This section explains how a program can read the list of all users in the system, one user at a time. The functions described here are declared in `pwd.h'.
You can use the fgetpwent
function to read user entries from a
particular file.
fgetpwent
. You must copy the
contents of the structure if you wish to save the information.
The stream must correspond to a file in the same format as the standard password database file.
fgetpwent
in that it reads the next
user entry from stream. But the result is returned in the
structure pointed to by result_buf. The
first buflen bytes of the additional buffer pointed to by
buffer are used to contain additional information, normally
strings which are pointed to by the elements of the result structure.
The stream must correspond to a file in the same format as the standard password database file.
If the function returns zero result points to the structure with the wanted data (normally this is in result_buf). If errors occurred the return value is nonzero and result contains a null pointer.
The way to scan all the entries in the user database is with
setpwent
, getpwent
, and endpwent
.
getpwent
and
getpwent_r
use to read the user database.
getpwent
function reads the next entry from the stream
initialized by setpwent
. It returns a pointer to the entry. The
structure is statically allocated and is rewritten on subsequent calls
to getpwent
. You must copy the contents of the structure if you
wish to save the information.
A null pointer is returned when no more entries are available.
getpwent
in that it returns the next
entry from the stream initialized by setpwent
. Like
fgetpwent_r
, it uses the user-supplied buffers in
result_buf and buffer to return the information requested.
The return values are the same as for fgetpwent_r
.
getpwent
or
getpwent_r
.
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