.\" added _XOPEN_SOURCE, aeb, 970705
.\" added GNU MD5 stuff, aeb, 011223
.\"
-.TH CRYPT 3 2010-06-20 "" "Linux Programmer's Manual"
+.TH CRYPT 3 2011-09-15 "" "Linux Programmer's Manual"
.SH NAME
crypt, crypt_r \- password and data encryption
.SH SYNOPSIS
.sp
.BI "char *crypt(const char *" key ", const char *" salt );
.sp
+.BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */"
+.br
+.B #include <crypt.h>
+.sp
.BI "char *crypt_r(const char *" key ", const char *" salt ,
.BI " struct crypt_data *" data );
.fi