Kernel and means of its support: the loader, sets of starting scripts, tools for support of file system, the utility is to a category system the command interpreter the user utilities and system libraries. Also it is possible to include the compiler in this section.

Interaction with modules of a kernel provides the complete set modutils. It includes commands intended for loading and a unloading of modules, definition of their dependences, such, as depmod, modprobe.

As means of support, are considered, loaders, tools for work with file systems and other system utilities. From loaders consideration two variants - classical Lilo or GRUB which has all chances to become the standard for open OS deserve.

Utilities of Linux support are incorporated in the complete set which refers to - Util-linux. In its structure set of commands for creation of disk sections (fdisk, cfdisk), managements of pumping (mkswap, swapon/swapoff), receptions of the information on system (dmesg), managements of processes and signals (kill, renice).

Means of file system support include utilities for creation, checks on integrity, reserve copying of sections HDD. For classical file system Linux - ext2fs, such set carries the name ext2fsprogs.

All these means can be received (in the form of initial codes) from corresponding section of site SGI.

Also complete sets procinfo and procps are required. The same group is adjoined with the complete set psmisc, intended for management of processes.

One more tools of support - means of start and a stop of system. They are incorporated in the complete set sysvinit. For start of full-function system scripts of initialization are required. In LFS they are incorporated in a package bootscrips, including means for start of system demons.

The direct attitude to start of system and authorization has the complete set shadow, intended for management of the user passwords.

Programs for work concern to means of support with console driver Linux. Their two - kbd and console-tools.

The most part of utilities is developed within the limits of project GNU. On the one hand, they provide the minimal user functionality of system, with another - play a service role during its assembly.

Command environment. All installation of system is carried out by commands of an environment. The interpreter of commands is necessary and for execution of starting scripts at loading system.

All-system a command environment in Linux is "bash". The environment bash possesses many advantages, but is not accomplished. The preference should be given environment Z-Shell. It also is capable to emulate POSIX-shell and consequently quite approaches as system.

All initial texts of programs are accessible in a network in archive and consequently the first, that is required for their installation are archivers and compressors. The minimal list of the first is limited to the program tar whereas compressors it is required not less than two: gzip and bzip2 as their formats are incompatible.

Further the group of sets for for manipulations with files follows. First of which and refers to - fileutils. Its structure following:

• chgrp, chmod and chown for management of attributes of files;
• cp, dd and ln for simple copying files, copying with transformation and creations of references, and also install for copying with installation of attributes;
• touch, mkdir, mkfifo and mknod - means of creation of regular files, the catalogues, special files and files of devices, accordingly;
• mv, rm, rmdir for renaming/moving of files, their removal, removal of catalogues;
• ls, dir and vdir for viewing lists of files in catalogues;
• dircolors for installation of the color scheme;
• df and du for a conclusion of the information on disk space;
• sync - for synchronization of file operations and a condition of file system.

Purpose of a set sh-utils - navigation on file systems and reception system information. In its structure - commands basename, chroot, date, echo, env, printenv, pwd.

Further the set of utilities is necessary for search of files - findutils. The main commands in its structure:

• find - practically a universal remedy for search of files and performance above found the diverse operations;
• xargs, used usually in pair with a command find, allows to apply certain commands to the list of files;
• locate - means of scanning of a database of file system with the purpose of definition of a location of the set files;
• updatedb - means of updating of a database of the file system used by a command locate.

The following block intends for work with the maintenance of text files. The first in it should be put less which is the program of paginal viewing of files.

Further - a set under a significant name textutils. Into its structure enter:

• cat - a command for creation, viewing and associations of files;
• cksum - means of check of the control sums;
• comm - means on-string comparisons of two files;
• csplit - a command for division of files into parts;
• cut - extract from the set file fragments of lines;
• expand - transformation of symbols of tabulation inside of a text file in blanks;
• fmt - formatting of paragraphs of a text file;
• fold - splitting of a file into lines of the set length;
• head - a conclusion of the first (10 by default) lines of a file;
• join - merge of lines of two files in the general field;
• md5sum - too from area of the control sums;
• nl - numbering of lines of the set file;
• od - viewing of a file a kind octal (by default) or other other codes;
• paste - on-string association of files;
• pr - splitting of files into pages and columns;
• ptx - generation of an index of a contained file;
• sort - on-string sorting of a contained file;
• split - splitting of a file into parts of the set size, quantity of lines and on a line-pattern;
• sum - calculation of the control sum and quantity of blocks in a file;
• tac - a conclusion of a contained file behind beforehand;
• tail - a conclusion of several (ten by default) last lines of a file;

Two complementary sets - diffutils and patch. The first is intended for comparison of files with fixing their distinctions. The second - for modification in conformity with these most fixed distinctions.

Set grep. Programs entering into its structure grep, fgrep and egrep are intended for search of text fragments (patterns) in files.

Sets "ed", "gawk" and sed are intended for rather complex text processing, representing text editors.

And last means having some attitude to texts - gettext, toolkit for the organization of international support (so-called NLS - National Languages Support).

Network opportunities of base system are provided with two sets - netkit-base and net-tools. In the first - a demon inetd, the Internet responsible for service in general, and a command ping for check of access to units of a network. Commands of a set net-tools define a configuration of a network (ifconfig), domain names, names of hosts, etc.

At last, group of sets, last under the account, but not on value, - systems of the documentation. Those in Linux it is widely used two - traditional for Unix man-pages and developed within the limits of GNU system info. They - complementary though under the maintenance and essentially block each other.

Basically it is system divided libraries. The user very seldom should deal with them, but without them functioning of system is practically impossible. Certainly, many appendices can be connected with divided libraries statically. However assembly of own system without them is impracticable.

The main library in Linux is glibc. Except for it the terminal library ncurses is required. And still - the toolkit for linkage of programs with library functions libtool is required also.

At last, necessary to collect all listed above together are means of assembly. First of all - the compiler of language C on which the most part of OS Linux and programs for it gcc is written.

Further - means of maintenance of compilation (assembler, etc.), incorporated in two sets bin86 and binutils. Then - the program of compilation management, make, and it is close with it the connected utilities autoconf for construction of means automatic config at assembly, and automake for automation of creation of the make-files describing process of compilation. Besides practically necessary appear also the lexical analyzer flex, a parser bison and the macroprocessor m4. In some cases for assembly of programs the interpreter of language perl is required.