Unix I Documentation Release 1.0
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CS101 Lecture 9
How do you copy/move/rename/remove files? How do you create a directory ? What is redirection and piping? Readings: See CCSO’s Unix pages and 9-2 cp option file1 file2 First Version cp file1 file2 file3 … dirname Second Version This is one version of the cp command. file2 is created and the contents of file1 are copied into file2. If file2 already exits, it This version copies the files file1, file2, file3,… into the directory will be replaced with a new one. dirname. where option is -i Protects you from overwriting an existing file by asking you for a yes or no before it copies a file with an existing name. -r Can be used to copy directories and all their contents into a new directory 9-3 9-4 cs101 jsmith cs101 jsmith pwd data data mp1 pwd mp1 {FILES: mp1_data.m, mp1.m } {FILES: mp1_data.m, mp1.m } Copy the file named mp1_data.m from the cs101/data Copy the file named mp1_data.m from the cs101/data directory into the pwd. directory into the mp1 directory. > cp ~cs101/data/mp1_data.m . > cp ~cs101/data/mp1_data.m mp1 The (.) dot means “here”, that is, your pwd. 9-5 The (.) dot means “here”, that is, your pwd. 9-6 Example: To create a new directory named “temp” and to copy mv option file1 file2 First Version the contents of an existing directory named mp1 into temp, This is one version of the mv command. file1 is renamed file2. where option is -i Protects you from overwriting an existing file by asking you > cp -r mp1 temp for a yes or no before it copies a file with an existing name. -
Common Commands Cheat Sheet by Mmorykan Via Cheatography.Com/89673/Cs/20411
Common Commands Cheat Sheet by mmorykan via cheatography.com/89673/cs/20411/ Scripting Scripting (cont) GitHub bash filename - Runs script sleep value - Forces the script to wait value git clone <url > - Clones gitkeeper url Shebang - "# !bi n/b ash " - First line of bash seconds git add <fil ena me> - Adds the file to git script. Tells script what binary to use while [[ condition ]]; do stuff; done git commit - Commits all files to git ./file name - Also runs script if [[ condition ]]; do stuff; fi git push - Pushes all git files to host # - Creates a comment until [[ condition ]]; do stuff; done echo ${varia ble} - Prints variable words=" h ouse dogs telephone dog" - Package / Networking hello_int = 1 - Treats "1 " as a string Declares words array dnf upgrade - Updates system packages Use UPPERC ASE for constant variables for word in ${words} - traverses each dnf install - Installs package element in array Use lowerc ase _wi th_ und ers cores for dnf search - Searches for package for counter in {1..10} - Loops 10 times regular variables dnf remove - Removes package for ((;;)) - Is infinite for loop echo $(( ${hello _int} + 1 )) - Treats hello_int systemctl start - Starts systemd service as an integer and prints 2 break - exits loop body systemctl stop - Stops systemd service mktemp - Creates temporary random file for ((count er=1; counter -le 10; counter ++)) systemctl restart - Restarts systemd service test - Denoted by "[[ condition ]]" tests the - Loops 10 times systemctl reload - Reloads systemd service condition -
A Brief Introduction to Unix-2019-AMS
Brief Intro to Linux/Unix Brief Intro to Unix (contd) A Brief Introduction to o Brief History of Unix o Compilers, Email, Text processing o Basics of a Unix session o Image Processing Linux/Unix – AMS 2019 o The Unix File System Pete Pokrandt o Working with Files and Directories o The vi editor UW-Madison AOS Systems Administrator o Your Environment [email protected] o Common Commands Twitter @PTH1 History of Unix History of Unix History of Unix o Created in 1969 by Kenneth Thompson and Dennis o Today – two main variants, but blended o It’s been around for a long time Ritchie at AT&T o Revised in-house until first public release 1977 o System V (Sun Solaris, SGI, Dec OSF1, AIX, o It was written by computer programmers for o 1977 – UC-Berkeley – Berkeley Software Distribution (BSD) linux) computer programmers o 1983 – Sun Workstations produced a Unix Workstation o BSD (Old SunOS, linux, Mac OSX/MacOS) o Case sensitive, mostly lowercase o AT&T unix -> System V abbreviations 1 Basics of a Unix Login Session Basics of a Unix Login Session Basics of a Unix Login Session o The Shell – the command line interface, o Features provided by the shell o Logging in to a unix session where you enter commands, etc n Create an environment that meets your needs n login: username n Some common shells n Write shell scripts (batch files) n password: tImpAw$ n Define command aliases (this Is my password At work $) Bourne Shell (sh) OR n Manipulate command history IHateHaving2changeMypasswordevery3weeks!!! C Shell (csh) n Automatically complete the command -
