Seth Woolley's Man Viewer

SHADOW(3)                                                            SHADOW(3)



NAME
       shadow(3,5) - encrypted password file(1,n) routines

SYNTAX
       #include <shadow.h>


       struct spwd *getspent();


       struct spwd *getspnam(char  *name);


       void setspent();


       void endspent();


       struct spwd *fgetspent(FILE  *fp);


       struct spwd *sgetspent(char  *cp);


       int putspent(struct spwd  *p,  FILE  *fp);


       int lckpwdf();


       int ulckpwdf();


DESCRIPTION
       shadow(3,5)   manipulates   the   contents  of  the  shadow(3,5)  password  file(1,n),
       /etc/shadow(3,5). The structure in(1,8) the #include file(1,n) is:

       struct spwd {
             char               *sp_namp; /* user login(1,3,5) name */
             char               *sp_pwdp; /* encrypted password */
             long int      sp_lstchg; /* last password change */
             long int      sp_min; /* days until change allowed. */
             long int      sp_max; /* days before change required */
             long int      sp_warn; /* days warning for expiration */
             long int      sp_inact; /* days before account inactive */
             long int      sp_expire; /* date when account expires */
             unsigned long int  sp_flag; /* reserved for future use */
       }



       The meanings of each field are:


         sp_namp - pointer to null-terminated user name

         sp_pwdp - pointer to null-terminated password

         sp_lstchg - days since Jan 1, 1970 password was last changed

         sp_min - days before which password may not be changed

         sp_max - days after which password must be changed

         sp_warn - days before password is to expire that user is  warned  of
          pending password expiration

         sp_inact  -  days  after password expires that account is considered
          inactive and disabled

         sp_expire - days since Jan 1, 1970 when account will be disabled

         sp_flag - reserved for future use



DESCRIPTION
       getspent, getspname  fgetspent, and sgetspent each return a pointer  to
       a struct spwd. getspent returns the next entry from the file(1,n), and fget-
       spent returns the next entry from the given stream, which is assumed to
       be a file(1,n) of the proper format. sgetspent returns a pointer to a struct
       spwd using the provided string(3,n) as input.  getspnam  searches  from  the
       current position in(1,8) the file(1,n) for an entry matching name.


       setspent  and  endspent  may  be  used  to begin and end, respectively,
       access(2,5) to the shadow(3,5) password file.


       The lckpwdf and ulckpwdf routines should be used  to  insure  exclusive
       access(2,5)  to  the  /etc/shadow(3,5)  file.  lckpwdf attempts to acquire a lock
       using pw_lock for up to 15  seconds.  It  continues  by  attempting  to
       acquire  a  second lock using spw_lock for the remainder of the initial
       15 seconds. Should either attempt fail after a  total  of  15  seconds,
       lckpwdf returns -1. When both locks are acquired 0 is returned.


DIAGNOSTICS
       Routines  return  NULL  if(3,n) no more entries are available or if(3,n) an error(8,n)
       occurs during processing. Routines which have int as the  return  value
       return 0 for success and -1 for failure.


CAVEATS
       These  routines  may  only  be  used by the super user as access(2,5) to the
       shadow(3,5) password file(1,n) is restricted.


FILES
       /etc/shadow(3,5)
              secure user account information

SEE ALSO
       getpwent(3), shadow(3,5)(5)


AUTHOR
       Julianne Frances Haugh (jockgrrl@ix.netcom.com)




                                                                     SHADOW(3)