Hi,
I'm new to both Linux and Midas and having trouble installing the programme - 
the install file suggeats that I should have a directory:

midas/unix

but this doesn't appear.

Also, when running the "make" for the library (step 3 of the installation), I 
don't see the directory "zlib.a", but there is a "libz.a" and I note the 
original .tar file has no libz.a file in it. Is this a typo on the 
installation?
The terminal window at this point displays:

undefined reference to `errno'
make: ***[example] Error 1

Further help will no doubt be required as I've used windows throughout my 
research and now looking to learn how to use linux. Any help greatly 
appreciated. Thanks!

#define EXPCVADC_COMMON_STR(_name) char *_name[] = {\
"[.]",\
...

#define EXPCVADC_COMMON_STR(_name) const char *_name[] = {\
"[.]",\
...

char *s = "whatever";
...
strcpy(s, "Hello, this is a string longer than the initial one.");

status = db_create_record(hDB, 0, set_str, strcomb(expcvadc_settings_str));

cvadcfe.c: In function ‘frontend_init’:
cvadcfe.c:144: warning: passing argument 1 of ‘strcomb’ from incompatible pointer type

> Documentation for writing midas history data to SQL (mysql) is now documented in midas doxygen files 
> (make dox; firefox doxfiles/html/index.html). The corresponding logger and mhttpd code has been 
> committed for some time now and it is used in production environment by the t2k/nd280 slow controls 
> daq system at TRIUMF.
> svn rev 4487


An updated version of the SQL history code is now committed to midas svn.

The new code is in history_sql.cxx. It implements a C++ interface to the MIDAS history (history.h),
and improves on the old code history_odbc.cxx by adding:
- an index table for remembering MIDAS names of SQL tables and columns (our midas users like to use funny characters in history 
names that are not permitted in SQL table and column names),
- caching of database schema (event names, etc) with a noticeable speedup of mhttpd (there is a new button on the history panel editor 
"clear history cache" to make mhttpd reload the database schema.

The updated documentation for using SQL history is committed to midas svn doxfiles/internal.dox (svn up; make dox; firefox 
doxfiles/html/index.html), or see my copy on the web at
http://ladd00.triumf.ca/~olchansk/midas/Internal.html#History_sql_internal

svn rev 4595
K.O.

> > Why is the class "SqlODBC" duplicated?
> 
> This is interesting. I do not think my C++ book spells it out that I cannot have class A in foo.cxx
> and a class A in bar.cxx.

I guess nobody knows the answer to this C++ puzzle. In any case history_odbc.cxx is not used anymore removing duplication of class SqlODBC.

svn rev 4594
K.O.

> > > 	$(CXX) -shared -o $@ $^ $(LIBS) -lc

Done.
MIDAS shared library renamed from libmidas.so to libmidas-shared.so and always build on Linux (.so) and MacOS (.dylib and .so bundle).

Users who wish to link their applications to the shared library should change their Makefile from "gcc ... -lmidas" to "gcc ... -lmidas-shared".

MIDAS core applications (mhttpd, mlogger, etc) are linked to the static library to permit multiple versions of midas to be used
at the same time (LD_LIBRARY_PATH should point to the shared library for *which* midas?!?), avoid problems with wrong setting
of LD_LIBRARY_PATH and to avoid problems with version skew (which we found unavoidable once a midas daq is used for a year or
more - main reason we gave up on using the midas shared library in the first place).

svn rev 4594
K.O.

>  The "g++" is whining while compiling history_midas.cxx. Please see the attached log file.

Fixed. svn 4594. K.O.

Platform: Debian Linux testing
Compiler: gcc 4.3.4 (Debian 4.3.4-2)
Arch: x86
Description:
  The "g++" is whining while compiling history_midas.cxx. Please see the attached log file.
This can be fixed by add "#include <cstdlib>" to the C++ source. You know, different versions
of g++ don't act the same way. I think, maybe in version 4.2 or before, g++ can automatically
include the C header "stdlib.h" (which in C++ should be <cstdlib> because of some confusion
between C and C++), but not in version 4.3 or later. I tested g++-4.4, the problem still exists.
And g++-4.2 gives no error.

