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diff --git a/ult/ult_7/script2col.rst b/ult/ult_7/script2col.rst deleted file mode 100644 index b15e85c..0000000 --- a/ult/ult_7/script2col.rst +++ /dev/null @@ -1,210 +0,0 @@ -.. Objectives -.. ---------- - - .. At the end of this tutorial, you will be able to: - - .. 1. Sort lines of text files - .. 2. Print lines matching a pattern - .. 3. Translate or delete characters - .. 4. Omit repeated lines - - -.. Prerequisites -.. ------------- - -.. 1. Getting started with Linux -.. 2. Redirection and Piping - - - -Script ------- - - - -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Show the first slide containing title, name of the production | Hello friends and Welcome to the tutorial on 'Text Processing'. | -| team along with the logo of MHRD }}} | | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Show slide with objectives }}} | At the end of this tutorial, you will be able to, | -| | | -| | 1. Sort lines of text files | -| | #. Print lines matching a pattern | -| | #. Translate or delete characters | -| | #. Omit repeated lines. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Switch to the pre-requisite slide }}} | Before beginning this tutorial,we would suggest you to complete the | -| | former tutorials as being displayed currently. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Open the terminal }}} | In this tutorial, we shall learn about text processing. | -| :: | TO begin with, consider data kept in two files, namely marks1.txt and | -| | students.txt | -| cat marks1.txt | Let us see what data they contain. Open a terminal and type, | -| cat students.txt | | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | Let's say we wish to sort the output in the alphabetical order | -| | of the names of the files. We can use the ``sort`` command for this | -| cut -d " " -f 2- marks1.txt | paste -d " " students.txt -| sort | purpose. | -| | | -| | We just pipe the previous output to the ``sort`` command as, | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | Let's say we wish to sort the names, based on the marks in the first | -| | subject i.e. the first column after the name. ``sort`` command also allows us to | -| cut -d " " -f 2- marks1.txt | paste -d " " students.txt -| sort -t " " -k 2 | specify the delimiter between the fields and sort the data on a particular | -| | field. ``-t`` option is used to specify the delimiter and ``-k`` option | -| | is used to specify the field. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Show slide with, Sort... }}} | This command give us a sorted output as required. But, what if we would | -| | like the output to appear in the reverse order. ``-r`` option allows the output | -| | to be sorted in the reverse order and the ``-n`` option is used to choose | -| | a numerical sorting. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Switch to the terminal }}} | Let us do it on the terminal and see for ourselves, | -| :: | | -| | | -| cut -d " " -f 2- marks1.txt | paste -d " " students.txt -| | | -| sort -t " " -k 2 -rn | | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | Suppose, While you are compiling the student marklist, Anne walks up to you and | -| | wants to know her marks. You, being a kind person that you are, oblige. | -| cut -d " " -f 2- marks1.txt | paste -d " " students.txt - | grep Anne | But you do not wish to her to see the marks that others have scored. What | -| | do you do? Here, the ``grep`` command comes to your rescue. | -| | | -| | ``grep`` is a command line text search utility. You can use it to search | -| | for Anne and show her, what she scored. ``grep`` allows us to search for a | -| | search string in files. But we could, like any other command, pipe the | -| | output of other commands to it. So, we shall use the previous combination | -| | of cut and paste that we had, to get the marks of students along with their | -| | names and search for Anne in that. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | This will give us only the line containing the word Anne as the output. | -| | The grep command is by default case-sensitive. So, we wouldn't have got | -| cut -d " " -f 2- marks1.txt | paste -d " " students.txt - | grep -i Anne | the result if we had searched for anne, with a small a, instead of | -| | Anne, with a capital a. But, what if we didn't know, whether the name was | -| | capitalized or not? ``grep`` allows you to do case-insensitive searches | -| | by using the ``-i`` option. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | Now, in another scenario, if we wished to print all the lines, which do | -| | not contain the word Anne, we could use the ``-v`` option. | -| cut -d " " -f 2- marks1.txt | paste -d " " students.txt - | grep -iv Anne | | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Switch to the terminal }}} | grep allows us to do more complex searches, for instance, searching for | -| :: | sentences starting or ending with a particular pattern and regular | -| | expression based searches. | -| cat students.txt | tr a-z A-Z | | -| | {{{ Show slide with, tr }}} | -| | | -| | ``tr`` is a command that takes two sets of characters as parameters, and | -| | replaces occurrences of the characters in the first set with the | -| | corresponding elements from the other set. It reads from the standard | -| | output and writes to the standard output. | -| | | -| | For instance, if we wish to replace all the lower case letters