Linux in a Nutshell, 6th Edition

Examples of Searching and Replacing

The examples in the following table show the metacharacters available to sed or ex. Note that ex commands begin with a colon. A space is marked by a ❐; a tab is marked by a tab.

Command	Result
s/.*/( & )/	Redo the entire line, but add spaces and parentheses.
s/.*/mv & &.old/	Change a wordlist (one word per line) into mv commands.
/^$/d	Delete blank lines.
:g/^$/d	Same as previous, in ex editor.
/^[❐tab]*$/d	Delete blank lines, plus lines containing only spaces or tabs.
:g/^[❐tab]*$/d	Same as previous, in ex editor.
s/❐❐*/❐/g	Turn one or more spaces into one space.
:%s/❐❐*/❐/g	Same as previous, in ex editor.
:s/[0-9]/Item &:/	Turn a number into an item label (on the current line).
:s	Repeat the substitution on the first occurrence.
:&	Same as previous.
:sg	Same as previous, but for all occurrences on the line.
:&g	Same as previous.
:%&g	Repeat the substitution globally (i.e., on all lines).
:.,$s/Fortran/\U&/g	On current line to last line, change word to uppercase.
:.,$s/\(F\)\(ORTRAN\)/\1\L\2/g	On current line to last line, change spelling of “FORTRAN” to correct, modern usage.
:%s/.*/\L&/	Lowercase entire file.
:s/\<./\u&/g	Uppercase first letter of each word on current line. (Useful for titles.)
:%s/yes/No/g	Globally change a word to No.
:%s/Yes/˜/g	Globally change a different word to No (previous replacement).

Finally, some sed examples for transposing words. A simple transposition of two words might look like this:

s/die or do/do or die/                 Transpose words

The real trick is to use hold ...