> Linking CXX shared library lib/libmidas.so
/usr/bin/c++  ... -o lib/libmidas.so ... CMakeFiles/midas-shared.dir/src/history_odbc.cxx.o 
CMakeFiles/midas-shared.dir/src/history_sql.cxx.o 
CMakeFiles/midas-shared.dir/src/history_sql.cxx.o: In function `SqlODBC':
/opt/DAQ/repos/bot/midas/src/history_sql.cxx:200: multiple definition of `SqlODBC::SqlODBC()'
CMakeFiles/midas-
shared.dir/src/history_odbc.cxx.o:/opt/DAQ/repos/bot/midas/src/history_odbc.cxx:315: first defined 
here
> Why is the class "SqlODBC" duplicated?

This is interesting. I do not think my C++ book spells it out that I cannot have class A in foo.cxx
and a class A in bar.cxx. In fact I already discovered that the two classes A will collide (duplicate default 
constructor A::A, even if all other member functions are different) if I link an executable that uses both 
foo.o and bar.o.

Is there a way around this problem? In C, I can declare functions and variables "static" to "hide" them
from the linker.

What is the C++ equivalent for classes? (Any C++ experts here?)

In this specific case, the file history_odbc.cxx will disappear with the next commit of mhttpd, hopefully 
today. mlogger and mh2sql already do not use it.

And I will commit the Makefile change renaming libmidas.so to libmidas-shared.so, so we can build it 
by default but still link midas core executables to the normal midas library.

This will catch such a problem if it happens again.

K.O.

> --- Makefile
> < 	ld -shared -o $@ $^ $(LIBS) -lc
> ---
> > 	$(CXX) -shared -o $@ $^ $(LIBS) -lc

Will do. We also have a long standing request to change shared library name from lidmidas.so to libmidas-shared.so.

Different name for the .so file will permit us to build the shared library by default, but still link all MIDAS executables
with the static libmidas.a.

(there is no benefit from linking MIDAS executables - mlogger, mhttpd, etc - with the shared library,
and there is a significant cost in confusion from version skew between the executables and shared
libraries - I have had enough midnight calls "why did odbedit stop working? Oh, who changed LD_LIBRARY_PATH
and why is it now binding against this obsolete libmidas.so left over from 2 years ago?").

For user applications you can do whatever, but for MIDAS core applications I strongly suggest that they
be linked to the midas static library.

K.O.

$ grep -n "class SqlODBC" src/*
src/history_odbc.cxx:282:class SqlODBC: public SqlBase
src/history_sql.cxx:293:class SqlODBC: public SqlBase

Linking CXX shared library lib/libmidas.so
/usr/bin/cmake -E cmake_link_script CMakeFiles/midas-shared.dir/link.txt --verbose=1
/usr/bin/c++  -fPIC   -shared -Wl,-soname,libmidas.so -o lib/libmidas.so CMakeFiles/midas-shared.dir/src/ftplib.c.o CMakeFiles/midas-shared.dir/src/midas.c.o CMakeFiles/midas-shared.dir/src/system.c.o CMakeFiles/midas-shared.dir/src/mrpc.c.o CMakeFiles/midas-shared.dir/src/odb.c.o CMakeFiles/midas-shared.dir/src/ybos.c.o CMakeFiles/midas-shared.dir/src/history.c.o CMakeFiles/midas-shared.dir/src/alarm.c.o CMakeFiles/midas-shared.dir/src/elog.c.o CMakeFiles/midas-shared.dir/opt/DAQ/repos/bot/mxml/mxml.c.o CMakeFiles/midas-shared.dir/opt/DAQ/repos/bot/mxml/strlcpy.c.o CMakeFiles/midas-shared.dir/src/history_odbc.cxx.o CMakeFiles/midas-shared.dir/src/history_sql.cxx.o 
CMakeFiles/midas-shared.dir/src/history_sql.cxx.o: In function `SqlODBC':
/opt/DAQ/repos/bot/midas/src/history_sql.cxx:200: multiple definition of `SqlODBC::SqlODBC()'
CMakeFiles/midas-shared.dir/src/history_odbc.cxx.o:/opt/DAQ/repos/bot/midas/src/history_odbc.cxx:315: first defined here
...
history_odbc.cxx:727: first defined here
collect2: ld returned 1 exit status
make[2]: *** [lib/libmidas.so] Error 1