in the | -| | students file with upper case, we can do it as, | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | A common task is to remove empty newlines from a file. The ``-s`` flag | -| | causes ``tr`` to compress sequences of identical adjacent characters in its | -| tr -s '\n' '\n' | output to a single token. For example, | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | Hit enter 2-3 times and see that every time we hit enter we get a newline. | -| | | -| <Enter> | | -| <Enter> | | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | It replaces sequences of one or more newline characters with a single newline. | -| | | -| cat foo.txt | tr -d '\r' > bar.txt | The ``-d`` flag causes ``tr`` to delete all tokens of the specified set of | -| | characters from its input. In this case, only a single character set | -| | argument is used. The following command removes carriage return characters, | -| | thereby converting a file in DOS/Windows format to the Unix format. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | The ``-c`` flag complements the first set of characters. | -| | | -| tr -cd '[:alnum:]' | | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | It therefore removes all non-alphanumeric characters. | -| | | -| cat items.txt | Let us consider one more scenario.Suppose we have a list of items, say books, | -| | and we wish to obtain a list which names of all the books only once, without | -| | any duplicates. To achieve this, we use the ``uniq`` command. Let us first | -| | have a look at our file | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | Now, let us try and get rid of the duplicate lines from this file using | -| | the ``uniq`` command. | -| uniq items.txt | | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | Nothing happens! Why? The ``uniq`` command removes duplicate lines only when | -| | they are next to each other. So, henceforth, we get a sorted file from the | -| sort items.txt | uniq | original file and work with that file. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | ``uniq -u`` command gives the lines which are unique and do not have any | -| | duplicates in the file. ``uniq -d`` outputs only those lines which | -| uniq -u items-sorted.txt | have duplicates. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| :: | The ``-c`` option displays the number of times each line occurs in the file. | -| | | -| uniq -dc items-sorted.txt | | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Show summary slide }}} | This brings us to the end of the end of this tutorial. | -| | In this tutorial, we have learnt to, | -| | | -| | 1. Use the ``sort`` command to sort lines of text files. | -| | #. Use the ``grep`` command to search text pattern. | -| | #. Use the ``tr`` command to translate and/or delete characters. | -| | #. Use the ``uniq`` command to omit repeated lines in a text. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Show self assessment questions slide }}} | Here are some self assessment questions for you to solve | -| | | -| | 1. To obtain patterns; one per line, which of the following command is used ? | -| | | -| | - grep -f | -| | - grep -i | -| | - grep -v | -| | - grep -e | -| | | -| | 2. Translate the word 'linux' to upper-case. | -| | | -| | 3. Sort the output of the ``ls -al`` command. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Solution of self assessment questions on slide }}} | And the answers, | -| | | -| | 1. In order to obtain patterns one per line, we use the ``grep`` command | -| | alongwith the -f option. | -| | | -| | 2. We use the tr command to change the word into uppercase | -| | :: | -| | | -| | echo 'linux' | tr a-z A-Z | -| | | -| | | -| | 3. We use the sort command as, | -| | :: | -| | | -| | ls -al | sort -n -k5 | -| | The -n means "sort numerically", and the -k5 option means to key off of | -| | column five. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Show the SDES & FOSSEE slide }}} | Software Development techniques for Engineers and Scientists - SDES, is an | -| | initiative by FOSSEE. For more information, please visit the given link. | -| | | -| | Free and Open-source Software for Science and Engineering Education - FOSSEE, is | -| | based at IIT Bombay which is funded by MHRD as part of National Mission on | -| | Education through ICT. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Show the ``About the Spoken Tutorial Project'' slide }}} | Watch the video available at the following link. It summarises the Spoken | -| | Tutorial project.If you do not have good bandwidth, you can download and | -| | watch it. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Show the `` Spoken Tutorial Workshops'' slide }}} | The Spoken Tutorial Project Team conducts workshops using spoken tutorials, | -| | gives certificates to those who pass an online test. | -| | | -| | For more details, contact contact@spoken-tutorial.org | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Show the ``Acknowledgements'' slide }}} | Spoken Tutorial Project is a part of the "Talk to a Teacher" project. | -| | It is supported by the National Mission on Education through ICT, MHRD, | -| | Government of India. More information on this mission is available at the | -| | given link. | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ -| {{{ Show the Thank you slide }}} | Hope you have enjoyed this tutorial and found it useful. | -| | Thank you! | -+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+ |