, O_WRONLY, S_IWUSR)) < 0)
    {
        perror("\033[31mCouldn\'t open named pipe \"jcshell-in\"");
        exit(errno);
    }

    if (access(NAMED_PIPE_REG, F_OK) == -1)
    {
        errno = ENOENT;
        perror("\033[31mNamed pipe \"reg-in\" not found");
        exit(ENOENT);
    }

    if ((fd_aux = open(NAMED_PIPE_REG, O_WRONLY, S_IWUSR)) < 0)
    {
        perror("\033[31mCouldn\'t open named pipe \"jcshell-in\"");
        exit(errno);
    }

    exit_ = 0;

    sact.sa_handler = sighandler;
    sigemptyset(&sact.sa_mask);
    sact.sa_flags = 0;

    sigaction(SIGTERM, &sact, NULL);

    sprintf(buffer, "%d", (int)getpid());

    write(fd_aux, buffer, strlen(buffer));

    close(fd_aux);

    strcpy(stats_pipe, NAMED_PIPE_AUX);
    strcat(stats_pipe, buffer);

    if (mkfifo(stats_pipe, S_IRWXU | S_IRWXG | S_IRWXO) < 0)
    {
        perror("\033[31mError creating auxiliary FIFO.");
        exit(errno);
    }

    while (1)
    {
        if (!exit_)
            printf("%s$%s ", BLUE, GREEN);
        /* Read the command */
        if (fgets(buffer, BUFFERSIZE, stdin) == NULL)
            continue;

        printf("\n%s\n", buffer);
        fflush(stdin);

        if (feof(stdin) != 0)
            strcpy(buffer, "exit");

        if (strstr(buffer, "exit"))
            exit_ = 1;

        if (strcmp(buffer, "exit\n") == 0)
        {
            sprintf(buffer, "exit-%d\n", (int)getpid());
            write(fd, buffer, strlen(buffer));
        }

        else if (!strcmp(buffer, "stats\n"))
        {
            write(fd, stats_pipe, strlen(stats_pipe));

            if ((fdin = open(stats_pipe, O_RDONLY, S_IRUSR | S_IWUSR)) < 0)
            {
                perror("\033[31mCouldn\'t open stats pipe");
                exit(errno);
            }

            strdel(buffer);

            while (read(fdin, buffer, BUFFERSIZE) > 0)
                printf("%s", buffer);

            close(fdin);
        }

        else
            write(fd, buffer, strlen(buffer));
    }
}

void sighandler(int sig)
{
    exit_ = sig;
    unlink(stats_pipe);
    close(fd);
    exit(EXIT_SUCCESS);
}