The Linux Command Line
The Linux Command Line Fifth Internet Edition William Shotts A LinuxCommand.org Book Copyright ©2008-2019, William E. Shotts, Jr. This work is licensed under the Creative Commons Attribution-Noncommercial-No De- rivative Works 3.0 United States License. To view a copy of this license, visit the link above or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042. A version of this book is also available in printed form, published by No Starch Press. Copies may be purchased wherever fine books are sold. No Starch Press also offers elec- tronic formats for popular e-readers. They can be reached at: https://www.nostarch.com. Linux® is the registered trademark of Linus Torvalds. All other trademarks belong to their respective owners. This book is part of the LinuxCommand.org project, a site for Linux education and advo- cacy devoted to helping users of legacy operating systems migrate into the future. You may contact the LinuxCommand.org project at http://linuxcommand.org. Release History Version Date Description 19.01A January 28, 2019 Fifth Internet Edition (Corrected TOC) 19.01 January 17, 2019 Fifth Internet Edition. 17.10 October 19, 2017 Fourth Internet Edition. 16.07 July 28, 2016 Third Internet Edition. 13.07 July 6, 2013 Second Internet Edition. 09.12 December 14, 2009 First Internet Edition. Table of Contents Introduction....................................................................................................xvi Why Use the Command Line?......................................................................................xvi -
Student Number: Surname: Given Name
Computer Science 2211a Midterm Examination Sample Solutions 9 November 20XX 1 hour 40 minutes Student Number: Surname: Given name: Instructions/Notes: The examination has 35 questions on 9 pages, and a total of 110 marks. Put all answers on the question paper. This is a closed book exam. NO ELECTRONIC DEVICES OF ANY KIND ARE ALLOWED. 1. [4 marks] Which of the following Unix commands/utilities are filters? Correct answers are in blue. mkdir cd nl passwd grep cat chmod scriptfix mv 2. [1 mark] The Unix command echo HOME will print the contents of the environment variable whose name is HOME. True False 3. [1 mark] In C, the null character is another name for the null pointer. True False 4. [3 marks] The protection code for the file abc.dat is currently –rwxr--r-- . The command chmod a=x abc.dat is equivalent to the command: a. chmod 755 abc.dat b. chmod 711 abc.dat c. chmod 155 abc.dat d. chmod 111 abc.dat e. none of the above 5. [3 marks] The protection code for the file abc.dat is currently –rwxr--r-- . The command chmod ug+w abc.dat is equivalent to the command: a. chmod 766 abc.dat b. chmod 764 abc.dat c. chmod 754 abc.dat d. chmod 222 abc.dat e. none of the above 2 6. [3 marks] The protection code for def.dat is currently dr-xr--r-- , and the protection code for def.dat/ghi.dat is currently -r-xr--r-- . Give one or more chmod commands that will set the protections properly so that the owner of the two files will be able to delete ghi.dat using the command rm def.dat/ghi.dat chmod u+w def.dat or chmod –r u+w def.dat 7. -
Unix Security Overview: 1
CIS/CSE 643: Computer Security (Syracuse University) Unix Security Overview: 1 Unix Security Overview 1 User and Group • Users – root: super user (uid = 0) – daemon: handle networks. – nobody: owns no files, used as a default user for unprivileged operations. ∗ Web browser can run with this mode. – User needs to log in with a password. The encrypted password is stored in /etc/shadow. – User information is stored in /etc/passwd, the place that was used to store passwords (not anymore). The following is an example of an entry in this file. john:x:30000:40000:John Doe:/home/john:/usr/local/bin/tcsh • Groups – Sometimes, it is more convenient if we can assign permissions to a group of users, i.e. we would like to assign permission based on groups. – A user has a primary group (listed in /etc/passwd), and this is the one associated to the files the user created. – Any user can be a member of multiple groups. – Group member information is stored in /etc/group % groups uid (display the groups that uid belongs to) – For systems that use NIS (Network Information Service), originally called Yellow Page (YP), we can get the group information using the command ypcat. % ypcat group (can display all the groups and their members) 2 File Permissions • File Permissions – The meaning of the permission bits in Unix. ∗ Owner (u), Group (g), and Others (o). ∗ Readable (r), Writable (w), and Executable (x). ∗ Example: -rwxrwxrwx (777) • Permissions on Directories: – r: the directory can be listed. – w: can create/delete a file or a directory within the directory. -
File Security Lock Down Your Data
