egrep (grep -E) supports extended metacharacters for regular expressions 1. Use regular rules to determine the need [[ ]] num1=1 [[ $num1 =~ ^[0-9] + $ ]] & amp; & amp; echo “yes” || echo “no” num3=1b1 [[ $num3 =~ ^[0-9] + $ ]] & amp; & amp; echo “yes” || echo “no” 2, * […]
Tag: grep
Regular expressions and grep command
1. Concept: Regular expressions are used to find, replace, and delete one or more lines of text strings through the arrangement of some special characters. In the Shell command line, users can use the grep command to test Parameters Description -b For each line of output, show the byte offset in the file of the […]
shell three musketeers (grep, sed, awk)
Table of Contents 1. Regular expressions 1 Overview 2. Basic metacharacters of regular expressions 3. Regular expression expansion metacharacters 2. grep and egrep 1.Basic example 3.sed (streaming text editor) sed stream editor usage and analysis 4.awk text editor tool awk commonly used built-in variables Example 1. Regular expression 1. Overview Regular Expression (RE) is a […]
Super detailed experiment on Linux text processing tools sed, awk and grep
Article directory 1. sed (good at line fetching and replacement) Brief description Order Command format Common optionsoptions address delimitation Edit commandcommand Advanced editing commands Pattern space and maintaining spatial relationships experiment 2. awk (good at fetching columns) Brief description grammar Order built-in variables Custom variables (character case sensitive) experiment 3. grep (good at searching) Brief […]
Mastering the grep command: A complete guide to an efficient text search tool
Article directory introduction 1.1 What is grep command 1.2 The role and use of grep Basic usage 2.1 Introduction to regular expressions 2.2 Basic syntax of grep 2.3 Search text files 2.4 Search for files in a folder Advanced search options 3.1 Ignore case 3.2 Reverse matching 3.3 Output the number of matching lines 3.4 […]
Linux: text search command grep
Related Reading Linuxhttps://blog.csdn.net/weixin_45791458/category_12234591.html grep is used in Unix-like systems to search and print lines that match a certain pattern in files. The basic syntax of the grep command is as follows: grep [OPTIONS] PATTERN [FILE…] grep [OPTIONS] [-e PATTERN | -f FILE] [FILE…] grep searches named input files, i.e., the last [FILE…] (or standard input […]
The Three Musketeers of Text in Shell Programming-grep
1.grep introduction grep filter general-purpose regular expression analysis program grep,egrep,fgrep Filter by matching grep [options] pattern [files] or grep [-abcEFGhHilLnqrsvVwxy][-A<Number of displayed rows>][-B<Number of displayed columns>][-C<Number of displayed columns>][-d<Perform action>][-e<Template style>][- f<template file>][–help][template style][file or directory…] pattern – represents the string or regular expression to find. files – represents the file name to be searched. […]
Linux regular expressions and grep
What is bash bash is a command processor that runs in a text window and can execute commands entered directly by the user Bash can also read linxu commands from files, called scripts bash supports wildcards, pipes, command substitution, conditional judgment and other logical control statements bash features Command line expansion [root@chaogelinux ~]# echo {tom,bob,chaoge,jerry} […]
Grep and regular expressions
1. Text Processing Three Musketeers grep For Linux enthusiasts of all kinds, if they want to play with Linux, they must understand and master the Three Musketeers of Linux text processing. Today, let’s talk about grep, one of the Three Musketeers. 1. Text Three Musketeers’ Grep 1. What is grep grep stands for Global search […]
How to use grep command in Linux/macOS
Global regular expression printing (grep) is a powerful tool that searches a text file or standard input for lines matching a regular expression and prints the results to standard output. A regular expression (regex) is a special sequence of characters that helps you efficiently match strings in text or files. In UNIX/Linux, the grep command […]