linux - [Solved-3 Solutions] How to merge two “ar” static libraries into one ? - ubuntu - red hat - debian - linux server - linux pc

How to merge two “ar” static libraries into one ?

You can extract the object from both the .a files and create your .a file using the extracted .os:

ar -x libabc.a
ar -x libxyz.a
ar -c libaz.a  *.o

libtool --mode=link cc -static -o libaz.la libabc.la libxyz.la

The other two are at least available when using GNU ar. You can use an MRI script (named for example libaz.mri), such as:

create libaz.a
addlib libabc.a
addlib libxyz.a
save
end

and then execute ar as:

ar -M <libaz.mri

You can use a thin archive (option -T), which will allow adding other archives without getting them nested inside, although the downside is that if you want to distribute the static library, the detached object will be missing:

ar -rcT libaz.a libabc.a libxyz.a

All the above methods gracefully handle overlapping member names from the original archives.

Otherwise, you'd have to unpack into different directories and repack again, to avoid replacing overlapping member names:

mkdir abc; cd abc; ar -x ../libabc.a
mkdir xyz; cd xyz; ar -x ../libxyz.a
ar -qc libaz.a abc xyz

You can try this:

ar x a.a
ar x b.a
ar c c.a  *.o 

You will lost some object files if there are members with same name in both a.a and b.a so, you need to extract members of different archives into different folder:

ar x a.a && mv *.o a_objs
ar x b.a && mv *.o b_objs
ar c c.a a_objs/*.o b_objs/*.o

Additionally, it is posible that there are multiple members of same name in one archive (say in a.a), if you run ar x a.a, you will get only one for those members of same name.

The only way to extract all members of same name in one archive is to specify the member number by option 'N':

ar xN 1 a.a  xxx.c.o && mv xxx.c.o xxx.c.1.o
ar xN 2 b.a  xxx.c.o && mv xxx.c.o xxx.c.2.o
...

One optional solutions is that you can combine multiple archives into one shared library:

g++ -shared -o c.so -Wl,--whole-archive a.a b.a