File Security Lock Down Your Data Brian Reames January 22, 2012 Table of Contents 1.0 Basic Linux Permissions...............................................................................................................4 1.1 Determining Permissions……………………………………………………………………..................... 5 1.2 File Permissions vs. Directory Permissions………………………………………………….............. 6 1.3 Changing Permissions………………………………………………………………………….................... 7 1.3.1 Symbolic Method…………………………………………………………………….................... 8 1.3.2 Octal Method………………………………………………………………………..................... 10 1.3.3 Changing Permissions Graphically……………………………………………….............. 12 1.4 Examples of Unintentional Access…………………………………………………………................. 13 2.0 Setting Default Permissions………………………………………………………………………...................... 15 2.1 Common umask Settings……………………………………………………………………....................17 3.0 Advanced Linux Permissions……………………………………………………………………….................... 18 3.1 Special Permission: setuid………………………………………………………………….....................19 3.1.1 Setting the setuid Permission……………………………………………………................ 20 3.1.2 Caution Regarding setuid………………………………………………………….................22 3.2 Special Permission setgid……………………………………………………………………................... 23 3.2.1 setgid on a File……………………………………………………………………...................... 24 3.2.2 setgid on a Directory……………………………………………………………….................. 25 3.2.3 Caution Regarding setgid…………………………………………………………................. 28 3.3 Special Permission: sticky bit……………………………………………………………….................. -
Unix (And Linux)
AWK....................................................................................................................................4 BC .....................................................................................................................................11 CHGRP .............................................................................................................................16 CHMOD.............................................................................................................................19 CHOWN ............................................................................................................................26 CP .....................................................................................................................................29 CRON................................................................................................................................34 CSH...................................................................................................................................36 CUT...................................................................................................................................71 DATE ................................................................................................................................75 DF .....................................................................................................................................79 DIFF ..................................................................................................................................84 -
APPENDIX a Aegis and Unix Commands
APPENDIX A Aegis and Unix Commands FUNCTION AEGIS BSD4.2 SYSS ACCESS CONTROL AND SECURITY change file protection modes edacl chmod chmod change group edacl chgrp chgrp change owner edacl chown chown change password chpass passwd passwd print user + group ids pst, lusr groups id +names set file-creation mode mask edacl, umask umask umask show current permissions acl -all Is -I Is -I DIRECTORY CONTROL create a directory crd mkdir mkdir compare two directories cmt diff dircmp delete a directory (empty) dlt rmdir rmdir delete a directory (not empty) dlt rm -r rm -r list contents of a directory ld Is -I Is -I move up one directory wd \ cd .. cd .. or wd .. move up two directories wd \\ cd . ./ .. cd . ./ .. print working directory wd pwd pwd set to network root wd II cd II cd II set working directory wd cd cd set working directory home wd- cd cd show naming directory nd printenv echo $HOME $HOME FILE CONTROL change format of text file chpat newform compare two files emf cmp cmp concatenate a file catf cat cat copy a file cpf cp cp Using and Administering an Apollo Network 265 copy std input to std output tee tee tee + files create a (symbolic) link crl In -s In -s delete a file dlf rm rm maintain an archive a ref ar ar move a file mvf mv mv dump a file dmpf od od print checksum and block- salvol -a sum sum -count of file rename a file chn mv mv search a file for a pattern fpat grep grep search or reject lines cmsrf comm comm common to 2 sorted files translate characters tic tr tr SHELL SCRIPT TOOLS condition evaluation tools existf test test -
