C / C++ / MFC

echo xxxxxx | sudo -S ps -A > results

Quote:

PASSWD and NOPASSWD

By default, sudo requires that a user authenticate before running a command. This behavior can be modified via the NOPASSWD tag. Like a Runas_Spec, the NOPASSWD tag sets a default for the commands that follow it in the Cmnd_Spec_List. Conversely, the PASSWD tag can be used to reverse things. For example:

ray rushmore = NOPASSWD: /bin/kill, /bin/ls, /usr/bin/lprm

would allow the user ray to run /bin/kill, /bin/ls, and /usr/bin/lprm as root on the machine “rushmore” without authenticating himself. If we only want ray to be able to run /bin/kill without a password the entry would be:

ray rushmore = NOPASSWD: /bin/kill, PASSWD: /bin/ls, /usr/bin/lprm

system( "echo q | sudo -S ps -A "); //> resultFile");
                           return;

sudo] password for nov25-1:     PID TTY          TIME CMD
      1 ?        00:00:07 systemd
      2 ?        00:00:00 kthreadd
      3 ?        00:00:00 rcu_gp
      4 ?        00:00:00 rcu_par_gp
      5 ?        00:00:00 slub_flushwq
      6 ?        00:00:00 netns
      8 ?        00:00:00 kworker/0:0H-events_highpri
     11 ?        00:00:00 mm_percpu_wq
     12 ?        00:00:00 rcu_tasks_kthread
     13 ?        00:00:00 rcu_tasks_rude_kthread

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

int main ()
{
	int ret;
	ret = system ("echo xxxxxx | sudo -S ps -A >results");
	printf ("ret=%d\n", ret);
	return 0;
}

ps -A >results && cat results

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

int main ()
{
	int ret;
    char line[256];
	ret = system ("echo xxxxxx | sudo -S ps -A >results");
	FILE *f = fopen("results", "r");
    while (!feof(f)) {
        fgets (line, sizeof(line), f);
        puts(line);
    }
    fclose(f);
	return 0;
}

Mircea Neacsu wrote:

You cannot send results to file and console "at the same time"

$ ls | tee /tmp/foo
    PID TTY          TIME CMD
3995778 pts/1    00:00:00 bash
3995865 pts/1    00:00:00 ps
3995866 pts/1    00:00:00 tee
$ cat /tmp/foo
    PID TTY          TIME CMD
3995778 pts/1    00:00:00 bash
3995865 pts/1    00:00:00 ps
3995866 pts/1    00:00:00 tee

k5054 wrote:

I'd like to remind you of the tee command

Salvatore Terress wrote:

obviously Qt question

C++ "sudo" provide password

[k5054@localhost]$ sudo ps
[sudo] password for k5054: 
sudo: no password was provided
sudo: a password is required
[k5054@localhost]$ cat example.cpp
 #include <iostream>
 #include <cstdio>
 #include <cstdlib>

int main()
{
    std::string userPass{"myPassword"};
    std::string command{"sudo -S ps -lf 2>/dev/null <<_EOF\n" + userPass + "\n_EOF"};
    FILE *pipe = popen(command.c_str(), "r");
    char *line = NULL;
    size_t len = 0;
    ssize_t rlen;
    while( (rlen = getline(&line, &len, pipe))  > 0) {
        line[--rlen] = '\0'; // trim trailing newline
        std::cout << line << '\n';
    }

    pclose(pipe);
    free(line);

}
[k5054@localhost]$ make example
g++ -Wall -Wextra -ggdb    example.cpp   -o example
[k5054@localhost]$ ./example 
F S UID          PID    PPID  C PRI  NI ADDR SZ WCHAN  STIME TTY          TIME CMD
1 S root        4030    4029  0  80   0 -  4799 do_pol 11:49 pts/2    00:00:00 sudo -S ps -lf
4 R root        4031    4030  0  80   0 -  3502 -      11:49 pts/2    00:00:00 ps -lf
[k5054@localhost]$