A sed program consists of one or more sed commands, passed in by one or more of the -e, -f, --expression, and --file options, or the first non-option argument if zero of these options are used. This document will refer to “the” sed script; this is understood to mean the in-order catenation of all of the scripts and script-files passed in.
Commands within a script or script-file can be
separated by semicolons (
;) or newlines (ASCII 10).
Some commands, due to their syntax, cannot be followed by semicolons
working as command separators and thus should be terminated
with newlines or be placed at the end of a script or script-file.
Commands can also be preceded with optional non-significant
sed command consists of an optional address or
address range, followed by a one-character command name
and any additional command-specific code.