16-Apr-2025

Vim Substitution

Substituting text within Vim is a powerful editing feature, allowing for complex replacements and manipulations. This goes beyond simple find-and-replace functionality, offering pattern matching and special characters for fine-grained control.

The basic substitution command in Vim follows this structure:

:s/{pattern}/{replacement}/{flags}

Let’s break down each component:

:: Enters command mode.
s: Indicates the substitution command.
{pattern}: The text you want to search for. This can be a literal string or a regular expression.
{replacement}: The text you want to replace the pattern with. This can also include special characters.
{flags}: Optional flags that modify the substitution’s behavior.

Examples:

Simple Replacement: Replace “apple” with “orange” on the current line:

   :s/apple/orange

Global Replacement: Replace all occurrences of “apple” with “orange” in the entire file:
```
:%s/apple/orange/g
```

Here, % represents all lines, and g stands for global.

Case-Insensitive Replacement: Replace “apple” with “orange”, ignoring case:
```
:s/apple/orange/i
```
Confirming Replacements: Replace “apple” with “orange”, but ask for confirmation before each replacement:

   :%s/apple/orange/gc

The c flag prompts for confirmation.

Using Regular Expressions: Replace all occurrences of a digit followed by the letter “a” with “X”:

   :%s/\d\+a/X/g

Here, \d\+ represents one or more digits.

Using Capture Groups: Swap the order of two words separated by a space:

   :s/\(\w\+\) \(\w\+\)/\2 \1/

The \(...\) define capture groups, and \1 and \2 refer to the captured text.

Special Characters in Replacement: Replace “apple” with “apple (replaced)”:


    :s/apple/apple (&)/

`&` represents the entire matched pattern.  You can also use `\0`.  Similarly, `\1`, `\2`, etc., refer to captured groups if regular expressions are used.

Beyond the Basics:

The substitution command offers much more. Experiment with different regular expressions and flags to harness its full potential. The :help :s command within Vim provides comprehensive documentation on all the options available. Mastering substitution will significantly enhance your text editing efficiency in Vim.