Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
getspnam(3C)		 Standard C Library Functions		  getspnam(3C)

NAME
       getspnam,  getspnam_r,  getspent, getspent_r, setspent, endspent, fget-
       spent, fgetspent_r - get	password entry

SYNOPSIS
       #include	<shadow.h>

       struct spwd *getspnam(const char	*name);

       struct spwd *getspnam_r(const char *name,  struct  spwd	*result,  char
       *buffer,	int buflen);

       struct spwd *getspent(void);

       struct spwd *getspent_r(struct spwd *result, char *buffer, int buflen);

       void setspent(void);

       void endspent(void);

       struct spwd *fgetspent(FILE *fp);

       struct  spwd  *fgetspent_r(FILE *fp, struct spwd	*result, char *buffer,
       int buflen);

DESCRIPTION
       These functions are used	to obtain shadow password entries.   An	 entry
       may  come from any of the sources for shadow specified in the /etc/nss-
       witch.conf file (see nsswitch.conf(4)).

       The getspnam() function searches	for a shadow password entry  with  the
       login name specified by the character string argument name.

       The   setspent(), getspent(), and endspent() functions are used to enu-
       merate shadow password entries from the database.

       The setspent() function sets (or	resets)	the enumeration	to the	begin-
       ning  of	 the  set of shadow password entries.  This function should be
       called before the first call to getspent(). Calls to  getspnam()	 leave
       the enumeration position	in an indeterminate state.

       Successive  calls  to  getspent()  return  either successive entries or
       NULL, indicating	the end	of the enumeration.

       The endspent() function may be called to	indicate that the  caller  ex-
       pects to	do no further shadow password retrieval	operations; the	system
       may then	 close the shadow password file, deallocate resources  it  was
       using, and so forth.  It	is still allowed, but possibly less efficient,
       for the process to call more shadow password  functions	after  calling
       endspent().

       The  fgetspent()	 function,  unlike the other functions above, does not
       use nsswitch.conf; it reads and parses the next line  from  the	stream
       fp,  which  is  assumed	to  have  the  format  of the shadow file (see
       shadow(4)).

   Reentrant Interfaces
       The  getspnam(),	getspent(), and	fgetspent() functions use static stor-
       age  that is re-used in each call, making these routines	unsafe for use
       in multithreaded	applications.

       The  getspnam_r(), getspent_r(),	and  fgetspent_r()  functions  provide
       reentrant interfaces for	these operations.

       Each  reentrant	interface performs the same operation as its non-reen-
       trant counterpart, named	by removing the	 _r suffix.  The reentrant in-
       terfaces, however, use buffers supplied by the caller to	store returned
       results,	and  are safe for  use	in  both  single-threaded  and	multi-
       threaded	applications.

       Each  reentrant	interface takes	the same argument as its non-reentrant
       counterpart, as well as the following additional	arguments.  The	result
       argument	 must be a pointer to a	struct spwd structure allocated	by the
       caller.	On successful completion,  the	function  returns  the	shadow
       password	 entry	in  this  structure.  The   buffer  argument must be a
       pointer to a buffer supplied by the caller.  This  buffer  is  used  as
       storage space for the shadow password data.  All	of the pointers	within
       the returned struct spwd	result point to	data stored within this	buffer
       (see RETURN VALUES). The	buffer must be large enough to hold all	of the
       data associated with the	shadow password	 entry.	 The  buflen  argument
       should give the size in bytes of	the buffer indicated by	buffer.

       For  enumeration	in multithreaded applications, the position within the
       enumeration is a	process-wide property shared by	all threads. The  set-
       spent()	function may be	used in	a multithreaded	application but	resets
       the enumeration position	for all	threads.  If multiple  threads	inter-
       leave  calls  to	getspent_r(), the threads will enumerate disjoint sub-
       sets of the shadow password database.

       Like its	non-reentrant counterpart, getspnam_r()	leaves the enumeration
       position	in an indeterminate state.

