... UNIXANDLINUX SYSTEM ® ® ADMINISTRATION HANDBOOK FOURTH EDITION This page intentionally left blank UNIXANDLINUX SYSTEM ® ® ADMINISTRATION HANDBOOK FOURTH EDITION Evi ... 361 xvi UNIXandLinux System Administration Handbook CHAPTER 12 SOFTWARE INSTALLATION AND MANAGEMENT 362 Installing Linuxand OpenSolaris ... Example Linux distributions 11 Example UNIX distributions 12 v vi UNIXandLinux System Administration Handbook System-specific...
... Minimal Perl: for UNIXandLinux Users 1 Introducing Minimal Perl Perl essentials 16 Perl as a (better) grep command 53 Perl as a (better) sed command 89 Perl as a (better) awk command 121 Perl as ... study Part 201 Minimal Perl: for UNIXandLinux Shell Programmers 203 Built-in functions 205 7.1 Understanding and managing evaluation context 206 Determinants and effects of evaluation context ... courseware developer, and corporate educator He has trained thousands of engineers on Unix, Linux, and Perl worldwide Tim founded Seattle’s SPUG, one of the oldest, largest, and most active Perl...
... Minimal Perl: for UNIXandLinux Users 1 Introducing Minimal Perl Perl essentials 16 Perl as a (better) grep command 53 Perl as a (better) sed command 89 Perl as a (better) awk command 121 Perl as ... study Part 201 Minimal Perl: for UNIXandLinux Shell Programmers 203 Built-in functions 205 7.1 Understanding and managing evaluation context 206 Determinants and effects of evaluation context ... courseware developer, and corporate educator He has trained thousands of engineers on Unix, Linux, and Perl worldwide Tim founded Seattle’s SPUG, one of the oldest, largest, and most active Perl...
... Many Unix utilities (grep, sed, sort, and so on) are typically used as filter programs—they read input and then write some variation on it to the output Here’s an example of the Unix sed command ... various UNIX languages and utilities But Larry also added some imaginative new features, which represent a departure from UNIX traditions The result is that Perl is a large and complex language and ... scripts that surpass the limitations of the UNIX grep command We’ll start by reviewing grep’s history, strengths, and weaknesses, and Perl’s superior features, and then we’ll show how Perl programs...
... grep-like command written in Perl and its grep counterpart: $ grep 'Linux' Welcome to your Linux system! /etc/motd $ perl -wnl -e ' /Linux/ and print;' /etc/motd Welcome to your Linux system! ... 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 ... from the standard input This allows pipelines to work as expected, as shown by this variation on the previous command: $ cat /etc/motd | perl -wnl -e ' /Linux/ and print;' Welcome to your Linux system!...
... requests the automatic switch processing that handles the command-line specifications of the old and new strings and loads the associated $old and $new variables with their contents The omission ... command to number the lines of the files: $ echo UNIX > os $ nl os UNIX # create a file $ perl -i.bak -wnl -e 's /UNIX/ Linux/ g;' os $ nl os $ nl os.bak UNIX # original os -> os.bak # original file ... provides a handy summary of the corresponding sed and perl commands that perform basic editing tasks, along with the locations where they’re discussed in this chapter Table 4.6 sed and Perl commands...
... pipeline: perl -wnl -e '-A and print;' # Example perl -wnl -e '-A and -B and print;' # Example perl -wnl -e '-A and ! -B and print;' # Example perl -wnl -e '-A and -B and -C and print;' # Example ... an Oscar and a Felix on hand In your own career, I’d advise you to develop an appreciation and an aptitude for both the quick -and- dirty and elegant -and- formal styles of programming, and to cultivate ... '( -A or -B ) and print;' # Example perl -wnl -e '( -A or -B or -C ) and print;' # Example perl -wnl -e '-A and ( -B or -C ) and -D and print;' # Example In these commands, -A, -B, and -C are placeholders...
... 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 relatives in Unix Built-in Perl function Unix relative(s) sort The Unix sort command List sorting Takes a list, and returns a sorted list reverse Linux s tac command List reversal Reverses ... the Linux ls command, so some Unix users might prefer to use the real ls On the other hand, listfile provides a good starting point for those using other OSs who wish to develop an ls-like command.13...
... string $command="fmt -$width '$file'"; # e.g., # dashed line # the heading # dashed line "fmt -62 Reuters.txt" $debug and warn "Command is:\n\t$command\n\n" and $command="set -x; $command"; # enable ... a cmd and cmd2 represent OS commands, var/$var and array/@array Shell/Perl variable names, and function a Perl function name When a Unix shell processes a command substitution, a shell of the ... code; } a In the bottom panel, cond stands for condition and cmds stands for commands both languages, the else branch is optional, allowing that keyword and its associated components to be omitted...
