🚀 go-pugleaf

Hi,
	I noticed that a few people have asked for this code over the
years.  So, below is a short snippet that will check to see if a given
user is at the console.  Just compile it, and then run it, and then
type in the users name.  It probably isn't the most elegant way to do
it, but it works.


#include <stdio.h>
#include <utmp.h>
 
#define		ATCONSOLE	1
#define		FAILED		2
#define		NOTATCONSOLE	3
 
#define		MAXNAME		12
 
find_user(char *name)
{
  struct utmp ubuf;
  FILE *fd;
 
  if ((fd = fopen("/etc/utmp", "r")) == NULL) {
    perror("Can't open /etc/utmp");
    return (FAILED);
  }
  while (fread((char *) &ubuf, sizeof ubuf, 1, fd) == 1) {
    if(strncmp(ubuf.ut_name, name, sizeof(ubuf.ut_name)) == 0 &&
       strcmp(ubuf.ut_line, "console") == 0)
      return ATCONSOLE;
  }
  return NOTATCONSOLE;
}
 
main() {
  char *loginName;
  loginName = (char *)malloc(sizeof(char) * MAXNAME);
  scanf("%s", loginName);
  if(find_user(loginName) == ATCONSOLE)
    printf("%s is at the console.\n", loginName);
  else
    printf("%s is not at the console.\n");
}
-- 

		-Scott Violet (xepo@csd4.csd.uwm.edu)