5.6.1. sed addresses

To limit the extent of an command, we have to use addresses. A command can accept zero, one or two addresses. An address can be a regular expression or a line-number.

• if no address is specified, the command is executed for each line

• if one address is specified, the command is applied for each line matching the address

• if two addresses are specified, the command is performed to the first line and all following lines up to and including the second match

• if an addres is followed by a !, the command is used on all lines that do not match the address

Some examples (using the d command, which delets the matching line(s):

• $d deletes the last line of the input ($ means the last line)

• 11,$d deletes all lines from line 11 (so keeping the first 10 lines)

• /^$/d deletes all blank lines; a regexp is enclosed in /