Campesato Oswald / Кампесато Освальд - Working with Grep, Sed, and Awk Pocket Primer / Работа с Grep, Sed и Awk [2023, PDF, EPUB, ENG]

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Preface
Chapter 1 Working with grep
What is the grep Command?
Meta Characters and the grep Command
Escaping Meta Characters with the grep Command
Useful Options for the grep Command
Character Classes and the grep Command
Working with the –c Option in grep
Matching a Range of Lines
Using Backreferences in the grep Command
Finding Empty Lines in Datasets
Using Keys to Search Datasets
The Backslash Character and the grep Command
Multiple Matches in the grep Command
The grep Command and the xargs Command
Searching Zip Files for a String
Checking for a Unique Key Value
Redirecting Error Messages
The egrep Command and fgrep Command
Displaying “Pure” Words in a Dataset with egrep
The fgrep Command
Delete Rows with Missing Values
A Simple Use Case
Summary
Chapter 2 Working with sed
What is the sed Command?
The sed Execution Cycle
Matching String Patterns Using sed
Substituting String Patterns Using sed
Replacing Vowels from a String or a File
Deleting Multiple Digits and Letters from a String
Search and Replace with sed
Regular Expressions with sed
Datasets with Multiple Delimiters
Useful Switches in sed
Working with Datasets
Printing Lines
Character Classes and sed
Removing Control Characters
Counting Words in a Dataset
Back References in sed
One-Line sed Commands
Populate Missing Values with the sed Command
A Dataset with 1,000,000 Rows
Numeric Comparisons
Counting Adjacent Digits
Average Support Rate
Summary
Chapter 3 Working with awk
The awk Command
Launching awk Commands and File Extensions
Built-In Variables that Control awk
How Does the awk Command Work?
Three Important Code Blocks in awk Commands
Different Ways to Print Text
Working with the -F Switch in awk
Splitting Strings into Characters
The PROCINFO Array
Ignore Case in awk
Working with OFS, ORS, and Linefeed versus “\n”
Linefeed versus “\n”
Basic awk Examples with Text Files
Display the Contents of a File
Omit the Header Line of a File
Display a Range of Lines in a Text File With NR
Display a Range of Lines Based on Strings
Insert Blank Lines
Remove Blank Lines
Specifying the Number of Fields
Changing the Field Separator FS
Exclude Fields
Switch Adjacent Fields
Display Fields in Reverse Order
Count Non-Empty and Empty Rows
Detecting Transfer Protocols
Detecting Number Formats
Working with Record Lengths
Aligning Text with the printf() Statement
Working with Loops in awk
A for Loop in awk
Exponents in a for Loop
A for Loop with a break Statement
Working with while Loops in awk
A do-while Loop in awk
Conditional Logic and Control Statements
The break, continue, and next Keywords in awk
The exit Keyword
Conditionally Displaying Fields
Logical Operators in awk
Logical Operators and Partial Matches
Checking for Leap Years
Formatting Output
Floating Point Output
Inserting a Thousands Separator
Scientific Notation
Rounding and Truncating Numbers
Rounding Numbers
Truncating Numbers
Numeric Functions in awk
Convert Base 10 to Binary
Built-In String Functions in awk
Convert Strings to Lowercase in awk
Convert Strings to Uppercase in awk
Convert Strings to Mixed Case in awk
Counting Lines that Match a Character
Working with the match() Function
Characters and Hexadecimal Numbers in awk
Non-Printable Characters
Hexadecimal Numbers
Summary
Chapter 4 Working with awk, Part 2
Working with Arrays in awk
Initializing and Printing the Contents of an Array
Initializing and Deleting the Contents of an Array
Adding an Array of Numbers
Find the Maximum and Minimum of an Array of Numbers
Concatenating an Array of Strings
Generating Arrays from Input Strings
The split() Function with Linefeed Strings
Using the split() Function with the case Statement
The patsplit() Function
