[fpc-pascal] how to install sqlite server side library on CentOS
lacak at zoznam.sk
Sun Dec 8 11:24:20 CET 2013
Dennis Poon wrote / napísal(a):
> Jonas Maebe wrote:
>> On 06 Dec 2013, at 18:45, Dennis Poon wrote:
>>> My server program written in fpc uses sqlite3 and
>>> in ubuntu, I just need to
>>> apt-get install libsqlite3-dev
>>> but in centos, the libsqlite3-dev does not exist and the client lib
>>> yum install sqlite
>>> was not enough.
>>> The server program still complained: libsqlite3.so
>>> is missing.
>> The default behaviour of almost all FPC database units is buggy in
>> the sense that they look for *.so instead of for *.so.0, *.so.1 or
>> similar files. The *.so file indeed only exists if you install the
>> development addendum of a package, and it's just a symlink to the
>> latest supported version (which is a *.so.0, *.so.1 or similar file).
>> The only purpose of such a symlink is that in case you link to a
>> library at compile time, the program will be linked against this
>> latest installed version (under the assumption that it was also
>> compiled using the .h files installed on the system, which belong to
>> this same latest installed version). They should definitely never be
>> used for dynamic loading, because
>> a) they generally do not (and should not) exist on user systems
>> b) they could point to any version, and the unit loading it may not
>> support that version
>> In case of FPC, they actually shouldn't be used in case of
>> compile-time linking either because of point b) above, and we should
>> again explicitly link to specific versions.
>> Anyway, you can work around the specific problem you are having by
>> telling the sqlite unit to use the specifically supported version by
>> calling InitialiseSQLite('libsqlite.so.0'). It will work on both
>> Ubuntu and CentOS and any other Linux distribution, and no one will
>> have to install any -dev packages.
> Thanks so much for your help but I tried putting
> which did not work.
> then I realised, you probably meant
> However, it then complained that "SQLIte interface already initialized
> from library libsqlite3.so.0."
> I seached files: sqlite3conn.pp, sqlite3dyn.pp, sqlite3.inc,
> dynlibs.inc but could not find where InitializeSQLite was called so
> could not replace that call from '.so' to '.so.0 '
> However, I did find the default library name, used by the function
> InitiliseSQLite if no parameter is passed to it, which is composed of
> a default file extension defined in file dynlibs.inc
> const SharedSuffix = 'so';
> Since it is a constant, I dared not change it.
> Eventually, I used command
> find / -name 'libsqlite3.so*'
> and found on this CentOS 64 bit machine:
> so, I created a symbolic link in /usr/lib64/
> ln -s libsqlite3.so.0 libsqlite3.so
> and finally, it worked!
> I don't know enough about database in FPC to suggest an improvement
> scheme but I do think such one is really in needed for future users.
Did you have tried :
SQLiteLibraryName := 'libsqlite3.so.0'; // SQLiteLibraryName is
defined in sqlite3conn.pp
sqlite3dyn.SQLiteDefaultLibrary := 'libsqlite3.so.0';
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