minimal perl for unix and linux users

... Bauer Automating UNIX and Linux Administration CYAN MAGENTA YELLOW BLACK PANTONE 123 CV ISBN 1-59059-212-3 9 781590 592120 54999 6 89253 15123 5 www.apress.com Automating UNIX and Linux Administration ... ask for the key once ssh-add # Now, perform a bunch of SSH operations ssh host1 'command1' ssh host1 'command2' ssh host2 'command3' # Finally, kill the agent and ... systems to become more reliable and efficient every day. Kirk Bauer US $49.99 Shelve in Networking/UNIX/Linux User level: Intermediate–Advanced forums.apress.com FOR PROFESSIONALS BY PROFESSIONALS

Ngày tải lên: 08/08/2014, 21:21

... on the system for each user who needs to run commands as root. 2.12.1 Preparing for Common Accounts The setup is actually very simple. You generate a key pair for each user and then list ... the system and nothing more. no-port-forwarding,command="/sbin/reboot",no-pty ssh-rsa AB YZ Whoever possesses the specified private key cannot open an interactive shell or forward ports. ... Chapter 2 of "Automating Unix and Linux Administration" (Apress, 2003; ISBN: 1-59059-212-3). Using SSH to Securely Automate System Administration 27 2.11.3 Port Forwarding There are plenty

Ngày tải lên: 08/08/2014, 21:21

... v, w, x and y are symbolic Finally we see two function handles and two inline objects, corresponding to the pairs of anonymousfunctions and inline functions The command whos shows information ... variable and press ENTERor RETURN MATLAB commands expect particular classes of data as input, and it is tant to know what class of data is expected by a given command; the help text for acommand usually ... select Copy, then right-click in the Command Window and select Paste, whereupon the command you selected will appear at the command prompt and be ready for editing As we described in Recovering

Ngày tải lên: 09/08/2014, 12:22

... 1/3 Sums and Products Finite numerical sums and products can be computed easily using the vector capabil-ities of MATLAB and the commands sum and prod For example, You can do finite and infinite ... techniques for creating and modifying images and sounds ✓ For most types of graphs we describe below, there is a command like plot that draws the graph from numerical data, and a command like ezplot ... these commands, as well as some ofthe other most commonly used plotting commands Then we will discuss methods forcustomizing and manipulating graphics Finally, we will introduce some commandsand techniques

Ngày tải lên: 09/08/2014, 12:22

... variables ✓ Like for and the other programming commands you will encounter, if and its associated commands can be used in the Command Window Doing socan be useful for practice with these commands, but ... first command defines an empty structure, and the subsequent commands addfields to it ✓ MATLAB also has signed and unsigned integer data types; see the online help for int32 and uint32, for example. ... command between the else and end statements On the other hand, if x is negative, then MATLAB skips to the else statement and executes the succeeding command, setting y equal to -x As with a forloop,

Ngày tải lên: 09/08/2014, 12:22

... model for the crane We want to experiment with various possibilities for w(t) and see what effect these have on the measure of “swinging,” θ(t) Let’s use meters and seconds as our units and take ... simfrom the command line or within an M-file The simplest form of this commandjust runs the model with the existing parameters But one can also use this command to set the time interval and to send ... pushbutton1_Callback(hObject, eventdata, handles) % hObject handle to pushbutton2 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA)

Ngày tải lên: 09/08/2014, 12:22

... an n × k matrix of random numbers and then perform the same operations as above on each entry of the matrix to obtain a matrixwith entries 1 for bets the casino won and −1 for bets it lost Finally ... (including itself) and produces anoutput, which is divided among the various sectors (For example, agriculture pro-duces food for home consumption and for export, but also seeds and new livestockwhich ... between u0and u1 there is a cycle of period 2; between u1 and u2thereis cycle of period 4; and in general, between u k and u k+1there is a cycle of period 2k+1 In fact one knows that, at least for

