1 files changed, 51 insertions, 0 deletions
diff --git a/doc/crypto/ERR_GET_LIB.pod b/doc/crypto/ERR_GET_LIB.pod
new file mode 100644
index 000000000000..2a129da036cc
--- /dev/null
+++ b/doc/crypto/ERR_GET_LIB.pod
@@ -0,0 +1,51 @@
+=pod
+
+=head1 NAME
+
+ERR_GET_LIB, ERR_GET_FUNC, ERR_GET_REASON - get library, function and
+reason code
+
+=head1 SYNOPSIS
+
+ #include <openssl/err.h>
+
+ int ERR_GET_LIB(unsigned long e);
+
+ int ERR_GET_FUNC(unsigned long e);
+
+ int ERR_GET_REASON(unsigned long e);
+
+=head1 DESCRIPTION
+
+The error code returned by ERR_get_error() consists of a library
+number, function code and reason code. ERR_GET_LIB(), ERR_GET_FUNC()
+and ERR_GET_REASON() can be used to extract these.
+
+The library number and function code describe where the error
+occurred, the reason code is the information about what went wrong.
+
+Each sub-library of OpenSSL has a unique library number; function and
+reason codes are unique within each sub-library.  Note that different
+libraries may use the same value to signal different functions and
+reasons.
+
+B<ERR_R_...> reason codes such as B<ERR_R_MALLOC_FAILURE> are globally
+unique. However, when checking for sub-library specific reason codes,
+be sure to also compare the library number.
+
+ERR_GET_LIB(), ERR_GET_FUNC() and ERR_GET_REASON() are macros.
+
+=head1 RETURN VALUES
+
+The library number, function code and reason code respectively.
+
+=head1 SEE ALSO
+
+L<err(3)|err(3)>, L<ERR_get_error(3)|ERR_get_error(3)>
+
+=head1 HISTORY
+
+ERR_GET_LIB(), ERR_GET_FUNC() and ERR_GET_REASON() are available in
+all versions of SSLeay and OpenSSL.
+
+=cut