how to use this in terminal:

Question

I got a moddified ls:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int main(int argc, char **argv){
    char command[50];
    strcpy(command,"/bin/ls ");
    gid_t egid = getegid();
    setregid(egid, egid);
    if(argc > 1) {
        if(strlen(argv[1]) > 40) {
            printf("The command you have given is too long, try again.\n");
            return 0;
        }
        strcat(command,argv[1]);
        system(command);
    }else{
        printf("This is a special NSA-modified 'ls' program. See 'man ls' for further details on how to use it.\n");
        printf("USAGE: %s [flags & files]\n",argv[0]);
    }
    return 0;
}

i have to execute a program called get-code but i don't have the privileges to execute it without the ls(the modified ls is in the same directory as the get-code program), so how can i fool the system() to execute the get-code using the modified ls?

Answer 1

The key is this line: strcat(command,argv[1]); How can you make it so command does more than just ls?

To execute multiple commands on the same line, you can separate them with the ; character. So echo "hello"; echo "world" echo "hello"; echo "world" will have the shell execute both of those commands, one after the other. Knowing that, how can you make system(command); execute get-code after ls ?