Multi-Dimensional Arrays
Higher Dimensionality Arrays
Calculating Invoice Totals (1)
Calculating Invoice Totals (2)
Calculating Invoice Averages
Counting Fields in Text Files
Displaying the Number of Fields in Text Files
Deleting Alternate Lines in Datasets
Print a Range of Strings in Datasets
Print a Range of Dates in Datasets
Merging Lines in Datasets
Printing File Contents as a Single Line
Joining Groups of Lines in a Text File
Joining Alternate Lines in a Text File
Reversing the Lines in a File
Working with Duplicate Lines in a File
Display Duplicate Rows
Remove Duplicate Rows
Uniformity of Data Values
Count Duplicate Fields in a File
Calculating Invoice Totals
Printing Lines Using Conditional Logic
Duplicate and Unique Rows in Text Files
Splitting Filenames with awk
One-Line awk Commands
Useful Short awk Scripts
Printing the Words in a Text String in awk
Count Occurrences of a String in Specific Rows
Well-Known Sorting Algorithms
The Bubble Sort
Find Anagrams in a List of Words
Sort an Array in O(n) Complexity
Find the Median of an Array of Numbers
Linear Search
Binary Search (Iterative)
Binary Search Walkthrough
Code for a Binary Search (Iterative)
Binary Search (Recursive)
Summary
Chapter 5 Working with awk, Part 3
Bit Operations in awk
Logical AND
Logical OR
Logical XOR
Logical NOT
Logical Left Shift
Logical Right Shift
Reverse a String
Find Palindromes
Check for Unique Characters
Check for Balanced Parentheses
Printing a String in a Fixed Number of Columns
Printing a Dataset in a Fixed Number of Columns
Aligning Columns in Datasets
Aligning Columns and Multiple Rows in Datasets
Displaying a Subset of Columns in a Text File
Subsets of Columns Aligned Rows in Datasets
Longest/Shortest Words in Datasets
Counting Word Frequency in Datasets
Displaying Only “Pure” Words in a Dataset
Delete Rows with Missing Values
Working with Multiline Records in awk
CSV Files with Multirow Records
Processing Multiple Files with awk
Inner Join of Two Files in awk
Logical Operators in awk
A Simple Use Case
Another Use Case
Date Conversion
A Dataset with 1,000,000 Rows
Numeric Comparisons
Counting Adjacent Digits
Average Support Rate
What is Recursion?
Arithmetic Series
Calculating Arithmetic Series (Iterative)
Calculating Arithmetic Series (Recursive)
Calculating Partial Arithmetic Series
Geometric Series
Calculating a Geometric Series (Iterative)
Calculating Arithmetic Series (Recursive)
Factorial Values
Fibonacci Numbers
Euclid’s Algorithm (GCD)
Lowest Common Multiple of Two Positive Integers
Composite versus Prime Numbers
Factors of Positive Integers
Goldbach’s Conjecture
Environment Variables in awk
Summary
Chapter 6 Regular Expressions
What are Regular Expressions?
Metacharacters
Character Sets
Working with “^” and “\”
Character Classes
POSIX Character Classes
Generic Character Classes
Regular Expressions in awk
Matching Strings with the Dot “.” Metacharacter
Matching Strings with the “^” Metacharacter
Matching Strings with the “$” Metacharacter
Matching Strings with the “|” Metacharacter
Matching with ?, +, or * Metacharacters
Matching Subgroups with ?, +, or * Metacharacters
Matching with Character Classes
Working with Postfix Arithmetic Operators
Working with the sub() Function in awk
Examples Using the sub() Function
Working with the gsub() Function
Removing Digits with the gsub() Function
Removing Characters with the gsub() Function
Removing Consecutive Characters with the gsub() Function
Removing Complements of Strings with the gsub() Function
Removing Metacharacters with the gsub() Function
Removing Spaces in Text Fields
Splitting Strings with Regular Expressions
Dynamic Regular Expressions
Regular Expressions Involving Text Files
Counting Comments with Regular Expressions
Combining grep with awk
Combining sed with awk
Removing HTML Tags
The gensub() Function and Captured Groups
Summary
Index