I have experienced a problem building MIDAS from the head of the SVN repository (rev 4458) when 
specifying the shared library flag. Whie the shared library appears to compile and link OK, the 
subsequent compilation of mserver fails as follows:

$ make ROOTSYS= NEED_SHLIB=1

<... snipped some lines ...>

ld -shared -o linux/lib/libmidas.so linux/lib/midas.o linux/lib/system.o linux/lib/mrpc.o 
linux/lib/odb.o linux/lib/ybos.o linux/lib/ftplib.o linux/lib/mxml.o linux/lib/history_midas.o 
linux/lib/history_sql.o linux/lib/history.o linux/lib/alarm.o linux/lib/elog.o linux/lib/strlcpy.o -lutil -
lpthread -lz -lc
cc -c -g -O2 -Wall -Wuninitialized -Iinclude -Idrivers -I../mxml -Llinux/lib -DINCLUDE_FTPLIB   -
D_LARGEFILE64_SOURCE -DHAVE_ZLIB -DOS_LINUX -fPIC -Wno-unused-function -o linux/lib/mana.o 
src/mana.c
cc -c -g -O2 -Wall -Wuninitialized -Iinclude -Idrivers -I../mxml -Llinux/lib -DINCLUDE_FTPLIB   -
D_LARGEFILE64_SOURCE -DHAVE_ZLIB -DOS_LINUX -fPIC -Wno-unused-function -o 
linux/lib/cnaf_callback.o src/cnaf_callback.c
cc -c -g -O2 -Wall -Wuninitialized -Iinclude -Idrivers -I../mxml -Llinux/lib -DINCLUDE_FTPLIB   -
D_LARGEFILE64_SOURCE -DHAVE_ZLIB -DOS_LINUX -fPIC -Wno-unused-function -o linux/lib/mfe.o 
src/mfe.c
g++ -Dextname -DMANA_LITE -c -g -O2 -Wall -Wuninitialized -Iinclude -Idrivers -I../mxml -
Llinux/lib -DINCLUDE_FTPLIB   -D_LARGEFILE64_SOURCE -DHAVE_ZLIB -DOS_LINUX -fPIC -Wno-
unused-function -o linux/lib/fal.o src/fal.c
cc -g -O2 -Wall -Wuninitialized -Iinclude -Idrivers -I../mxml -Llinux/lib -DINCLUDE_FTPLIB   -
D_LARGEFILE64_SOURCE -DHAVE_ZLIB -DOS_LINUX -fPIC -Wno-unused-function -o 
linux/bin/mserver src/mserver.c -lmidas -Wl,-rpath,/usr/local/lib -lutil -lpthread -lz
/usr/bin/ld: linux/bin/mserver: hidden symbol `__dso_handle' in /usr/lib/gcc/x86_64-redhat-
linux/4.1.2/crtbegin.o is referenced by DSO
/usr/bin/ld: final link failed: Nonrepresentable section on output
collect2: ld returned 1 exit status
make: *** [linux/bin/mserver] Error 1

Having googled the error, it appears to be solved by modifying the linker statement for the shared 
library in the Makefile at line 464 to use g++ rather than ld:

463c463
< 	ld -shared -o $@ $^ $(LIBS) -lc
---
> 	$(CXX) -shared -o $@ $^ $(LIBS) -lc

Presumably this is because g++ knows better how to link in the appropriate system libraries required 
for some of the recently added C++ code? 

This was on Scientific Linux SL5.2 x86_64, gcc version 4.1.2, glibc version 2.5-24.

