execvp , redirecion of output of ls

Question

I am trying to build a shell in C language for OS project. The problem is coming when I am doing redirection part. ls is working fine, but when I do ls > somefile. It gives me an error " ls: cannot access >: No such file or directory ". Here is that part of my code

while(in){
    argv[c]=strdup(in); \\in is output of strtok applied on input string
    in=strtok(NULL,"\n , ");
    c++;
}
argv[c]=NULL;

int rc=fork();
if(rc==0){
    int flag = 0;
    int index = 0;
    int i;
    for(i= 0; i <c;i++)
    {
        if(strcmp(argv[i],">") == 0)
        {
            flag = 1;
            index = i+1;
        }
        if(flag == 1)
        {
            fclose(stdout);
            fopen(argv[index],"w+");
        }
        execvp(argv[0],argv);
     }
else if(rc>0){
    (void) wait(NULL);}
}
return 0;

Answer 1

That error from ls is telling you that you passed > to ls as an argument.

So let us look at your execvp call:

execvp(argv[0],argv);

So you are using the entirety of argv as the arguments to the spawned ls.

Where, in the processing above that call, are you removing the redirection arguments that you've already handled from argv so that ls doesn't see them?

Side note: Are you assuming that that fopen will assign your newly opened file the fd previously used by stdout? That seems like an unwise assumption to me (even if it normally works).

Oh, and your indentation could use some work.