Unix Shell in C - Change Directory

Question

I'm another CS beginner working on a simple Shell. At the moment I am trying to change the current directory if an argument is passed, else, report to the current directory.

I tried using chdir() in my program, but it's apparently not working. I tried passing a char* arguments which is tokenized. I also tried with argv[1], but I must be doing something wrong because neither seems to work.

Also, I'm not exactly sure how to make the argument pointer (containing the directory string) static, so that when i use putenv(ARGUMENT HERE) there are no issues.

Here is the pertaining part of my code:

else if (strncmp(command[0], "cd", 2) == 0)
    {
        char *argmnts = strtok(0, " ");

        if (arguments != NULL)
        {
            chdir(argmnts); 
            putenv(argmnts); // THE ARG STRING NEEDS TO BE A STATIC COPY
            getcwd(promptBuff, sizeof(argmnts));
        }
    }

The pointer argmnts points to the tokenized argument part from: char strnBuffer[1000] which has already been tokenized for the command: command[0] = strtok(strnBuffer, " ");

I really appreciate any help/insight.

Thank you.

Answer 1

You probably have a '\n' left over on the end of the input line. Your strtok only recognizes space as separator, so it won't touch the newline. chdir("dir\n") will fail unless you actually have a directory with the newline at the end of its name.