background preloader

Unix

Facebook Twitter

Csh(1. Name tcsh - C shell with file name completion and command line editing Synopsis tcsh [-bcdefFimnqstvVxX] [-Dname[=value]] [arg ...] tcsh -l Description tcsh is an enhanced but completely compatible version of the Berkeley UNIX C shell, csh(1).

csh(1

Argument list processing If the first argument (argument 0) to the shell is '-' then it is a login shell. The rest of the flag arguments are interpreted as follows: Scripts.pdf. [Chapter 1] 1.2 A Stream Editor. Sed is a "non-interactive" stream-oriented editor.

[Chapter 1] 1.2 A Stream Editor

It is stream-oriented because, like many UNIX programs, input flows through the program and is directed to standard output. ( vi , for instance, is not stream-oriented. Nor are most DOS applications.) Input typically comes from a file but can be directed from the keyboard.[2] Output goes to the terminal screen by default but can be captured in a file instead. Sed works by interpreting a script specifying the actions to be performed. AWK one liners. One great blunder of Unix developers was that they did not integrated AWK into shell.

AWK one liners

Actually development team which developed AWK technically was heads above shell developers before David Korn. David Korn was a talented developer, but he came too late to change the situation. Later the attempt to integrate shell and AWk was attempted in Perl, which can be used instead of AWK in some cases. Using Perl in your SystemVerilog HDL Design Flow.

Today is: How to use Perl in your SystemVerilog HDL Design Flow?

Using Perl in your SystemVerilog HDL Design Flow

Anyone who designs with SystemVerilog HDL has probably grown tired of generating module instantiations in a hierarchical design, or creating a new top level or lower level SystemVerilog HDL module. I have generated a few Perl Scripts that will automatically generate the module instantiations, top level module, and lower level module for you. These Perl Scripts can be invoked from within VI/VIM/GVIM, or a DOS Command Window. If you invoke them from within VI, the script output will be printed in the current file. Vi Cheat Sheet. Success Tips. Cygwin Tips by zzapper Linux Like Environment for Windows. Best of VIM Tips, gVIM's Key Features zzapper. Russian Alphabet - Russian Language Lesson 1. The Russian alphabet is easy to learn!

Russian Alphabet - Russian Language Lesson 1

Learning the alphabet is the first step to learning the Russian language. Even if you don't plan to learn the language, knowing the alphabet is great for travelling because you can read all the street and shop signs. It may seem daunting to learn a new alphabet, but it is relatively easy. In fact, the great thing about Russian is that almost all words can be sounded out as they are written. Unlike English where the pronunciation of a word may not be clear from its written form. Either before or after this lesson we recommend you print the alphabet table, and stick it up next to the computer (or around the house), to help you with the following lessons. The Russian alphabet is also known as the Cyrillic alphabet.

Now let's have a look at these letters in detail. Russian letters that are (almost) the same. How do I shuffle an array? Random array sorting. Perl HowTo. Recipe 4.17. Randomizing an Array. Problem You want to shuffle the elements of an array randomly.

Recipe 4.17. Randomizing an Array

The obvious application is writing a card game, where you must shuffle a deck of cards, but it is equally applicable to any situation where you want to deal with elements of an array in a random order. Solution Swap each element in the array with another randomly selected, element: # fisher_yates_shuffle( \@array ) : generate a random permutation # of @array in place sub fisher_yates_shuffle { my $array = shift; my $i; for ($i = @$array; --$i; ) { my $j = int rand ($i+1); next if $i == $j; @$array[$i,$j] = @$array[$j,$i]; } } fisher_yates_shuffle( \@array ); # permutes @array in place Or, pick a random permutation using the code in Example 4.4 : Using the Perl rand() function. Introduction The rand() function is used to generate random numbers.

Using the Perl rand() function

By default it generates a number between 0 and 1, however you can pass it a maximum and it will generate numbers between 0 and that number. Example 1. Between 0 and 1. Perl Basics In Pictures: Generate random numbers. Www.astro.soton.ac.uk/unixtut/sc4.pdf. Perl For Loop Tutorial - Control Structures in Perl, Learn How to Use a For Loop. As we've discussed, Perl's for loop, or for statement, is used to loop through a designated block of code until a specific condition is met.

Perl For Loop Tutorial - Control Structures in Perl, Learn How to Use a For Loop

Let's look at an example of Perl's for loop in action and break down exactly how it works, step by step. for ($count = 10; $count >= 1; $count--) { print "$count "; } print "Blastoff. \n"; Running this simple Perl script produces the following output: Writing to a File in Perl. Let's take the same data file we worked with while learning to read a file in Perl, and we'll write to it this time.

