To delete everything in a file with Vim, use this command.

ggdG

explain

• gg go to the first line
• dG delete to the last line of file (G is movement which is " go to the last line of the document ")

You can also apply this grammar by replacing d with something else. For example

• gg=G auto format file
• gggUG make all text in file upper case.
• ggVG select all text in file