SED is a stream oriented version of ED
.
The problem is, sed doesn't work like ed for editing files, which results in
$ sed -e 'expr' infile > outfile instead of simply editing the file in place, and the only time you can rely on sed being able to edit a file in place is when it is GNU SED or a specific operating system that supports a comparable feature.
Which means for portability reasons, if you're editing in place, ed and perl are your winners.
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My
Journal
Thou shalt check the array bounds of all strings (indeed, all arrays), for surely where thou typest ``foo'' someone someday shall type ``supercalifragilisticexpialidocious''.