Ngày tải lên: 09/08/2014, 12:22

... 0 to time 4, using boundary temperatures 15 and 25, and an initial temperature distribution of 15 for x<0 and 25 for x>0. We replace u(x, t) for fixed t by the vector u of values of u(x, ... x ≤ 5 from time 0 to time 4, using boundary temperatures 15 and 25, and an initial temperature distribution of 15 for x<0 and 25 for x>0. You can imagine that two separate wires of length ... can use for the derivatives, and this method can be refined by using more accurate approximations, especially for the t derivative.) Thus if, for a particular n, we know the values of u n j for all

Ngày tải lên: 09/08/2014, 12:22

... as input two expressions f and g (given either as symbolic expressions or as strings) and two numbers a and b, plots the functions f and g between x = a and x = b, and shades the region in between ... the M-file for common mistakes and syntax errors and prints out a report specifying where potential problems are located. (You can do the same thing from the Command Window with the command mlint ... the wrong type of input for the plotting command chosen. SOLUTION: Carefully follow the examples in the help lines of the plotting command, and pay attention to the error and warning messages.

Ngày tải lên: 09/08/2014, 12:22

... on a random number chosen between 0 and 1 If the random number is less than 0.338, the expression evaluates to 1 and Tony is credited with a hit; otherwise, the expression evaluates to 0 and Tony ... the commands above yourself to see the flags in color.Then you can run the commands below to see a movie transforming the French flaginto the Italian flag Trang 16Below is a series of commands that ... 500 random numbers into this expression at once andsum the results, dividing by 500 to get his batting average for the year The following function does just this, allowing more generally for n

Ngày tải lên: 09/08/2014, 12:22

... Random-number generator; creates arrays of random numbers between 0 and 1 randn Normal random-number generator; creates arrays of normal random numbers with mean 0 and variance 1 rank Gives the rank ... used for defining vectors and matrices Type help colon for more information , Separates elements of a row of a matrix, or arguments to a command Can also be used to separate commands ... the axes and tick marks bar Draws a bar graph 295 bar([2, 7, 1.5, 6]) Clears axes... important Simulink commands and blocks Though MATLAB does not distinguish between commands and functions,

Ngày tải lên: 09/08/2014, 12:22

... Trang 1Case Study 1: UNIX and LINUXChapter 10 10.1 History of unix 10.2 Overview of unix 10.3 Processes in unix 10.4 Memory management in unix 10.5 Input/output in unix 10.6 The unix file system ... calls Trang 10The ls CommandSteps in executing the command ls type to the shell Trang 11Flags for Linux cloneBits in the sharing_flags bitmap Trang 12UNIX SchedulerThe UNIX scheduler is based ... 10.7 Security in unix Trang 2The layers of a UNIX system User Interface Trang 3UNIX Utility ProgramsA few of the more common UNIX utility programs required by POSIX Trang 4UNIX KernelApproximate

Ngày tải lên: 18/10/2014, 15:30

... Trang 1Study UNIX and LINUXTrang 2The layers of a UNIX system User Interface Trang 3UNIX Utility ProgramsA few of the more common UNIX utility programs required by POSIX Trang 4UNIX KernelApproximate ... calls Trang 10The ls CommandSteps in executing the command ls type to the shell Trang 11Flags for Linux cloneBits in the sharing_flags bitmap Trang 12UNIX SchedulerThe UNIX scheduler is based ... offset Trang 17Paging in UNIXThe core map in 4BSD The core map has an entry for each page Trang 18Paging in Linux (1)Linux uses three-level page tables Trang 19Paging in Linux (2)Operation of the

Ngày tải lên: 24/10/2014, 10:54

... gratitude for all the good times we’ve had together brief contents Part Minimal Perl: for UNIX and Linux Users 1 Introducing Minimal Perl Perl essentials 16 Perl as a (better) grep command 53 Perl ... Part Minimal Perl: for UNIX and Linux Users 1 Introducing Minimal Perl 1.1 A visit to Perlistan 3 Sometimes you need a professional guide 1.2 Perl can be simple 1.3 About Minimal Perl What Minimal ... about how Minimal Perl fits into its associated cultures CHAPTER INTRODUCING MINIMAL PERL How does Minimal Perl relate to Unix and standard Perl? Minimal Perl emphasizes the features of Perl that...

