sed & awk, 2nd Edition

Append, Insert, and Change

The append (a), insert (i), and change (c) commands provide editing functions that are commonly performed with an interactive editor, such as vi. You may find it strange to use these same commands to “enter” text using a noninteractive editor. The syntax of these commands is unusual for sed because they must be specified over multiple lines. The syntax follows:

append	[line-address]a\
	text
insert	[line-address]i\
	text
change	[address]c\
	text

The insert command places the supplied text before the current line in the pattern space. The append command places it after the current line. The change command replaces the contents of the pattern space with the supplied text.

Each of these commands requires a backslash following it to escape the first end-of-line. The text must begin on the next line. To input multiple lines of text, each successive line must end with a backslash, with the exception of the very last line. For example, the following insert command inserts two lines of text at a line matching “<Larry’s Address>”:

/<Larry's Address>/i\
4700 Cross Court\
French Lick, IN

Also, if the text contains a literal backslash, add an extra backslash to escape it.^[5]

The append and insert commands can be applied only to a single line address, not a range of lines. The change command, however, can address a range of lines. In this case, it replaces all addressed lines with a single copy of the text. In other words, it deletes each line in the range but the supplied ...