NAME    [Toc]    [Back]

     pw_dup - make a copy of a struct passwd

SYNOPSIS    [Toc]    [Back]

     #include <pwd.h>

     struct passwd *
     pw_dup(const struct passwd *pw);

DESCRIPTION    [Toc]    [Back]

     The pw_dup() function allocates sufficient memory for a copy
of the
     struct  passwd  pw,  does the copy, and returns a pointer to
it.  This is
     useful as subsequent calls to  getpwent(),  getpwnam(),  and
getpwuid() will
     overwrite the data from previous calls.

     The  returned pointer may be deallocated by a single call to
free(3).
     Since pw_dup() allocates space for the copy in one chunk  it
is not necessary
  to  free  the  individual strings contained in the returned struct
     passwd.

     If insufficient memory is available, NULL is returned.

EXAMPLES    [Toc]    [Back]

     The following will make a copy of the struct passwd for root
and store it
     in "pw_save":

           struct passwd *pw, *pw_save;

           if ((pw = getpwnam("root")) == NULL) {
                   fprintf(stderr, "Cannot find root in the password file.0);
                   exit(1);
           }
           if ((pw_save = pw_dup(pw)) == NULL) {
                   fprintf(stderr, "Out of memory.0);
                   exit(1);
           }

ERRORS    [Toc]    [Back]

     pw_dup() function may fail and  set  the  external  variable
errno for any of
     the errors specified for the library function malloc(3).

SEE ALSO    [Toc]    [Back]

     free(3), getpwent(3), malloc(3)

HISTORY    [Toc]    [Back]

     The pw_dup() function first appeared in OpenBSD 2.9.

OpenBSD      3.6                        November     15,     2000