cd.c

#include "headers.h"

int cd()
{
    char *path = malloc(PATH_MAX);
    char *pathcpy = malloc(PATH_MAX);
    static char *previous_directory = shell_path;
    char *arg = malloc(4096);
    //get current path 
    if (getcwd(path, PATH_MAX) == 0)
    {
        perror("getcwd");
        return 1;
    }
    //make a copy
    strcpy(pathcpy, path);

    //case when too many arguments
    if (arglength > 2)
    {
        printf("Error:cd too many argument\n");
        free(path);
        return 1;
    }

    //no argument given then switch to home directory
    if (arglength == 1)
    {
        strcpy(arg, "~");
    }
    else
    {
        //change to current directory only
        strcpy(arg, arguments[1]);
    }
    if (strcmp(arg,".")==0)
    {   
        free(path);
        return 0;
    }

    //switch to home directory
    else if (strcmp(arg, "~") == 0)
    {
        if (chdir(shell_path) == -1)
        {
            perror("chdir");
            free(path);
            return 1;
        }
    }
    //switch to previous directory and print
    else if (strcmp(arg, "-") == 0)
    {
        printf("%s\n", previous_directory);
        if (chdir(previous_directory) == -1)
        {
            perror("chdir");
            free(path);
            return 1;
        }
    }
    else
    { // change to directory token
        //manages .. too
        if (chdir(arg) == -1)
        {
            perror("chdir");
            free(path);
            return -1;
        }
    }
    //retain previous directory path for future use
    previous_directory = pathcpy;
    free(path);
    return 0;
}