25.9 Adding and Deleting White Space

There are a lot of ways to change the amount of white space (space and tab characters) in a line:

• Berkeley systems have cat -s ( 25.10 ) to replace sets of two or more blank lines with single blank lines. If you don't have cat -s or need something different, look at article 34.18 .

• The crush ( 25.11 ) script removes all blank lines.

• Use doublespace and triplespace ( 25.12 ) to double- and triple-space text.

• The pushin ( 25.13 ) script replaces multiple white space characters with a single space. This can shorten long lines.

• You can use sed to indent lines of text before printing ( 43.9 ) . The offset ( 35.7 ) shell script does that more easily.

• For other jobs, utilities like awk ( 33.11 ) and sed ( 34.24 ) will probably do what you want. You have to understand how to program them before you use them.