You can use an expression as the replacement string in the substitute command (:s). When the replacement string starts with \= it is evaluated as an expression. This opens whole new avenue of interesting possiblities. Here are a few examples:

• Number all the lines in a file (insert line number followed by a tab):

:%s/^/\=line('.')."\t"/

• Number a range of lines (from line 10 to line 20):

:10,20s/^/\=line('.')."\t"/

• Number a range of lines sequentially starting from 1:

:let counter=0|10,20g//let counter=counter+1|s/^/\=counter."\t"

• Number all the paragraphs in range starting from 1 (assuming the paragraphs are separated by one or more blank lines):

:let counter=0|1,20g/^$\n^\s*[^\s]/let counter=counter+1|+1s/^/\=counter."\t"

Note: The above command does not work for the first paragraph in the file if there is no blank line above it.

• Create a file skeleton with dynamic content by using eval() in the expression.

ReferencesEdit

• :help sub-replace-special
• :help sub-replace-expression

CommentsEdit

You can also substitute inside substitute!

:%s#.*#\='cp '.submatch(0).' all/'.substitute(submatch(0),'/','_','g')#

The substitute uses # (not a slash) as the delimiter because / appears in the replacement text. The search pattern (.*) is submatch(0).

The replacement expression inserts "cp " and "all/" and changes any "/" to "_", for example changing line:

sub1/sub2/file1.html

to

cp sub1/sub2/file1.html all/sub1_sub2_file1.html

See Best Vim Tips for a few more.

For incremented columns, see generating a column of increasing numbers: incremented, decremented, daynames, dates, etc.