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--- notes:lpic-1_notes [2014/03/02 22:01]
smthng [102 Installation and Package Management 18%]
+++ notes:lpic-1_notes [2014/03/03 01:49] (current)
smthng [102 Installation and Package Management 18%]
@@ Line 122: / Line 122: @@
 ==Notes==
   * BIOS looks for and runs boot loader from first specified boot device.
   * Boot loader find and loads specified kernel (with specified kernel options) which loads required modules and starts system processes.
@@ Line 144: / Line 143: @@
   * Load shared libraries
   * Terms: ldd, ldconfig, /etc/ld.so.conf, LD_LIBRARY_PATH
+==Notes==
+  * Most programs on Linux use common system libraries.
+  * These can be statically linked into the program at compile-time - more disk, more memory, slower.
+  * Or can be dynamically loaded at runtime (shared libraries) - shared memory, smaller disksize, faster.
+  * //ldd// can be used to display required shared libraries for an executable
+  * Dynamically linked executables are examined at runtime by the shared object dynamic linker, //ld.so//
+  * //ldconfig// reloads shared library paths from /etc/ld.so.conf to update binary cache /etc/ld.so.cache
+  * $LD_LIBRARY_PATH env variable can also be used
 === 102.4 Use Debian package management (LCN-5 CTL-2) ===
@@ Line 150: / Line 158: @@
   * Obtain package information like version, content, dependencies, package integrity and installation status (whether or not the package is installed)
   * Terms: /etc/apt/sources.list, dpkg, dpkg-reconfigure, apt-get, apt-cache, aptitude
+==Notes==
+  * .deb package names - pkgname_version-revision_arch.deb . version is typically major.minor.patchlevel e.g ncurses4_4.2.3-9_i386.deb
+  * //dpkg// operates directly on //.deb// packages
+    * uses /var/lib/dpkg/[available|status] files to store metadata
+    * -i=install -r=remove --purge=purge
+    * -E=do not overwrite with same version or older
+    * -G=do not overwrite with older package version
+    * -l=list matching installed packages -L=list files from package
+    * -s=status of package -S=search for file in installed packages
+  * //apt-get// uses package names and sources and resolves dependencies
+    * -d=download only -s=simulate -y=assume yes
+    * install, remove, update (sources), upgrade (all packages), dist-upgrade (to new OS version)
+    * uses /etc/apt/sources.list. Lines look like <code> deb http://http.us.debian.org/debian stable main contrib non-free</code>
+  * //dselect// is a menu-based interface to //dpkg//
+  * //alien// converts other package types to .deb packages (or to rpm with -r) e.g. Slackware/generic tarball, RPM . //alien -i x.rpm//
 === 102.5 Use RPM and YUM package management (LCN-5 CTL-2) ===