----------------------------- Table 4.2 -----------------------------
            Summary of sed Commands

a\              append lines to output until one not ending in \
b label         branch to command : label
c\              change lines to following text as in a
d               delete line; read next input line
i\              insert following text before next output
l               list line, making all non-printing characters visible
p               print line
q               quit
r file          read file, copy contents to output
s/old/new/f     substitute new for old. If f=g, replace all occurrences;
                    f=p, print; f=w file, write to file
t label         test: branch to label if substitution made to current line
w file          write line to file
y/str1/str2     replace each character from str1 with corresponding
                    character from str2 (no ranges allowed)
=               print current input line number
!cmd            do sed cmd only if line is not selected
: label         set label for b and t Commands
{               treat commands up to matching } as a group
