Unix-Shell/sys_cmd.c at master · alpha-warrior/Unix-Shell · GitHub

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#include "headers.h"

void sys_cmd(char * input_str)
{
    long long int i,j,k,cnt,flag_and=0,child_pid,exe_stat,child_child_pid,pid;
    // int status;
    char * command[1000];
    char * arg_list[1000];
    char cmd[1000];


    for(i=0;i<1000;i++)
    {
        arg_list[i] = (char*)malloc(sizeof(char)*1000);
    }

    char * token = strtok(input_str, " ");
    cnt=0;
    while (token!=NULL)
    {
        if(strcmp(token,"&")!=0)
        {
            arg_list[cnt]=token;
            cnt++;
        }
        else
        {
            flag_and=1;
        }
        token = strtok(NULL," ");
    }
    // command = arg_list[0];
    arg_list[cnt] = NULL;

    // for(i=0;i<cnt;i++)
    // {
    //     printf("%s\n",arg_list[i]);
    // }

    child_pid = fork();
    if(child_pid<0)
    {
        perror("ERROR");
        return;
    }

    if(child_pid==0)
    {
        exe_stat = execvp(arg_list[0],arg_list);
        if(exe_stat==-1)
        {
            printf("Please enter a Valid Command\n");
        }
        exit(0);
    }

    if(child_pid>0)
    {
        if(flag_and==0)
        {
            int status;
            foreground_job.pid = child_pid;
            strcpy(foreground_job.command,arg_list[0]);
            foreground_job.id = 0;
            waitpid(child_pid,&status, WUNTRACED);
            foreground_job.pid = -1;
        }
        else
        {
            printf("%s with process pid %lld started\n",arg_list[0],child_pid);
            jobs[job_seq_no].pid = child_pid;
            strcpy(jobs[job_seq_no].command,arg_list[0]);
            jobs[job_seq_no].status = 1;
            jobs[job_seq_no].id = job_seq_no;
            job_seq_no++;
            job_seq_no%=1000;
        }
    }
}