Laboratory 1: Getting Familiar with GLUE UNIX Programming Environment
Laboratory 1: Getting Familiar with GLUE UNIX Programming Environment Lecture notes: 1. Scope of the course Prerequisite for ENEE 150 (see the last page for more details), very basic skills in programming and UNIX. a. Principles of programming and software development. b. C will be used as the programming language to illustrate the concepts. c. Basic skills in UNIX operating systems. 2. How to program (or develop software package in the future) a. Document everything you do in each of the following steps. b. Understand the project/problem requirements c. Develop algorithm (the way or method to solve the problem) d. Plan for the implementation of your algorithm (data structure, etc.) e. Write the programming (C, C++, Java, Matlab, etc.) f. Compile the program (gcc or cc in GLUE UNIX for C codes. Compiler is the interpreter that translates the program written in the so-called high level programming languages like C by human, who call themselves programmers, and understandable by human to the low level language that the computer understands.) g. Execute, test, and debug your program on sample data. h. Go back to step d. (modify your code) if necessary (programming or syntax bugs). i. Go back to step c. or step b. if there are serious problems (algorithm or logic bugs). j. Confirm that all the project requirements are met. (output format, etc.) 3. What is UNIX? a. UNIX is an operating system, like windows, which is a complex set of computer codes that manages the activities and resources of the computer. It is very popular in universities and colleges. -
ANSWERS ΤΟ EVEN-Numbered
8 Answers to Even-numbered Exercises 2.1. WhatExplain the following unexpected are result: two ways you can execute a shell script when you do not have execute permission for the file containing the script? Can you execute a shell script if you do not have read permission for the file containing the script? You can give the name of the file containing the script as an argument to the shell (for example, bash scriptfile or tcsh scriptfile, where scriptfile is the name of the file containing the script). Under bash you can give the following command: $ . scriptfile Under both bash and tcsh you can use this command: $ source scriptfile Because the shell must read the commands from the file containing a shell script before it can execute the commands, you must have read permission for the file to execute a shell script. 4.3. AssumeWhat is the purpose ble? you have made the following assignment: $ person=zach Give the output of each of the following commands. a. echo $person zach b. echo '$person' $person c. echo "$person" zach 1 2 6.5. Assumengs. the /home/zach/grants/biblios and /home/zach/biblios directories exist. Specify Zach’s working directory after he executes each sequence of commands. Explain what happens in each case. a. $ pwd /home/zach/grants $ CDPATH=$(pwd) $ cd $ cd biblios After executing the preceding commands, Zach’s working directory is /home/zach/grants/biblios. When CDPATH is set and the working directory is not specified in CDPATH, cd searches the working directory only after it searches the directories specified by CDPATH. -
UNIX Logout ^D Or Exit Man Command Man -K Keyword Ls Ls -A Ls -L Ls -G Cp
UNIX Reference Page 1 of 3 UNIX Reference Computing and Information Technology Basic Commands Log out of system logout Exit current shell ^D or exit Online Documentation See online manual page man command Search for a manual page man -k keyword Files List filenames ls - with hidden files ls -a - with file permissions ls -l - with group ownership ls -g Copy a file cp old new Copy a file to dirname cp file dirname Rename (move) a file mv old new Remove (delete) a file rm file Append file1 to file2 cat file1 >> file2 Home directory ~ Home directory of user ~user Change file permissions chmod (ugo +-rwx) file Wild cards - single character ? - multiple characters * - range (a and b are single [a-b] characters) File Editors Emacs emacs file vi vi file pico pico file Using less View file less file next line <Return> next page <Space> search for pattern /pattern next occurrence n next file :n help :h http://wings.buffalo.edu/computing/Documentation/unix/ref/unixref.html 9/13/2004 UNIX Reference Page 2 of 3 quit :q Directories Make a directory mkdir dirname Change directories cd dirname Remove a directory rmdir dirname See thecurrent directory name pwd Current directory . Parent of the current directory .. Root of the file system / Printing Print file to default printer lpr file (Bell 101) Print file to a printer at another lpr -Pprintername site file View printer queue lpq -Pprinter Remove job number jn lprm jn View job turnaround time prstat Job and Process Control Run job j in the background j& List jobs jobs Connect to job number n %n List