[TUHS] Bell Labs sed performance

[Douglas McIlroy via TUHS]

DIomidis's note is a welcome tribute to its creator, Lee McMahon,
perhaps the least well known member of the original Unix cohort. He
reported to the Visual and Acoustics Research Center, not CSRC. A
linguist and former Jesuit seminarian, Lee brought a strong
liberal-arts perspective to the team and played a central role in the
first Unix text-analysis project, statistical study of the Federalist
papers in the tradition of Frederick Mosteller. The project exploited
the nascent software toolkit. At least one Unix staple came out of the
project, Lee's comm(1).

Sed, Lee's biggest software-tool contribution, made its debut in v7.
Calling attention to it, the introduction to the v7 manual  said, "It
is well worth learning". Although sed has been widely upstaged by awk,
it stands as a beacon of power and simplicity.. Both had 3-page
entries in the manual, but awk requires one to know C, while sed's
only prerequisite is ed.

Outside of Unix, Lee, Ken, Joe Condon and others made TPC (The Phone
Company), a demonstration telephone switch, which ran many phones in
1127 for several years, and, more importantly, influenced the
architecture of #5 ESS, AT&T's workhorse switch. Lee conceived TPC's
basic software architecture of one process per device, in contrast to
previous architectures' process-per-call or process-per function.

Doug

On Mon, Mar 23, 2026 at 6:49 AM John P. Linderman via TUHS
<tuhs at tuhs.org> wrote:
>
> Russ Cox has written extensively <https://swtch.com/~rsc/regexp/> about
> regular expression matching, and why some "features", like backtracking,
> may not be a good idea. -- jpl
>
> On Mon, Mar 23, 2026 at 5:05 AM Diomidis Spinellis via TUHS <tuhs at tuhs.org>
> wrote:
>
> > Over the past year I ported the (now {Free,Net,Open})BSD version of
> > sed(1) I implemented in C in the 1990s into Rust as part of the uutils
> > initiative.  I've described the process in a series of four IEEE
> > Software "Adventures in Code" [2] columns.  In this March's column [3] I
> > compare the performance of the Rust implementation against that of GNU,
> > FreeBSD, and the original 1970s Bell Labs Seventh Research Edition one
> > [6].  Amazingly, in four benchmarks the Bell Labs implementation is
> > still the fastest.  At 1850 lines of code (including a regular
> > expression engine) it's also the smallest one (FreeBSD, 2672 LoC; GNU
> > 5462; Rust, 8946).  Admittedly, modern sed versions have more features.
> > Still, one can only admire the design and craftsmanship that went into
> > the original implementation.
> >
> > [1] https://github.com/uutils/sed
> > [2] https://www.spinellis.gr/adventures-in-code.html
> > [3] https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11433192
> > [4] https://github.com/dspinellis/sed-research-v7
> >