lsof 2>&1 | grep log | awk '/openbox/ { print $10 }' | sed '1d'

# ./cbash2              
Done with main program.
pyro# lsof: WARNING: can't stat() fuse.gvfsd-fuse file system /run/user/1000/gvfs
      Output information may be incomplete.
lsof: status error on 2>&1: No such file or directory
lsof: status error on |: No such file or directory
lsof: status error on grep: No such file or directory
lsof: status error on log: No such file or directory
lsof: status error on |: No such file or directory
lsof: status error on awk: No such file or directory
lsof: status error on '/openbox: No such file or directory
lsof: status error on { print $10 }': No such file or directory
lsof: status error on |: No such file or directory
lsof: status error on sed: No such file or directory
lsof: status error on '1d': No such file or directory
lsof 4.86
 latest revision: ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/
 latest FAQ: ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/FAQ
 latest man page: ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/lsof_man
 usage: [-?abhKlnNoOPRtUvVX] [+|-c c] [+|-d s] [+D D] [+|-f[gG]] [+|-e s]
 [-F [f]] [-g [s]] [-i [i]] [+|-L [l]] [+m [m]] [+|-M] [-o [o]] [-p s]
[+|-r [t]] [-s [p:s]] [-S [t]] [-T [t]] [-u s] [+|-w] [-x [fl]] [--] [names]

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>

// Spawn a child process for the bash part later:
int spawn(char* program, char** arg_list)
{
  pid_t child_pid;

  // Duplicate this process:
  child_pid = fork();
  if (child_pid !=0)
    // This is the parent process.
    return child_pid;
  else {
    // Execute "program" which will call bash:
    execvp (program, arg_list);
    // execvp will only return if an error occurs
    fprintf (stderr, "an error occurred in execvp\n");
    abort();
  }
}

int main()
{
  //Argument list to pass bash commands:
  char* arg_list[] = {
     "lsof",    // argv[0], the name of the program.
     "2>&1",
     "|",
     "grep",
     "log",
     "|",
     "awk",
     "'/openbox/",
     "{ print $10 }'",
     "|",
     "sed",
     "'1d'",
     NULL       // Arg list must end with a null.
  };

  // Spawn the child process running bash.
  spawn("lsof", arg_list);

  printf("Done with main program.\n");

  return 0;
}