[TUHS] Origin year of BSD csh?
schily at schily.net
Mon Jun 27 20:31:04 AEST 2016
Clem Cole <clemc at ccc.com> wrote:
> A few years later, I did switch to typing to the csh when I got to UCB, but
> that was not until after the MIT job control stuff had been spliced into
> the BSD kernel (Horton & Kleckner were probably the ones that convinced me
> to learn it). With job control I became a fan, but never warmed up to the
> programming syntax. I picked up the mantra that I still consider wise --
> "type to Joy and program to Bourne." This is comfortable for the ROMS in
> the muscles of my fingers, but my scripts are portable.
Job control of course was an important improvement. I took the idea and
implemented in my bsh in 1985.
Now looking back, it is interesting, that there are just four shells that
implement support for vfork():
- csh - the first
- bsh since 1985
- ksh vfork() probably since 1984, jobcontrol apparently since 1982.
- bosh (my recent Bourne Shell) since 2014
But on a decent OS, vfork() helps a lot to speed up the shell.
On Solaris, fork() is copy-on-write based but still 3x slower than vfork().
EMail:joerg at schily.net (home) Jörg Schilling D-13353 Berlin
joerg.schilling at fokus.fraunhofer.de (work) Blog: http://schily.blogspot.com/
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