Verifying a programme is already installed or not in linux with config

[radmahdi]

I am trying to create a configure file for some library with the name for example "XYZ", so first of all I need to check this library is installed before or not?
for example for checking the library math we can use the following in the configure.ac file;
AC_CHECK_LIBM
AC_SUBST(LIBM)

but while trying autoconf with AC_CHECK_LIBXYZ or AC_CHECK_XYZ I get this error:
configure.ac:30: error: possibly undefined macro: AC_CHECK_LIBXYZ
If this token and others are legitimate, please use m4_pattern_allow.
See the Autoconf documentation.

I used AC_HAVE_LIBRARY([XYZ]) too, but while executing ./confgiure I got this:
checking for main in -lXYZ... no

I should add that the XYZ library is installed in /usr/local/XYZ

any idea will be appreciated,
Thanks

[Rubberman]

You can use the "whereis <libname>" command, such as "whereis libc".

[pradeepreddy3]

Hi,
You can first find config file by
find / -iname *config

This will list out files with suffix "config" . If you could not find the file XYZ.config in output then install package library package for "XYZ".

[radmahdi]

You can use the "whereis <libname>" command, such as "whereis libc".

great man, tnx...

Now, Do you know how can I compare it with prefix?

[pradeepreddy3]

can you post the error you are facing ..

[radmahdi]

can you post the error you are facing ..

Actually I am trying now to determine that my library is installed before or not?

with whereis <libname> I can find the path where my library is installed( /usr/local/XYZ)

Now, I wanna check if this path is equal to prefix or not? if it is not equal ask user "Are you sure..." (st like this)

I am not sure that this may be a good way.

Thanks m8 for your response.