%META:TOPICPARENT{name="ErrorMessagesU"}%

=Unresolved symbol <symbol> or Undefined reference to <symbol>=
%TOC%
==General Guidance==

To resolve these errors, start by finding where the missing symbols are defined:

# Access the machine, which contains your <nop>OpenLink server components installation.
# <code>cd</code> into your database's <code><nowiki>/lib</nowiki></code> sub-directory.
# Run the following command: 
%BR%<blockquote><code><nowiki> nm -A *.so &#124; grep &lt;symbol&gt; </nowiki></code></blockquote>%BR%
For example, if the error you got was "<code><nowiki>Unresolved symbol xsendto</nowiki></code>" or "<code><nowiki>Undefined reference to xsendto</nowiki></code>", the command would be
%BR%<blockquote><code><nowiki> nm -A *.so &#124; grep xsendto </nowiki></code></blockquote>%BR%
# If the symbol does not exist, stop and contact <nop>OpenLink Product Support. Otherwise,....
# Record the names of the files which contain your symbols. The filename will be the first item in the <code>nm</code> output.

==If the error messages came up during a Multi-Tier Generic Client installation==

Add the directory/ies that contains the library/ies found above to the shared library environment variable for your OS (i.e., <code><nowiki>LD_LIBRARY_PATH</nowiki></code>, <code><nowiki>LIBPATH</nowiki></code>, or <code><nowiki>SHLIB_PATH</nowiki></code>). For example:
%BR%<blockquote><code><nowiki>set LIBPATH&#061;/app/product/oracle/8.0.4/lib:$LIBPATH</nowiki></code></blockquote>%BR%


==If the error messages came up while relinking a Multi-Tier Database Agent or Single-Tier Lite Driver for Progress, on Linux ==

//For errors regarding <code>__ctype_b</code>, <code>__ctype_tolower</code>, and <code>__ctype_toupper</code>, follow the guidance in this section.  For other errors, proceed to the next section below.//

//Instructions in this section were based on Progress Knowledgebase Article ID#P101259.//

32-bit <nop>OpenEdge 10.1B and earlier, including Progress 9.1x and earlier, are built on <nop>RedHat 2.1, with an older version of glibc (2.3.2-5 or earlier).  These older versions of glibc contain definitions of <code>__ctype_b</code>, <code>__ctype_tolower</code>, and <code>__ctype_toupper</code>.

These definitions are not contained in more recent versions of glibc -- but they remain necessary for Database Agent or Lite Driver relinking.  You can either relink on a Linux machine which has such an older version of glibc (again, 2.3.2-5 or earlier), or follow the instructions below.

# Create a file named "<code>libctype.c</code>" with these contents --
{{{
#include <stdlib.h>
#include <ctype.h>

__const unsigned short int * __ctype_b;
__const __int32_t  * __ctype_tolower;
__const __int32_t  * __ctype_toupper;

void __attribute__((constructor)) my_init() {
   __ctype_b = * __ctype_b_loc();
   __ctype_tolower = * __ctype_tolower_loc();
   __ctype_toupper = * __ctype_toupper_loc();
}

void __attribute__((destructor)) my_clean() {
}
}}}
# Compile that with the command --
{{{
gcc -O2 -shared -o libctype.so libctype.c
}}}
# Amend your {{{ldpro}}} script, or {{{build_rx.sh}}} for <nop>OpenEdge 10, to include a reference to the newly created {{{libctype.so}}} library.
# Execute the {{{ldpro}}} script, or {{{build_rx.sh}}} for <nop>OpenEdge 10; the build should now succeed.
# Be sure to deploy the new {{{libctype.so}}} along with the executable you just built, as the executable now depends on this library.


==If the error messages came up while relinking any other Multi-Tier Database Agent or Single-Tier Lite Driver==

# <code>cd</code> into the <code><nowiki>/lib</nowiki></code> sub-directory of your <nop>OpenLink installation.
# Open the script which produced the error in your favorite text editor (vi, emacs, etc.).
# Determine where to add the new library. Most often, it is added to the <code>cc -s -o</code> line. Oracle users must add it to the <code>make -f</code> line. Progress users who encounter errors with <code>mkdlc</code> must add it to <code>$PRO_EXTRA</code>. For example:
%BR%<blockquote><code><nowiki>$PRO_EXTRA \ $PROLOAD/4gl/&lt;missing file&gt;.o \ </nowiki></code></blockquote>%BR%
# Save your changes and exit your relink script.
# Relink your database agent.


==Evidence==

* Database Agent Version String
* DBMS Version
* Relink Script(s)
* Output of <code>uname -a</code>