<aside> 💡 Using regex in man pages

• Type /regexPattern after entering the man page to search for the pattern
• Type n to go to next occurrence
• Type N to go to previous occurrence </aside>

sed

It is a programming language for processing text streams

Introduction

• It is a programming language
• sed is an abbreviation of stream editor
• It is a part of POSIX
• sed precedes awk

Execution Model of sed

• Input stream is a set of lines

• Each line is a sequence of characters

• Two data buffers are maintained → active pattern space and auxiliary hold space

  • Pattern space
    • This is where input lines are loaded for pattern matching and executing actions.
  • Auxiliary hold space
    • Is an extra buffer for storing pattern space content for later use.
    • It provides temporary storage for data from previous lines.

• For each line of input, an execution cycle is performed loading the line into the pattern space

• During each cycle it executes statements in a script for each line of input, based on matching address patterns specified with options.