Ngày tải lên: 25/03/2014, 10:27

... Explanation /perl/ Looks for a match with perl in $_ Matches perl in $_ m :perl: Same, except uses different delimiters Matches perl in $_ $data =~ /perl/ i Looks for a match Matches perl PERL Perl ... Unix and Perl commands for common grepping activities Unix command Perl counterpart Type of task Section grep 'RE' F perl -wnl -e '/RE/ and print;' F Show matching lines 3.3.1 grep -v 'RE' F perl ... after consulting man ascii: 104 LHS and RHS, respectively, stand for left- and right-hand-side, and DQ stands for double quotes CHAPTER PERL AS A (BETTER) sed COMMAND ...

Ngày tải lên: 06/08/2014, 03:20

... of AWK and Perl next NOTE 5.2 AWK is totally AWKsome, but Perl is even better; it’s Perlicious! COMPARING BASIC FEATURES OF awk AND PERL This section provides an overview of how AWK and Perl compare ... $total, as in $total += $_ CHAPTER PERL AS A (BETTER) awk COMMAND Table 5.8 AWK and Perl programs for simple tasks AWK a Perl b Explanation

Ngày tải lên: 06/08/2014, 03:20

... '-A and ! -B and print;' # Example perl -wnl -e '-A and -B and -C and print;' # Example perl -wnl -e '( -A or -B ) and print;' # Example perl -wnl -e '( -A or -B or -C ) and print;' # Example perl ... Then Perl commands, having forms such as these, could be added as the filtering stage in the pipeline: perl -wnl -e '-A and print;' # Example perl -wnl -e '-A and -B and print;' # Example perl ... use a special kind of find | perl pipeline for filtering out undesirable arguments for Unix utilities, and how to use Unix utilities for validating arguments for Perl programs 6.4 PROCESSING...

Ngày tải lên: 06/08/2014, 03:20

... Table 7.7 The rand function Typical invocation formats $random_tiny_number=rand; $random_larger_number=rand N; $random_element=$some_array[ rand @some_array ]; Example Explanation $num=rand; Assigns ... nearest relative in Unix or the Shell Table 7.8 Useful Perl functions for lists, and their nearest relatives in Unix Built-in Perl function Unix relative(s) sort The Unix sort command List sorting ... similarities and differences in how data flows between commands and functions 7.3.1 Comparing Unix pipelines and Perl functions Although there are distinct similarities between Unix command pipelines and...

Ngày tải lên: 06/08/2014, 03:20

... back-quote syntax for command substitution, of the form $(command) INTERPOLATING COMMAND OUTPUT INTO SOURCE CODE 269 Table 8.6 Command substitution/interpolation in the Shell and Perl Shell a Perl Explanation ... separated records a cmd and cmd2 represent OS commands, var/$var and array/@array Shell /Perl variable names, and function a Perl function name When a Unix shell processes a command substitution, a ... submit a command to the OS-dependent command interpreter (/bin/sh on Unix) for execution 18 See http://TeachMePerl.com/DQs_in_shell_vs _perl. html for further details EXECUTING OS COMMANDS USING...

Ngày tải lên: 06/08/2014, 03:20

... quality value The Shell’s for loop is similar to Perl s foreach loop, not Perl s for loop LOOPING WITH for Although the Shell’s for is like Perl s foreach, Perl does have a for loop of its own, derived ... variable The syntax for the Shell’s for loop is shown in table 10.5 alongside that of its Perl counterpart, foreach Table 10.5 The Shell’s for loop and Perl s foreach loop Shell a Perl for var in LIST ... $index=rand @fortunes; # select random index CHAPTER LIST VARIABLES 27 28 29 30 31 32 printf $fortunes[ $index ]; # print random fortune delete $fortunes[ $index ]; # mark fortune undefined @fortunes=grep...

Ngày tải lên: 06/08/2014, 03:20