created 2004 · complexity intermediate · author Raj Kiran Grandhi · version 6.0
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.
References
Comments
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.