in vim, how to capitalise every word?

To capitalize the first letter of every word in a line or selection in Vim, you can utilize a combination of commands.

For a single line:

• Place the cursor at the beginning of the line.
• Enter the following command in normal mode:

Code

    :s/\<\(\w\)\(\w*\)\>/\U\1\L\2/g

• : enters command-line mode.
• s/ initiates a substitute command.
• \<\(\w\)\(\w*\)\> matches a whole word:
  • \< matches the beginning of a word.
  • \(\w\) captures the first word character into group 1.
  • \(\w*\) captures the remaining word characters into group 2.
  • \> matches the end of a word.
• \U\1\L\2 replaces the matched word:
  • \U\1 converts the first captured character (group 1) to uppercase.
  • \L\2 converts the remaining captured characters (group 2) to lowercase.
• /g ensures all occurrences on the line are processed.

For a visual selection (multiple lines or a block):

• Enter visual mode (e.g., by pressing v, V, or Ctrl-v).
• Select the desired text.
• Enter the following command:

Code

    :'<,'>s/\<\(\w\)\(\w*\)\>/\U\1\L\2/g

• '<,'> automatically populates the range for the visual selection.
• The rest of the command is identical to the single-line substitution.

For the entire file:

• Enter the following command in normal mode:

Code

    :%s/\<\(\w\)\(\w*\)\>/\U\1\L\2/g

• % specifies the entire file as the range for the substitution.
• The rest of the command is identical to the single-line substitution.