Writing to a File in Perl

In order to write to a file in Perl, you must open a filehandle and point it at the file you're writing. If you're using Unix, Linux, or a Mac, you might also need to double check your file permissions to see if your Perl script is allowed to write to the data file. #! Faq4. <div class="noscript"> <p> <strong>Please note: Many features of this site require JavaScript. You appear to have JavaScript disabled, or are running a non-JavaScript capable web browser. </strong> </p> <p> To get the best experience, please enable JavaScript or download a modern web browser such as <a href=" Explorer 8</a>, <a href=" <a href=" or <a href=" Chrome</a>. </p> </div> Data: Numbers Why am I getting long decimals (eg, 19.9499999999999) instead of the numbers I should be getting (eg, 19.95)? English Tenses Chart.

Www-cs.canisius.edu/ONLINESTUFF/UNIX/shellprogramming.html. PLEAC-Perl. Home - Use grep Command In Linux / UNIX [ Examples ] How do I use grep command on Linux, Apple OS X, and Unix-like operating systems?

Use grep Command In Linux / UNIX [ Examples ]

Can you give me a simple examples of the grep command? The grep command is used to search text or searches the given file for lines containing a match to the given strings or words. By default, grep displays the matching lines. Use grep to search for lines of text that match one or many regular expressions, and outputs only the matching lines. grep is considered as one of the most useful commands on Linux and Unix-like operating systems. Did you know? The name, "grep", derives from the command used to perform a similar operation, using the Unix/Linux text editor ed: g/re/p The grep command syntax The syntax is as follows: Linux and UNIX find command help. Quick links About findSyntaxExamplesRelated commands Linux and Unix main page About find find searches for files in a directory hierarchy.

Syntax find [-H] [-L] [-P] [-D debugopts] [-Olevel] [path...] Linux and Unix commands, information, and help. Mommy, I found it! — 15 Practical Linux Find Command Examples. Apart from the basic operation of looking for files under a directory structure, you can also perform several practical operations using find command that will make your command line journey easy. In this article, let us review 15 practical examples of Linux find command that will be very useful to both newbies and experts. First, create the following sample empty files under your home directory to try some of the find command examples mentioned below. # vim create_sample_files.sh touch MybashProgram.sh touch mycprogram.c touch MyCProgram.c touch Program.c mkdir backup cd backup touch MybashProgram.sh touch mycprogram.c touch MyCProgram.c touch Program.c # chmod +x create_sample_files.sh # .

Example uses of the Linux Command find. The following examples illustrate typical uses of the command find for finding files on a computer. find / -name game Looks for a file named "game" starting at the root directory (searching all directories including mounted filesystems). The `-name' option makes the search case sensitive. You can use the `-iname' option to find something regardless of case. Bash Guide for Beginners.

Examples using grep. 4.2.1. What is grep? Grep searches the input files for lines containing a match to a given pattern list. When it finds a match in a line, it copies the line to standard output (by default), or whatever other sort of output you have requested with options. Though grep expects to do the matching on text, it has no limits on input line length other than available memory, and it can match arbitrary characters within a line. 15 Practical Grep Command Examples In Linux / UNIX. UNIX Commands Quick List. UNIX Environment. Csh One-Liners. This is a collection of useful one-line csh-commands and short multi-line contructs, intended to give some practical hints to both novice and veteran csh and sh users. Copy Linux Files and Copy Directory Using cp Command - Linux Basic Command.

The Linux cp command usually use to copy file and copy directory in Linux operating system. The cp command also can be use to make an link to other file in the system. The execution of cp command and all of the example below tested using bash shell on Linux Fedora Core operating system. Unix: Some Essential Commands. ============================ Some Essential Unix Commands ============================ Like DOS, Unix organizes information by putting *files* in *directories*. Unix Commands. This document provides examples of the use of many of the most common Unix commands. The first thing to remember about Unix commands is that are case sensitive. UNIX 101: Basic UNIX. The Guide - Table of Contents. More UNIX Commands. I have noticed that the overwhelming majority of visitors come to this page via a Lycos search. This page is probably *not* what you're looking for - see the links at the bottom of this page for more useful information!

Jobs --- lists your currently active jobs (those that you put in the background) and their job numbers. Useful to determine which one you want to foreground if you have lots of them. bg --- background a job after suspending it. fg %jobnumber --- foreground a job !! --- repeat the previous command (but CTRL-p, is safer, because you have hit return in addition) ! Pattern --- repeat the last command that starts with patternecho $VARIABLE --- shows the value of an environment variable setenv --- lets you set environment variables. These things are the same as in emacs: UNIX and Linux keyboard shortcuts.

Quick links.