... raffle in which Andy contributes $3, and Dora $2: $ raffle -debug andy dora Inserting tickets for ANDY Inserting tickets for DORA # Debugging run Fishbowl contains: ANDY ANDY ANDY DORA DORA Selecting ... necessary to handle the files at hand Think of the alternative—if 100 files needed this processing, and you didn’t know how to use a loop, you would have to compose and submit 100 tr commands (one ... As you know, most Unix commands can handle multiple arguments That’s why you can get a long listing of every file that ends in txt for the current directory by using this command: ls -l *.txt...
... program's user select Unix user to monitor select ( @users ) { system "w $_"; } This script uses the who command to get the list of current users, and then a separate Perl command to isolate their ... defined $verbose and warn "Examining '$_'"; # $_ holds line foreach (split) { # split line into words, and load each into $_ /\b\w\w\w\w\b/ and print "Found '$_' in: '$_'\n" and # DOESN'T WORK! ... learn all its intricacies and applying that understanding To cite a well-known analogy from the world of Unix shell programming, it’s a lot easier to fix a misbehaving command by “adding (or subtracting)...
... obtained } $Eof and next; # handle to TYPE loop } $Eof and exit; # handle to FORMAT loop # Now construct user's command $command="ls $user_format $user_type"; # Show command, for educational ... See also masking command We distinguish between two kinds of commands A Perl command is formed by interactively typing perl and any desired arguments to the Shell A Unix command is similar, but ... space See also tab vs standard input, standard output, standard error These terms refer to the “standard” channels used on Unix systems for conveying input and output to programs, which...
... also more work (and therefore slower) when the computer encrypts and decrypts data Since SSH only uses RSA/DSA when it is This text is excerpted from Chapter of "Automating UnixandLinux Administration" ... operations ssh host1 'command1' ssh host1 'command2' ssh host2 'command3' # Finally, kill the agent and exit kill $SSH_AGENT_PID exit You could then run this script and it would prompt you for ... that is not the end of the world, and it is easy to fix (change keys) This text is excerpted from Chapter of "Automating UnixandLinux Administration" (Apress, 2003;...
... for the command If you not, a malicious user might be able to place a command with the same name earlier in the search path This text is excerpted from Chapter of "Automating UnixandLinux Administration" ... channel, you could run this command as root on your local machine: % ssh -L 25:localhost:25 user@mailserver This text is excerpted from Chapter of "Automating UnixandLinux Administration" (Apress, ... have a large number of accounts and/ or users It is much easier to create a configuration file as follows: This text is excerpted from Chapter of "Automating UnixandLinux Administration" (Apress,...
... UNIX User Interface The layers of a UNIX system UNIX Utility Programs A few of the more common UNIX utility programs required by POSIX UNIX Kernel Approximate structure of generic UNIX ... POSIX thread calls The ls Command Steps in executing the command ls type to the shell Flags for Linux clone Bits in the sharing_flags bitmap UNIX Scheduler The UNIX scheduler is based on a multilevel ... for managing the terminal UNIX I/O (1) Some of the fields of a typical cdevsw table UNIX I/O (2) The UNIX I/O system in BSD Streams An example of streams in System V The UNIX File System (1) Some...
... UNIX User Interface The layers of a UNIX system UNIX Utility Programs A few of the more common UNIX utility programs required by POSIX UNIX Kernel Approximate structure of generic UNIX kernel ... POSIX thread calls The ls Command Steps in executing the command ls type to the shell 10 Flags for Linux clone Bits in the sharing_flags bitmap 11 UNIX Scheduler The UNIX scheduler is based on a ... managing the terminal 21 UNIX I/O (1) Some of the fields of a typical cdevsw table 22 UNIX I/O (2) The UNIX I/O system in BSD 23 Streams An example of streams in System V 24 The UNIX File System (1)...
... Minimal Perl: for UNIXandLinux Users 1 Introducing Minimal Perl Perl essentials 16 Perl as a (better) grep command 53 Perl as a (better) sed command 89 Perl as a (better) awk command 121 Perl as ... study Part 201 Minimal Perl: for UNIXandLinux Shell Programmers 203 Built-in functions 205 7.1 Understanding and managing evaluation context 206 Determinants and effects of evaluation context ... courseware developer, and corporate educator He has trained thousands of engineers on Unix, Linux, and Perl worldwide Tim founded Seattle’s SPUG, one of the oldest, largest, and most active Perl...
... of these commands: I If /usr/src /linux is a symbolic link, run the rm -f linux command This removes the symbolic link I If /usr/src /linux is a directory, run the command mv linux linux.oldversion ... Red Hat® LinuxSecurityand Optimization Mohammed J Kabir Hungry Minds, Inc New York, NY G Indianapolis, IN G Cleveland, OH Red Hat® LinuxSecurityand Optimization Published ... come in handy Compiling and Installing a Custom Kernel Thanks to the Linux kernel developers, creating a custom kernel in Linux is a piece of cake A Linux kernel is modular — the features and functions...