The RFile and WFile variables must end the command line and must be preceded by exactly one blank. Each WFile variable is created before processing begins. The sed command can process up to 999 subcommands in a pattern file. Text Places the Text variable in output before reading the next input line. If the label variable is empty, it branches to the end of the script.
Text Deletes the pattern space.
With 0 or 1 address or at the end of a 2-address range, places the Text variable in output and then starts the next cycle. D Deletes the initial segment of the pattern space through the first new-line character and then starts the next cycle. Replaces the contents of the hold space with the contents of the pattern space. H Appends the contents of the pattern space to the hold space. Text Writes the Text variable to standard output before reading the next line into the pattern space.