a regex extracting and template replacement, though arbitrarily complicated transforms are in principle possible by using the hold buffer. Conversely, for simpler operations, specialized Unix utilities such as grep (print lines matching a pattern), head (print the first part of a file), tail (print the last part of a file), and tr (translate or delete characters) are often preferable. For the specific tasks they are designed to carry out, such specialized utilities are usually simpler, clearer, and faster than a more general solution such as sed. The ed/sed commands and syntax continue to be used in descendent programs, such as the text editors vi and vim. An analog to ed/sed is sam/ssam, where sam is the Plan 9 editor, and ssam is a stream interface to it, yielding functionality similar to sed. See also List of Unix commands Turing tarpit Notes References Further reading Bell Lab's Eighth Edition (circa 1985) Unix sed(1) manual page GNU sed documentation or the manual page Sourceforge.net, the sed FAQ (March, 2003) External links Sed - An Introduction and Tutorial, by Bruce Barnett (includes manual) Cross-platform software Pattern matching programming languages Scripting languages Standard Unix programs Text-oriented programming languages Unix text processing utilities Unix SUS2008 utilities Plan 9 commands IBM i Qshell commands Console applications Programming languages created in 1974