sed is suitable for stream editing, such as replacing, deleting or inserting text; awk is suitable for data extraction and reporting, can process structured data and perform logical operations. Specifically: 1. Sed process row by row, good at simple replacement and row operations; 2. Awk processed by fields, supporting complex logic such as variables and conditions; 3. Use sed for quick editing, use awk to analyze data or generate reports. The two are often used in combination to give full play to their respective advantages.

If you're working with text processing in the Linux or Unix environment, you might have come across both sed and awk . They're powerful tools often used together in shell scripts or command-line pipelines. But they serve different purposes and have distinct strengths. Here's a straightforward breakdown of how they different.

What sed is best for: Stream editing

sed , short for "stream editor," is mainly used for parsing and transforming text line by line. It's great when you want to do things like:

• Replace certain text patterns
• Delete lines matching a pattern
• Insert or append content

For example, if you want to replace every occurrence of "apple" with "orange" in a file, sed can do that quickly:

 sed 's/apple/orange/g' filename.txt

It works well on streams — meaning it can process input as it comes, without needing to load the whole file into memory. That makes sed fast and efficient for simple edits across large files or data streams.

Where awk shines: Data extraction and reporting

awk is more like a full-fledged programming language designed for pattern scanning and processing. It's ideal when you need to:

• Work with structured data (like CSV or log files)
• Do calculations or conditional logic
• Extract specific fields or columns

Unlike sed , which treats each line as a whole, awk splits each line into fields automatically. This makes it easier to work with tabular data.

Say you have a file with names and scores:

 John 85
Jane 92
Mark 78

You could use awk to print only those who scored over 90:

 awk '$2 > 90' filename.txt

This would output:

 Jane 92

That kind of field-based logic is harder to pull off cleanly in sed .

Key differences in approach

Here are some core distinctions that define when to choose one over the other:

• Processing model :

  • sed works on lines at a time.
  • awk works on fields within lines.

• Complexity :

  • sed is simpler and better for basic find-and-replace or line manipulations.
  • awk supports variables, conditions, loops, and functions — so it can handle more complex logic.

• Use cases :

  • Use sed for quick substitutions, deletions, or small edits.
  • Use awk when dealing with structured data, performing calculations, or generating reports.

They also complement each other — sometimes you'll see them chained together in a pipeline to get the best of both worlds.

So, basically:
If your task is about editing lines of text, sed is likely your go-to. If you're analyzing or summarizing data broken into columns or fields, awk fits better. They're both worth learning, and knowing when to reach for each make text processing much smoother.

The above is the detailed content of What is the difference between sed and awk?. For more information, please follow other related articles on the PHP Chinese website!