# getspnam

## NAME



           getspnam, getspnam_r, getspent, getspent_r, setspent, endspent,
           fgetspent, fgetspent_r, sgetspent, sgetspent_r, putspent, lckpwdf,
           ulckpwdf - get shadow password file entry
    


## LIBRARY



           Standard C library (_libc_ , _-lc_)
    


## SYNOPSIS



           /* General shadow password file API */
           **#include <shadow.h>**
    
           **struct spwd *getspnam(const char ***_name_**);**
           **struct spwd *getspent(void);**
    
           **void setspent(void);**
           **void endspent(void);**
    
           **struct spwd *fgetspent(FILE ***_stream_**);**
           **struct spwd *sgetspent(const char ***_s_**);**
    
           **int putspent(const struct spwd ***_p_**, FILE ***_stream_**);**
    
           **int lckpwdf(void);**
           **int ulckpwdf(void);**
    
           /* GNU extension */
           **#include <shadow.h>**
    
           **int getspent_r(** size_t size;
                          **struct spwd ***_spbuf_**,**
                          **char** _buf_**[**_size_**], size_t** _size_**, struct spwd ****_spbufp_**);**
           **int getspnam_r(** size_t size;
                          **const char ***_name_**, struct spwd ***_spbuf_**,**
                          **char** _buf_**[**_size_**], size_t** _size_**, struct spwd ****_spbufp_**);**
    
           **int fgetspent_r(** size_t size;
                          **FILE ***_stream_**, struct spwd ***_spbuf_**,**
                          **char** _buf_**[**_size_**], size_t** _size_**, struct spwd ****_spbufp_**);**
           **int sgetspent_r(** size_t size;
                          **const char ***_s_**, struct spwd ***_spbuf_**,**
                          **char** _buf_**[**_size_**], size_t** _size_**, struct spwd ****_spbufp_**);**
    
       Feature Test Macro Requirements for glibc (see
       feature_test_macros(7)):
    
           **getspent_r**(), **getspnam_r**(), **fgetspent_r**(), **sgetspent_r**():
               Since glibc 2.19:
                   _DEFAULT_SOURCE
               glibc 2.19 and earlier:
                   _BSD_SOURCE || _SVID_SOURCE
    


## DESCRIPTION



           Long ago it was considered safe to have encrypted passwords openly
           visible in the password file.  When computers got faster and
           people got more security-conscious, this was no longer acceptable.
           Julianne Frances Haugh implemented the shadow password suite that
           keeps the encrypted passwords in the shadow password database
           (e.g., the local shadow password file _/etc/shadow_ , NIS, and LDAP),
           readable only by root.
    
           The functions described below resemble those for the traditional
           password database (e.g., see getpwnam(3) and getpwent(3)).
    
           The **getspnam**() function returns a pointer to a structure
           containing the broken-out fields of the record in the shadow
           password database that matches the username _name_.
    
           The **getspent**() function returns a pointer to the next entry in the
           shadow password database.  The position in the input stream is
           initialized by **setspent**().  When done reading, the program may
           call **endspent**() so that resources can be deallocated.
    
           The **fgetspent**() function is similar to **getspent**() but uses the
           supplied stream instead of the one implicitly opened by
           **setspent**().
    
           The **sgetspent**() function parses the supplied string _s_ into a
           struct _spwd_.
    
           The **putspent**() function writes the contents of the supplied struct
           _spwd *p_ as a text line in the shadow password file format to
           _stream_.  String entries with value NULL and numerical entries with
           value -1 are written as an empty string.
    
           The **lckpwdf**() function is intended to protect against multiple
           simultaneous accesses of the shadow password database.  It tries
           to acquire a lock, and returns 0 on success, or -1 on failure
           (lock not obtained within 15 seconds).  The **ulckpwdf**() function
           releases the lock again.  Note that there is no protection against
           direct access of the shadow password file.  Only programs that use
           **lckpwdf**() will notice the lock.
    
           These were the functions that formed the original shadow API.
           They are widely available.
    
