GETPWENT(3) GETPWENT(3) NAME getpwent, getpwuid, getpwnam, setpwent, endpwent, setpwfile - get pass‐ word file entry SYNOPSIS #include struct passwd *getpwuid(uid) int uid; struct passwd *getpwnam(name) char *name; struct passwd *getpwent() setpwent() endpwent() setpwfile(name) char *name; DESCRIPTION _G_e_t_p_w_e_n_t_, _g_e_t_p_w_u_i_d and _g_e_t_p_w_n_a_m each return a pointer to an object with the following structure containing the broken-out fields of a line in the password file. /* Copyright (C) 1991,1992,1995-2001,2003,2004 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ /* * POSIX Standard: 9.2.2 User Database Access */ #ifndef _PWD_H #define _PWD_H 1 #include __BEGIN_DECLS #include #define __need_size_t #include #if defined __USE_XOPEN || defined __USE_XOPEN2K /* The Single Unix specification says that some more types are available here. */ # ifndef __gid_t_defined typedef __gid_t gid_t; # define __gid_t_defined # endif # ifndef __uid_t_defined typedef __uid_t uid_t; # define __uid_t_defined # endif #endif /* The passwd structure. */ struct passwd { char *pw_name; /* Username. */ char *pw_passwd; /* Password. */ __uid_t pw_uid; /* User ID. */ __gid_t pw_gid; /* Group ID. */ char *pw_gecos; /* Real name. */ char *pw_dir; /* Home directory. */ char *pw_shell; /* Shell program. */ }; #if defined __USE_SVID || defined __USE_GNU # define __need_FILE # include #endif #if defined __USE_SVID || defined __USE_MISC || defined __USE_XOPEN_EXTENDED /* Rewind the password-file stream. This function is a possible cancellation point and therefore not marked with __THROW. */ extern void setpwent (void); /* Close the password-file stream. This function is a possible cancellation point and therefore not marked with __THROW. */ extern void endpwent (void); /* Read an entry from the password-file stream, opening it if necessary. This function is a possible cancellation point and therefore not marked with __THROW. */ extern struct passwd *getpwent (void); #endif #ifdef __USE_SVID /* Read an entry from STREAM. This function is not part of POSIX and therefore no official cancellation point. But due to similarity with an POSIX interface or due to the implementation it is a cancellation point and therefore not marked with __THROW. */ extern struct passwd *fgetpwent (FILE *__stream); /* Write the given entry onto the given stream. This function is not part of POSIX and therefore no official cancellation point. But due to similarity with an POSIX interface or due to the implementation it is a cancellation point and therefore not marked with __THROW. */ extern int putpwent (__const struct passwd *__restrict __p, FILE *__restrict __f); #endif /* Search for an entry with a matching user ID. This function is a possible cancellation point and therefore not marked with __THROW. */ extern struct passwd *getpwuid (__uid_t __uid); /* Search for an entry with a matching username. This function is a possible cancellation point and therefore not marked with __THROW. */ extern struct passwd *getpwnam (__const char *__name); #if defined __USE_POSIX || defined __USE_MISC # ifdef __USE_MISC /* Reasonable value for the buffer sized used in the reentrant functions below. But better use ‘sysconf’. */ # define NSS_BUFLEN_PASSWD 1024 # endif /* Reentrant versions of some of the functions above. PLEASE NOTE: the ‘getpwent_r’ function is not (yet) standardized. The interface may change in later versions of this library. But the interface is designed following the principals used for the other reentrant functions so the chances are good this is what the POSIX people would choose. */ # if defined __USE_SVID || defined __USE_MISC /* This function is not part of POSIX and therefore no official cancellation point. But due to similarity with an POSIX interface or due to the implementation it is a cancellation point and therefore not marked with __THROW. */ extern int getpwent_r (struct passwd *__restrict __resultbuf, char *__restrict __buffer, size_t __buflen, struct passwd **__restrict __result); # endif extern int getpwuid_r (__uid_t __uid, struct passwd *__restrict __resultbuf, char *__restrict __buffer, size_t __buflen, struct passwd **__restrict __result); extern int getpwnam_r (__const char *__restrict __name, struct passwd *__restrict __resultbuf, char *__restrict __buffer, size_t __buflen, struct passwd **__restrict __result); # ifdef __USE_SVID /* Read an entry from STREAM. This function is not standardized and probably never will. This function is not part of POSIX and therefore no official cancellation point. But due to similarity with an POSIX interface or due to the implementation it is a cancellation point and therefore not marked with __THROW. */ extern int fgetpwent_r (FILE *__restrict __stream, struct passwd *__restrict __resultbuf, char *__restrict __buffer, size_t __buflen, struct passwd **__restrict __result); # endif #endif /* POSIX or reentrant */ #ifdef __USE_GNU /* Re-construct the password-file line for the given uid in the given buffer. This knows the format that the caller will expect, but this need not be the format of the password file. This function is not part of POSIX and therefore no official cancellation point. But due to similarity with an POSIX interface or due to the implementation it is a cancellation point and therefore not marked with __THROW. */ extern int getpw (__uid_t __uid, char *__buffer); #endif __END_DECLS #endif /* pwd.h */ The fields _p_w__q_u_o_t_a and _p_w__c_o_m_m_e_n_t are unused; the others have meanings described in _p_a_s_s_w_d(5). Searching of the password file is done using the _n_d_b_m database access routines. _S_e_t_p_w_e_n_t opens the database; _e_n_d_p_w_e_n_t closes it. _G_e_t_p_w_u_i_d and _g_e_t_p_w_n_a_m search the database (opening it if necessary) for a match‐ ing _u_i_d or _n_a_m_e. EOF is returned if there is no entry. For programs wishing to read the entire database, _g_e_t_p_w_e_n_t reads the next line (opening the database if necessary). In addition to opening the database, _s_e_t_p_w_e_n_t can be used to make _g_e_t_p_w_e_n_t begin its search from the beginning of the database. _S_e_t_p_w_f_i_l_e changes the default password file to _n_a_m_e thus allowing alternate password files to be used. Note that it does _n_o_t close the previous file. If this is desired, _e_n_d_p_w_e_n_t should be called prior to it. FILES /etc/passwd SEE ALSO getlogin(3), getgrent(3), passwd(5) DIAGNOSTICS The routines _g_e_t_p_w_e_n_t, _g_e_t_p_w_u_i_d, and _g_e_t_p_w_n_a_m, return a null pointer (0) on EOF or error. BUGS All information is contained in a static area so it must be copied if it is to be saved. 7th Edition May 15, 1986 GETPWENT(3)