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GETPWENT(3) BSD Library Functions Manual GETPWENT(3) NAME endpwent, getpwent, getpwnam, getpwnam_r, getpwuid, getpwuid_r, setpassent, setpwent -- password database operations LIBRARY Standard C Library (libc, -lc) SYNOPSIS #include <pwd.h> void endpwent(void); struct passwd * getpwent(void); struct passwd * getpwnam(const char *login); int getpwnam_r(const char *login, struct passwd *pwd, char *buffer, size_t bufsize, struct passwd **result); struct passwd * getpwuid(uid_t uid); int getuid_r(uid_t uid, struct passwd *pwd, char *buffer, size_t bufsize, struct passwd **result); int setpassent(int stayopen); void setpwent(void); DESCRIPTION These functions operate on the password database file, which is described in passwd(5). Each entry in the database is defined by the structure passwd, found in the include file <pwd.h>: struct passwd { char *pw_name; /* user name */ char *pw_passwd; /* encrypted password */ uid_t pw_uid; /* user uid */ gid_t pw_gid; /* user gid */ time_t pw_change; /* password change time */ char *pw_class; /* user access class */ char *pw_gecos; /* Honeywell login info */ char *pw_dir; /* home directory */ char *pw_shell; /* default shell */ time_t pw_expire; /* account expiration */ int pw_fields; /* internal: fields filled in */ }; The functions getpwnam() and getpwuid() search the password database for the given login name or user uid, respectively, always returning the first one encountered. All of these routines are thread-safe. The getpwent(), getpwnam(), and getpwuid() routines return a pointer to a result managed by the system library in a thread-specific data structure. Every thread has space for a pointer to a struct passwd and allocates its own storage for the result. Neither previously returned values in memory nor a previously returned pointer value should be used by a thread after calling any one of these three routines. Memory allocated by a thread is automatically released on subsequent calls by the same thread to any of these three routines, and when the thread exits. The functions getpwnam_r() and getpwuid_r() take additional arguments which supply storage space for the returned result. The pwd parameter is a pointer to a struct passwd, which must be allocated by the caller. The buffer parameter is a pointer to a block of memory with a size specified by bufsize. This buffer is used to hold the values which are pointed to by values filled in the pwd structure. Zero is returned on success. If insufficient memory is supplied, these routines return ERANGE. The getpwent() function sequentially reads the password database and is intended for programs that wish to process the complete list of users. The setpassent() function accomplishes two purposes. First, it causes getpwent() to ``rewind'' to the beginning of the database. Additionally, if stayopen is non-zero, file descriptors are left open, significantly speeding up subsequent accesses for all of the routines. (This latter functionality is unnecessary for getpwent(), as it doesn't close its file descriptors by default.) It is dangerous for long-running programs to keep the file descriptors open, as the database will become out of date if it is updated while the program is running. The setpwent() function is identical to setpassent() with an argument of zero, save that it does not return a status value. The endpwent() function closes any open files. As of Mac OS X 10.3, there are now different per-user behaviours of this function, based on the AuthenticationAuthority value stored for the queried user in DirectoryServices. If the queried user is still a legacy crypt password user or now has an AuthenticationAuthority value containing ``;basic;'', these routines will behave in their standard BSD fashion. These functions will ``shadow'' the password file, e.g. allow only certain programs to have access to the encrypted password. If the process which calls them has an effective uid of 0, the encrypted password will be returned, otherwise, the password field of the returned structure will point to the string `*'. By default in Mac OS X 10.3 and later all users will have an Authentica-tionAuthority AuthenticationAuthority tionAuthority with the value ``;ShadowHash;''. These users will have a visible password value of ``********''. These functions will have no access to the encrypted password whatsoever. Setting or changing an user password must be done entirely through the DirectoryService APIs for this default user. There also exists an ``Apple Password Server'' user whose password value is also ``********'' and with an AuthenticationAuthority that contains the value ";ApplePasswordServer;" among other data. There is no getpwnam access to the password for this user either and again set/change password can be done through the DirectoryService API. Finally in support of local user caching there is a local cached user whose password is also ``********'' and has an AuthenticationAuthority value containing ``;LocalCachedUser;'' among other data. These functions also provide no access to the password for this user and set/change pass-word password word functionality is through the DirectoryService API. RETURN VALUES The functions getpwent(), getpwnam(), and getpwuid() return a valid pointer to a passwd structure on success and a null pointer if end-of-file end-offile file is reached or an error occurs. The setpassent() function returns 0 on failure and 1 on success. The endpwent() and setpwent() functions have no return value. FILES /etc/pwd.db The insecure password database file /etc/spwd.db The secure password database file /etc/master.passwd The current password file /etc/passwd A Version 7 format password file LEGACY SYNOPSIS #include <sys/types.h> #include <pwd.h> The include file <sys/types.h> is necessary for the getpwent, getpwnam, and getpwuid functions. int setpwent(void); The setpwent() function returns 0 on failure and 1 on success. SEE ALSO getlogin(2), getgrent(3), yp(8), passwd(5), pwd_mkdb(8), vipw(8) HISTORY The getpwent(), getpwnam(), getpwuid(), setpwent(), and endpwent() func-tions functions tions appeared in Version 7 AT&T UNIX. The setpassent() function appeared in 4.3BSD-Reno. COMPATIBILITY The historic function setpwfile(3), which allowed the specification of alternate password databases, has been deprecated and is no longer avail-able. available. able. BUGS The functions getpwent(), getpwnam(), and getpwuid() leave their results in internal thread-specific memory and return a pointer to that object. Subsequent calls to any of these three routines by the same thread will release the object and return a new pointer value. BSD September 20, 1994 BSD |