RETURN VALUES
       Password	 entries  are represented by the struct	spwd structure defined
       in <shadow.h>:

       struct spwd{
	   char		   *sp_namp;	 /* login name */
	   char		   *sp_pwdp;	 /* encrypted passwd */
	   long		   sp_lstchg;	 /* date of last change	*/
	   long		   sp_min;	 /* min	days to	passwd change */
	   long		   sp_max;	 /* max	days to	passwd change*/
	   long		   sp_warn;	 /* warning period */
	   long		   sp_inact;	 /* max	days inactive */
	   long		   sp_expire;	 /* account expiry date	*/
	   unsigned long   sp_flag;	 /* not	used */
       };

       See shadow(4) for more information on the interpretation	of this	data.

       The  getspnam()and getspnam_r() functions each return a	pointer	 to  a
       struct  spwd if they successfully locate	the requested entry; otherwise
       they return NULL.

       The  getspent(),	getspent_r(), fgetspent(), and	fgetspent()  functions
       each  return  a pointer to a struct spwd	if they	successfully enumerate
       an entry; otherwise they	return NULL, indicating	the end	of the enumer-
       ation.

       The  getspnam(),	getspent(), and	fgetspent() functions use static stor-
       age, so returned	data must be copied before a subsequent	call to	any of
       these functions if the data is to be saved.

       When the	pointer	returned by the	reentrant functions getspnam_r(), get-
       spent_r(), and fgetspent_r() is non-null, it is always equal to the re-
       sult pointer that was supplied by the caller.

ERRORS
       The  reentrant functions	 getspnam_r(), getspent_r(), and fgetspent_r()
       will return NULL	and set	errno to ERANGE	if the length  of  the	buffer
       supplied	 by  caller  is	not large enough to store the result.  See in-
       tro(2) for the proper usage  and	 interpretation	 of  errno  in	multi-
       threaded	applications.

USAGE
       Applications that use the interfaces described on this manual page can-
       not be linked statically, since the implementations of these  functions
       employ dynamic loading and linking of shared objects at run time.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |See  "Reentrant Interfaces"  |
       |			     |in DESCRIPTION.		   |
       +-----------------------------+-----------------------------+

SEE ALSO
       nispasswd(1), passwd(1),	yppasswd(1),  intro(3)	getlogin(3C),	getpw-
       nam(3C),	nsswitch.conf(4), passwd(4), shadow(4),	attributes(5)

WARNINGS
       The  reentrant interfaces getspnam_r(), getspent_r(), and fgetspent_r()
       are included in this release on an uncommitted basis only, and are sub-
       ject to change or removal in future minor releases.

NOTES
       When  compiling multithreaded applications, see intro(3), Notes On Mul-
       tithreaded Applications,	for information	about the use  of  the	_REEN-
       TRANT flag.

       Use  of	the  enumeration interfaces getspent() and getspent_r()	is not
       recommended; enumeration	is supported for the  shadow  file,  NIS,  and
       NIS+,  but in general is	not efficient and may not be supported for all
       database	sources.  The semantics	of enumeration are  discussed  further
       in nsswitch.conf(4).

       Access to shadow	password information may be restricted in a manner de-
       pending on the database source being used.  Access to  the  /etc/shadow
       file  is	 generally  restricted	to processes running as	the super-user
       (root).	Other database sources may impose stronger or  less  stringent
       restrictions.

       When  NIS  is  used  as	the  database source,  the information for the
       shadow password entries is obtained  from  the  ``passwd.byname''  map.
       This map	stores only the	information for	the sp_namp and	sp_pwdp	fields
       of the struct spwd structure.  Shadow password  entries	obtained  from
       NIS will	contain	the value -1 in	the remainder of the fields.

       When NIS+ is used as the	database source, and the caller	lacks the per-
       mission needed  to  retrieve  the  encrypted  password  from  the  NIS+
       ``passwd.org_dir''  table, the NIS+ service returns the string ``*NP*''
       instead of the actual encrypted password	 string.   The	functions  de-
       scribed on this page will then return the string	``*NP*'' to the	caller
       as the value of the member sp_pwdp  in  the  returned  shadow  password
       structure.

SunOS 5.9			  29 Dec 1996			  getspnam(3C)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | USAGE | ATTRIBUTES | SEE ALSO | WARNINGS | NOTES

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=fgetspent&sektion=3c&manpath=SunOS+5.9>

home | help