       **Reentrant versions**
           Analogous to the reentrant functions for the password database,
           glibc also has reentrant functions for the shadow password
           database.  The **getspnam_r**() function is like **getspnam**() but stores
           the retrieved shadow password structure in the space pointed to by
           _spbuf_.  This shadow password structure contains pointers to
           strings, and these strings are stored in the buffer _buf_ of size
           _size_.  A pointer to the result (in case of success) or NULL (in
           case no entry was found or an error occurred) is stored in
           _*spbufp_.
    
           The functions **getspent_r**(), **fgetspent_r**(), and **sgetspent_r**() are
           similarly analogous to their nonreentrant counterparts.
    
           Some non-glibc systems also have functions with these names, often
           with different prototypes.
    
       **Structure**
           The shadow password structure is defined in _< shadow.h>_ as follows:
    
               struct spwd {
                   char *sp_namp;     /* Login name */
                   char *sp_pwdp;     /* Encrypted password */
                   long  sp_lstchg;   /* Date of last change
                                         (measured in days since
                                         1970-01-01 00:00:00 +0000 (UTC)) */
                   long  sp_min;      /* Min # of days between changes */
                   long  sp_max;      /* Max # of days between changes */
                   long  sp_warn;     /* # of days before password expires
                                         to warn user to change it */
                   long  sp_inact;    /* # of days after password expires
                                         until account is disabled */
                   long  sp_expire;   /* Date when account expires
                                         (measured in days since
                                         1970-01-01 00:00:00 +0000 (UTC)) */
                   unsigned long sp_flag;  /* Reserved */
               };
    


## RETURN VALUE



           The functions that return a pointer return NULL if no more entries
           are available or if an error occurs during processing.  The
           functions which have _int_ as the return value return 0 for success
           and -1 for failure, with _errno_ set to indicate the error.
    
           For the nonreentrant functions, the return value may point to
           static area, and may be overwritten by subsequent calls to these
           functions.
    
           The reentrant functions return zero on success.  In case of error,
           an error number is returned.
    


## ERRORS



           **EACCES** The caller does not have permission to access the shadow
                  password file.
    
           **ERANGE** Supplied buffer is too small.
    


## FILES



           _/etc/shadow_
                  local shadow password database file
    
           _/etc/.pwd.lock_
                  lock file
    
           The include file _< paths.h>_ defines the constant **_PATH_SHADOW** to
           the pathname of the shadow password file.
    


## ATTRIBUTES



           For an explanation of the terms used in this section, see
           attributes(7).
           ┌───────────────┬───────────────┬────────────────────────────────┐
           │ **Interface** │ **Attribute** │ **Value** │
           ├───────────────┼───────────────┼────────────────────────────────┤
           │ **getspnam**()    │ Thread safety │ MT-Unsafe race:getspnam locale │
           ├───────────────┼───────────────┼────────────────────────────────┤
           │ **getspent**()    │ Thread safety │ MT-Unsafe race:getspent        │
           │               │               │ race:spentbuf locale           │
           ├───────────────┼───────────────┼────────────────────────────────┤
           │ **setspent**(),   │ Thread safety │ MT-Unsafe race:getspent locale │
           │ **endspent**(),   │               │                                │
           │ **getspent_r**()  │               │                                │
           ├───────────────┼───────────────┼────────────────────────────────┤
           │ **fgetspent**()   │ Thread safety │ MT-Unsafe race:fgetspent       │
           ├───────────────┼───────────────┼────────────────────────────────┤
           │ **sgetspent**()   │ Thread safety │ MT-Unsafe race:sgetspent       │
           ├───────────────┼───────────────┼────────────────────────────────┤
           │ **putspent**(),   │ Thread safety │ MT-Safe locale                 │
           │ **getspnam_r**(), │               │                                │
           │ **sgetspent_r**() │               │                                │
           ├───────────────┼───────────────┼────────────────────────────────┤
           │ **lckpwdf**(),    │ Thread safety │ MT-Safe                        │
           │ **ulckpwdf**(),   │               │                                │
           │ **fgetspent_r**() │               │                                │
           └───────────────┴───────────────┴────────────────────────────────┘
    
           In the above table, _getspent_ in _race:getspent_ signifies that if
           any of the functions **setspent**(), **getspent**(), **getspent_r**(), or
           **endspent**() are used in parallel in different threads of a program,
           then data races could occur.
    


## VERSIONS



           Many other systems provide a similar API.
    


## STANDARDS



           None.
    


* * *