Tim

> The latest version of mfe.c has a problem where poll_event() is called before
> frontend_init() and this causes a crash because in poll_event() we try to access
> VME before it is initialized in frontend_init(). K.O.

Oops, that sneaked in when doing the last modification to display the frontend status. 
I refactored register_equipment() so that frontend_init() gets called before 
poll_event().

The latest version of mfe.c has a problem where poll_event() is called before
frontend_init() and this causes a crash because in poll_event() we try to access
VME before it is initialized in frontend_init(). K.O.

> Linking CXX executable bin/mh2sql
> CMakeFiles/mh2sql.dir/utils/mh2sql.cxx.o: In function `main':
> /opt/DAQ/repos/bot/midas/utils/mh2sql.cxx:150: undefined reference to `MakeMidasHistoryODBC()'

Yes, I am in the process of changing the midas history interface and accidentally committed a version of 
mh2sql (utility for converting MIDAS history .hst files to SQL database) that uses the new interface.

This is now fixed in svn rev 4571.

The new C++ interface to the MIDAS history is in include/history.h and implementations for data storage 
using both midas .hst files and SQL (ODBC/MySQL) database are also committed (history_midas.cxx
and history_sql.cxx). The file history_odbc.cxx will be removed after some more testing of the new 
interface.

(All the new code is not activated yet, pending more testing).

K.O.

> $ odbedit -e expcvadc
> odbedit: /opt/DAQ/repos/bot/midas/src/odb.c:651: db_validate_sizes: Assertion 
`sizeof(EQUIPMENT_INFO) == 400' failed.

Yes, this is now fixed, svn rev 4571 should be okey. Sorry about causing this problem - Stefan added 
some useful additional data to EQUIPMENT_INFO and my check for binary compatibility caught it and 
complained. Unfortunately on Saturday Stefan had to abruptly go back to PSI and things have been a little 
bit chaotic because we did not complete the testing of all the new changes and additions.

K.O.

-----------------------------------------------------------------------
r4568 | olchanski | 2009-09-27 23:56:39 +0800 (日, 27  9月 2009) | 5 lines

mhttpd: compile using the C++ compiler.
mhttpd: fix wrong initialization of /History/ODBC_DSN
odb.c: size of EQUIPMENT_INFO has changed.
Makefile: use "-O2" compiler flag instead of "-O3" - to fix SL5 gcc crash (ICE) 

Linking CXX executable bin/mh2sql
CMakeFiles/mh2sql.dir/utils/mh2sql.cxx.o: In function `main':
/opt/DAQ/repos/bot/midas/utils/mh2sql.cxx:150: undefined reference to `MakeMidasHistoryODBC()'

$ odbedit -e expcvadc
odbedit: /opt/DAQ/repos/bot/midas/src/odb.c:651: db_validate_sizes: Assertion `sizeof(EQUIPMENT_INFO) == 400' failed.
zsh: abort      odbedit -e expcvadc

> There is no "type conversions". The compiler is whining about code like this:
> 
> /* data type names */
> static char *tid_name[] = {
>    "NULL",
>    "BYTE",
>    ...
> 
> I guess we should keep the compiler happy and make them "static const char*".
> 
> BTW, my compiler is SL5.2 gcc-4.1.2 and it does not complain. What's your compiler?
> 
> K.O.

Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.3.4-2' --with-
bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs --enable-
languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared --enable-multiarch -
-enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-
gettext --enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.3 
--program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --
enable-mpfr --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --
host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.3.4 (Debian 4.3.4-2)

> I encountered many warning while building MIDAS (svn r4556). Please see the
> attached log file. Most of them are caused by type conversion from string to
> "char*".
> Though I can ignore all the warning without any problem, I still hate to see
> them. :-)

There is no "type conversions". The compiler is whining about code like this:

/* data type names */
static char *tid_name[] = {
   "NULL",
   "BYTE",
   ...

I guess we should keep the compiler happy and make them "static const char*".

BTW, my compiler is SL5.2 gcc-4.1.2 and it does not complain. What's your compiler?

K.O.