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[unix-history] / usr / src / cmd / su.c

#include <stdio.h>
#include <pwd.h>

struct  passwd *pwd,*getpwnam();
char    *crypt();
char    *getpass();
char    **environ;

main(argc,argv)
int     argc;
char    **argv;
{
       register char **p;
       char *nptr;
       char *password;
       int badsw = 0;
       char *shell = "/bin/sh";

       if(argc > 1)
               nptr = argv[1];
       else
               nptr = "root";
       if((pwd=getpwnam(nptr)) == NULL) {
               printf("Unknown id: %s\n",nptr);
               exit(1);
       }
       if(pwd->pw_passwd[0] == '\0' || getuid() == 0)
               goto ok;
       password = getpass("Password:");
       if(badsw || (strcmp(pwd->pw_passwd, crypt(password, pwd->pw_passwd)) != 0)) {
               printf("Sorry\n");
               exit(2);
       }

ok:
       endpwent();
       setgid(pwd->pw_gid);
       setuid(pwd->pw_uid);
       if (pwd->pw_shell && *pwd->pw_shell)
               shell = pwd->pw_shell;
       for (p=environ; *p; p++) {
               if (strncmp("PS1=", *p, 4) == 0) {
                       *p = "PS1=# ";
                       break;
               }
       }
       execl(shell, "su", 0);
       printf("No shell\n");
       exit(3);
}