AstRecipes » Checking library dependencies
This not is not - strictly speaking - an Asterisk issue; but I present it here as it sometimes pops up with Asterisk installations, after compiling shared libraries (for example, OH323). A typpical example is in fact an error like the one here below: [chan_oh323.so]May 2 15:41:29 WARNING[-1218537120]: loader.c:242 ast_load_resource: liboh323wrap.so: cannot open shared object file: No such file or directory
May 2 15:41:29 WARNING[-1218537120]: loader.c:423 load_modules: Loading module chan_oh323.so failed!
A shared library is a piece of compiled code that can be shared by more than one program on your system. This way, utility libraries need not be embedded in each and every executable that is on your disk. The cons are that if you copy a program and it does not find the exact libraries it needs in the designated system folders, it will simply refuse to run. How do I find which shared libraries are required by a module?
The command ldd is your friend. It will report something like:
[root@vm lib]# ldd /usr/lib/asterisk/modules/chan_oh323.so
liboh323wrap.so => /lib/liboh323wrap.so (0x00bf2000)
libh323_linux_x86_r.so.1.13.5 => not found
libpt_linux_x86_r.so.1.6.6 => not found
libstdc++.so.5 => /usr/lib/libstdc++.so.5 (0x008fc000)
libpthread.so.0 => /lib/tls/libpthread.so.0 (0x009ff000)
libdl.so.2 => /lib/libdl.so.2 (0x00add000)
libc.so.6 => /lib/tls/libc.so.6 (0x00111000)
libm.so.6 => /lib/tls/libm.so.6 (0x0025c000)
libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x0034b000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x00b98000)
If you compiled the packes yourself, chances are that the shared libraries you are looking for are present on your system, but in the wrong locations. To understand if that is the case, simply run the locate command, like here below:
[root@vm lib]# locate libh323_linux_x86_r.so.1.13.5
/root/asterisk/openh323/lib/libh323_linux_x86_r.so.1.13.5
