MirBSD manpage: pw_dup(3)

PW_DUP(3)                  BSD Programmer's Manual                   PW_DUP(3)

NAME

     pw_dup - make a copy of a struct passwd

SYNOPSIS

     #include <pwd.h>

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

DESCRIPTION

     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 they returned 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

     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.\n");
                   exit(1);
           }
           if ((pw_save = pw_dup(pw)) == NULL) {
                   fprintf(stderr, "Out of memory.\n");
                   exit(1);
           }

ERRORS

     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

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

HISTORY

     The pw_dup() function first appeared in OpenBSD 2.9.

MirBSD #10-current            November 15, 2000                              1