Libtool

• Library
  • Program Library HOWTO
  • Dissecting shared libraries
  • Shared Library Search Paths
  • Developing LSB-certified applications

• Libtool
  • GNU Libtool 2.2.6

• Static Library
  • ar
  • ranlib

• Shared Library

Concept

• Shared libraries may only be built from position-independent code(PIC)
• the PIC one lives in the ‘.libs’ subdirectory and the static one lives in the current directory

Shared library support

• Shared library support for GNU v2.2.6, Shared library support for GNU v1.5.22

Version Scheme

• Versioning, Libtool versioning system
• Library Interface Versioning in Solaris and Linux

Search Paths

• Shared Library Search Paths
  • LD_LIBRARY_PATH
    • The dynamic linker searches the standard place by default, after the directories you have assigned to LD_LIBRARY_PATH
  • RPATH
    • Add -rpath or -R to the link command line
    • LD_RUN_PATH
      • The dynamic linker searches the standard place by default, after the directories you have assigned to LD_RUN_PATH
  • /etc/ld.so.cache
  • base library directories (/usr/lib and /lib)

compile mode

• control file
  • The ‘.lo’ file is the libtool object, which Libtool uses to determine what object file may be built into a shared library.

• pkg-config

gcc -o test test.c `pkg-config --libs --cflags glib-2.0`