Unix

UNIX is group of multitasking multi-user operating systems. At present there is a large number of variations of OS in this sphere - as commercial, and with the open code. Originally UNIX was developed in the late sixties by the staff of Bell Labs: Ken Thompson, Denis Ritchey and Douglas Makilroyem. The first versions of UNIX were written on the assembler and had no built-in compiler from language of the high level. Only in 1972 there was a version of a system written in Bee's language, the predecessor Si.

Main commands

The promised list of the main commands of the UNIX operating system is included below. Uppercase letters give DOS equivalents.

• logout — to Complete a session with UNIX.

• ls — to Give the list of the files which are in the current directory. Equivalent of the DIR command which is available in many operating systems. The ls command - l gives more detailed information, including the size of files, their accessory and date of creation. At 1s there are many keys, but - l - only which you will use quite often.

• rm files. DELETE: Erase (to delete) one or several files. For example, the rm file1 file2 file3 command deletes three files: filel, file2, file3. The rm command - i before removal of each file asks you to confirm the intention.

• mv old - a name new - a name. RENAME: Rename (to move) the file from old - a name to new - a name. Many complain that it is difficult for sense to remember this command because of mismatch of the reduced name (mv - rename). Correct note. Users of UNIX, however, prefer to consider that files "move" (move), but are not renamed (rename). If to consider this transaction as movement, then work in UNIX will be more intelligent.

• cp fayl1 fayl2. To LITTER: Copy fayl1 in the new file with a name fayl2.

• more file. Display the text file in a page mode. For an output of the following page it is necessary to click the space bar. Many use for this purpose the cat command and complain that her name misleads. It is, however, their wine. The cat command did not intend for an output of files to the screen; it works purely accidentally (and that is not really good). The more command is much the best means; do not trouble yourself fuss with cat. Besides, more "is not absolutely intuitive"; it is useful to remember a phrase of "show me more of this file" ("show me this file further").

• grep sample file. Show all lines in the file answering to a sample. Search is performed match case. The grep command is used for search of specific text lines in files. For example, if phones is the list of phone numbers and names, then the command of % grep John Johnson" finds phones in this list the phone number of John Johnson. Pay attention: we quoted a model of search. Quotes will never damage, but when you look for a line with a space or an asterisk, quotes are necessary.

• grep - i a sample the file. It is similar to the previous command, but the register is not considered: uppercase and lowercase letters are perceived equally.

• pwd. Show the current directory.

• cd directory. Change the current directory.

• mkdir directory. Create the new directory without files with a name the directory.

• rmdir directory. Erase (to delete) the directory with a name the directory. This directory should be empty, i.e. in it there should not be files.

• man command. Display the reference of UNIX OS on command a command.

UNIX System III

UNIX System III was the first commercial UNIX-SYSTEM. For development and support of UNIX OS the Bell Laboratories company in 1978 created the special UNIX Support Group — USG group, this group creates trial versions of OS which found application in Bell Labs and outside the company did not extend. With distribution of computers, the need for the software respectively increased, to UNIX OS the interest of the party of manufacturing companies increased. Development of computer technologies and electronic circuits, entailed sharp decrease in cost value of processors. Creation of the new mobile operating system allowed to expedite the OS installation on a new hardware platform with the minimum costs, the qualitative and modern software. The UniSoft company of one of the first began to specialize in transfer of UNIX OS on new platforms and created the version of OS which was called by UniPlus+. The UNIX option was created also by Microsoft company, the project was called by XENIX. With such great interest to UNIX and use in computers of microprocessors of Intel, Zilog, provided in the late seventies emergence of a significant amount of computers from the installed UNIX OS. The first product which is released out of limits of Bell Labs, UNIX Support Group company released in 1982, the project was called UNIX System III. Here the best qualities of the previous versions of this product were used.

Operating systems of the UNIX family

Linux

FreeBSD

Solaris