hey guys,
ok right now I am trying to enter some input, for example, 'cd'. right now it will get and print the current directory I am in. but when I enter anything, it exits out of my prog. I dont know if my input is being tokenized properly or what. So I am basically just working on the cd input right now. I want it to change my directory but its not doing anything! Also the reason I have my while loop commented out (in main) is because it stays in the infinite loop and doesnt do anything. So I just dont know whats going on! I have been working on this for a week and I just cant get it!
Please help! Thanks!
Code:#include <stdio.h> #include <unistd.h> #include <sys/wait.h> #include <sys/types.h> #include <stdlib.h> #include <signal.h> #include <sys/param.h> #define maxbuf 256 unsigned int pid; //variable to hold id number int status; void signal_handler(int); void parse_string(char [], char *[], int); char arith(char *[]); //------------------------ char arith(char *command[]){ int finalvalue; int temp1; int temp2; if (command[2] == '/') { temp1 = atoi(command[1]); temp2 = atoi(command[3]); if(temp2 == 0) return 0; finalvalue = temp1 / temp2; } else if (command[2] == '*') { temp1 = atoi(command[1]); temp2 = atoi(command[3]); finalvalue = temp1 * temp2; } else if (command[2] == '+'){ temp1 = atoi(command[1]); temp2 = atoi(command[3]); finalvalue = temp1 + temp2; } else if (command[2] == '-'){ temp1 = atoi(command[1]); temp2 = atoi(command[3]); finalvalue = temp1 - temp2; } return finalvalue; } //------------------------ void signal_handler(int sig) //for the ctrl-z part { char *answer[maxbuf]; printf("\n", "The Shell Has Been Locked ", "Please Enter the Password: "); scanf("%s", answer); if (*answer == 'I love operating systems') signal(SIGTSTP, signal_handler); return; } //------------------------ void parse_string(char input_string[], char *command[], int size_buf) { char *token; int i =0; for((token = strtok(input_string, " \n")); token; (token = strtok(NULL, " \n")), i++) { if( i < size_buf - 1) command[i]=token; } command[i] = NULL; return; } //------------------------ int main() { int x = 0; //holds answer from calculations char *buf; //pointer to where the directory is long size; //size of the array, which is the directory name char *dir; //this is the variable that will store the direcory name and then print it out char *path; //this is the array that will hold the changed directory's name char input_string[maxbuf]; //this is the array which will hold the input char *command[maxbuf]; //this is the array which will hold the tokenized input int flag = 1; int pipecount = 0; signal(SIGTSTP, signal_handler); //called when the user hit ctrl-z printf("mysh$>"); if ((buf = (char *)malloc((size_t)size)) != NULL) dir = getcwd(buf, size); //this is the call to get the directory printf("%s >", dir); //will print the directory fgets (input_string, maxbuf, stdin); //this will get the command the user enters parse_string(input_string, command, maxbuf); //this will tokenize the command the user enters //while(command[0] != NULL) { //stays in infinite loop???????? if (command[0] == 'cd'){ dir = chdir(path); printf("%s%", dir); } // else if (command[0] == 'quit') // exit(0); // else if (command[0] == 'dir') // command[0] = "ls"; // else if (command[0] == 'type') // command[0] = "cat"; // else if (command[0] == 'cls') // command[0] = "clear"; // else if (command[0] == 'move') // command[0] = "mv"; // else if (command[0] == 'copy') // command[0] = "cp"; // else if (command[0] == 'del') // command[0] = "rm"; // else if (command[0] == '='){ //x = arith(command); // printf("%s", x); } //else // printf("Bad Command. Please try again."); //} //closes while loop //execvp(command[0], command); //will execute the commands return 0; }
SO I just tried something, and it seems to me that my string isnt even being tokenized......I think thats where the prob is!
Originally Posted by Salem
