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Sono un novizio di Linux (proveniente da uno sfondo di Windows). Mi piacerebbe capire i dettagli di come gli oggetti condivisi (file .so) vengono caricati in fase di runtime. Secondo http://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html il file /etc/ld.so.conf configura le directory per cercare i file .so in fase di runtime. Tuttavia un esperimento mostrato di seguito sembra indicare che non è il caso./usr/local/lib è in uno dei file .conf in /etc/ld.so.conf.d, ma quando il mio .so è in/usr/local/lib non viene trovato in fase di esecuzione. Al contrario/usr/lib è non configurato da /etc/ld.so.conf, ma quando il mio .so è in/usr/lib è trovato in runtime..so percorsi di ricerca
Cosa mi manca?
Grazie, Dave
[email protected]:/$ # Display the .so search path configured in /etc/ld.so.conf
[email protected]:/$ cat /etc/ld.so.conf
include /etc/ld.so.conf.d/*.conf
[email protected]:/$ cat /etc/ld.so.conf.d/*.conf
/usr/lib/mesa
/usr/lib32/mesa
/usr/lib32/alsa-lib
/usr/lib/alsa-lib
# libc default configuration
/usr/local/lib
# Multiarch support
/lib/x86_64-linux-gnu
/usr/lib/x86_64-linux-gnu
[email protected]:/$ # libsotest.so.1 is in /usr/local/lib
[email protected]:/$ ls -la /usr/local/lib/libsotest*
lrwxrwxrwx 1 root root 14 2012-07-19 08:24 /usr/local/lib/libsotest.so -> libsotest.so.1
lrwxrwxrwx 1 root root 18 2012-07-19 08:24 /usr/local/lib/libsotest.so.1 -> libsotest.so.1.0.1
-rwxr-xr-x 1 davids davids 7952 2012-07-19 08:13 /usr/local/lib/libsotest.so.1.0.1
[email protected]:/$ # But when I run an executable that refrs to libsotest.so.1, the loader doesn't find it.
davids[email protected]:/$ /projects/sotest/exe/sotestexe
/projects/sotest/exe/sotestexe: error while loading shared libraries: libsotest.so.1: cannot open shared object file: No such file or directory
[email protected]:/$ # Configure loader to display the paths it's searching...it's searching /usr/lib but not /usr/local/lib
[email protected]:/$ export LD_DEBUG=lib
[email protected]:/$ /projects/sotest/exe/sotestexe
warning: debug option `lib' unknown; try LD_DEBUG=help
/projects/sotest/exe/sotestexe: error while loading shared libraries: libsotest.so.1: cannot open shared object file: No such file or directory
[email protected]:/$ export LD_DEBUG=libs
[email protected]:/$ /projects/sotest/exe/sotestexe
6691: find library=libsotest.so.1 [0]; searching
6691: search cache=/etc/ld.so.cache
6691: search path=/lib/tls/x86_64:/lib/tls:/lib/x86_64:/lib:/usr/lib/tls/x86_64:/usr/lib/tls:/usr/lib/x86_64:/usr/ lib:/lib/x86_64-linux-gnu/tls/x86_64:/lib/x86_64-linux-gnu/tls:/lib/x86_64-linux- gnu/x86_64:/lib/x86_64-linux-gnu:/usr/lib/x86_64-linux-gnu/tls/x86_64:/usr/lib/x86_64-linux- gnu/tls:/usr/lib/x86_64-linux-gnu/x86_64:/usr/lib/x86_64-linux-gnu (system search path)
6691: trying file=/lib/tls/x86_64/libsotest.so.1
6691: trying file=/lib/tls/libsotest.so.1
6691: trying file=/lib/x86_64/libsotest.so.1
6691: trying file=/lib/libsotest.so.1
6691: trying file=/usr/lib/tls/x86_64/libsotest.so.1
6691: trying file=/usr/lib/tls/libsotest.so.1
6691: trying file=/usr/lib/x86_64/libsotest.so.1
6691: trying file=/usr/lib/libsotest.so.1
6691: trying file=/lib/x86_64-linux-gnu/tls/x86_64/libsotest.so.1
6691: trying file=/lib/x86_64-linux-gnu/tls/libsotest.so.1
6691: trying file=/lib/x86_64-linux-gnu/x86_64/libsotest.so.1
6691: trying file=/lib/x86_64-linux-gnu/libsotest.so.1
6691: trying file=/usr/lib/x86_64-linux-gnu/tls/x86_64/libsotest.so.1
6691: trying file=/usr/lib/x86_64-linux-gnu/tls/libsotest.so.1
6691: trying file=/usr/lib/x86_64-linux-gnu/x86_64/libsotest.so.1
6691: trying file=/usr/lib/x86_64-linux-gnu/libsotest.so.1
6691:
/projects/sotest/exe/sotestexe: error while loading shared libraries: libsotest.so.1: cannot open shared object file: No such file or directory
[email protected]:/$