getpwent(3)getpwent(3)NAME
endpwent, fgetpwent, getpwent, getpwnam, getpwuid, putpwent, setpwent,
setpwfile, endpwent_r, fgetpwent_r, getpwent_r, getpwnam_r, getpwuid_r,
setpwent_r - Access user attribute information in the user database
SYNOPSIS
#include <pwd.h>
void endpwent(
void ); struct passwd *fgetpwent(
FILE *f ); struct passwd *getpwent(
void ); struct passwd *getpwnam(
const char *name ); struct passwd *getpwuid(
uid_t uid ); int putpwent(
struct passwd *passwd,
FILE *file ); void setpwent(
void ); void setpwfile(
const char *filename ); void endpwent_r(
FILE **pw_fp ); int fgetpwent_r(
FILE *f,
struct passwd *pwd,
char *buffer,
int len ); int getpwent_r(
struct passwd *pwd,
char *buffer,
int len,
FILE **pw_fp ); int getpwnam_r(
const char *name,
struct passwd *pwd,
char *buffer,
size_t len,
struct passwd **result ); int getpwuid_r(
uid_t uid,
struct passwd *pwd,
char *buffer,
size_t len,
struct passwd **result ); int setpwent_r(
FILE **pw_fp );
The following functions do not conform to industry standards and are
supported only for backward compatibility reasons. You should not use
them in new designs. int setpwent(
void ); int getpwnam_r(
const char *name,
struct passwd *result,
char *buffer,
int len ); int getpwuid_r(
uid_t uid,
struct passwd *result,
char *buffer,
int len );
LIBRARY
Standard C Library (libc)
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
endpwent(), getpwent(), getpwnam(), getpwnam_r(), getpwuid(), getp‐
wuid_r(), setpwent(): XSH5.0
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
PARAMETERS
Specifies the ID of the user for which the attributes are to be read.
Specifies the name of the user for which the attributes are to be read.
Specifies the location where the retrieved passwd structure is to be
placed. Specifies the password structure that contains the user
attributes that are to be written. Specifies a stream open for writing
to a file. Upon successful return, points to the retrieved passwd
structure. Upon unsuccessful return, the result is set to NULL. A
working buffer for the result parameter that is able to hold the
largest password entry in /etc/passwd.
[Tru64 UNIX] The minimum buffer size is 1024 bytes as defined
for SIABUFSIZ in /usr/include/sia.h. Specifies the length of
the character array that buffer points to.
[Tru64 UNIX] The minimum buffer size is 1024 bytes as defined
for SIABUFSIZ in /usr/include/sia.h. Specifies a file that con‐
tains the next passwd structure. (This is for the fgetpwent()
and fgetpwent_r() functions.) Points to a file stream open for
reading password entries. Specifies a new default password file
rather than using the default /etc/passwd file.
DESCRIPTION
The endpwent(), fgetpwent(), getpwent(), getpwnam(), getpwuid(), putp‐
went(), and setpwent() functions may be used to access the basic user
attributes.
The getpwent(), getpwnam(), and getpwuid() functions return information
about the specified user. The getpwent() function returns the next
user entry in a sequential search that may use a private file pointer.
The getpwnam() function returns the first user entry in the database
with a pw_name field that matches the name parameter. The getpwuid()
function returns the first user entry in the database with a pw_uid
field that matches the uid parameter.
The putpwent() function writes a password entry into a file in the
colon-separated format of the /etc/passwd file.
The setpwent() function ensures that the next call to getpwent()
returns the first entry.
The endpwent() function closes the user database and any private stream
used by getpwent(). When the /etc/passwd file is updated, it may be
necessary to call endpwent() to ensure that subsequent getpwent() calls
will return the new data.
The user structure, which is returned by the getpwent(), getpwnam(),
and getpwuid() functions and which is written by the putpwent() func‐
tion, is defined in the pwd.h file and has the following members: The
name of the user. The encrypted password of the user. If the password
is not stored in the /etc/passwd file and the invoker does not have
access to the shadow file that contains them, this field will contain
an unencryptable string. The ID of the user. The group ID of the
principle group of the user. The personal information about the user.
The home directory of the user. The initial program for the user.
The endpwent_r(), fgetpwent_r()getpwent_r(), getpwnam_r(), getp‐
wuid_r(), and setpwent_r() functions are the reentrant versions of the
endpwent(), fgetpwent()getpwent(), getpwnam(), getpwuid(), and setp‐
went() functions, respectively.
The endpwent_r(), getpwent_r(), and setpwent_r() functions use the
pw_fp parameter to keep track of the calls to the getpwent_r() func‐
tion, so that subsequent calls will return subsequent password entries
from the /etc/passwd file. The setpwent_r() function must be called
with the address of a valid file pointer (which may be NULL). Upon suc‐
cessful completion, the result is stored in result.
The fgetpwent() and fgetpwent_r() functions get a password file entry
from the file specified by the f parameter, rather than from the
/etc/passwd file. This file must have the format of the /etc/passwd
file.
The setpwfile() function sets the new default password file to be file‐
name instead of /etc/passwd.
[Tru64 UNIX] The system searches using NIS if NIS is available and
your /etc/passwd file has NIS type entries (that is, +:, +name, +@net‐
group, and -@netgroup). The fgetpw* routines do not use NIS. The oper‐
ating system provides the getpwent_local, getpwuid_local, and getpw‐
nam_local routines to avoid NIS. The getpw*_local routines are propri‐
etary and are not in the pwd.h header file.
NOTES
All information generated by the fgetpwent(), getpwent(), getpwnam(),
and getpwuid() functions is stored in a static area and will be over‐
written on subsequent calls to these routines. These static areas may
include private I/O streams or network resources.
Password file entries that are too long are ignored.
Note that the pw_fp parameter must be initialized by the user to NULL
before the setpwent_r() function is called for the first time.
RETURN VALUES
Upon successful completion, the fgetpwent(), getpwent(), getpwnam(),
and getpwuid() functions return a pointer to a valid password struc‐
ture. Otherwise, NULL is returned.
Upon successful completion, the getpwnam_r and getpwuid_r functions
return a value of 0 (zero). If the user or group is not found in the
password or group database, these routines return 0 for the status and
a NULL in the returned "result" pointer.
Upon successful completion, the fgetpwent_r() and getpwent_r() func‐
tions (as well as the obsolete versions of the getpwnam_r() and getp‐
wuid_r() functions, return a value of 0 (zero). Otherwise, they return
a value of -1 and set errno to indicate the error.
ERRORS
If any of the following conditions occurs, the getpwnam_r(), and getp‐
wuid_r() functions set errno to the corresponding value: The amount of
storage specified by buffer and len is too small to contain the data to
be referenced by the resulting struct passwd structure.
FILESSEE ALSO
Functions: getgrent(3), sia_getpasswd(3)
Standards: standards(5)getpwent(3)
