flavours of shell - what is there?

[Byron Rakitzis]

In article <43508 at sequent.UUCP> calvin at crg1.sequent.com (Calvin Goodrich) writes:
>In article <4278 at ecs.soton.ac.uk> tjc at ecs.soton.ac.uk (Tim Chown) writes:
>>
>>The ones I know of are simply:
>>	sh	 csh	 bash	 ksh
>>
>>Are there others?  Where are they principally available from?
>
>here's a little known shell ...
>
>nsh:
>
>	NutSHell, the smallest UnixTM shell yet. Version 1.0 (the only
>one released so far) includes only 'cd' and 'echo <string constant>'.
>GNU-nsh, to be released later this year, is expected to be much more
>powerful, with built-in Bourne, Korn and C shell emulators. The executable
>is expected to go from 306 bytes to 7Mb with this release, however.
>
>(all this comes with a huge :]. i mean really this is one of the few groups
> i've seen that hasn't had any injected humor. ripped off without permission
> from rec.humor.)
>
>calvin.


At the risk of seeming like a braggart, please let me include the
source code to "bsh", the "bull-shell". It is even smaller than the
nsh, since it has only cd as a builtin.  It performs io-redirection and
pipes, however. You may have seen this shell in the 1990 Obfuscated C
comptetition.

		bsh.c (by Byron Rakitzis and Sean Dorward)
--------------------------------CUT HERE----------------------------
# to unbundle, sh this file
# bundled by byron on archone at Thu Oct  4 13:57:32 CDT 1990
# contents of bundle:
#	bsh.c
echo bsh.c
sed 's/^-//' > foo.c <<'end of bsh.c'
-#define D ,close(
-
-char              *c,q              [512              ],m[              256
-],*v[           99], **u,        *i[3 ];f[         2],p; main        (){for
- (m[m        [60]=   m[62      ]=32   ]=m[*      m=124   [m]=       9]=6;
-  e(-8)     ,gets      (1+(    c=q)     )||      exit      (0);     r(0,0)
-   )for(    ;*++        c;);  }r(t,      o){    *i=i        [2]=    0;for
-     (u=v  +98           ;m[*--c]         ^9;m [*c]          &32  ?i[*c
-       &2]=                *u,u-             v^98              &&++u:
-
-	3	)if(!m[*c]){for(*++c=0;!m[*--c];);
-	*	--u= ++c;}u-v^98?strcmp(*u,"cd")?*c?pipe(f),o=f[
-	1	]:
-	4	,(p=fork())?e(p),o?r(o,0)D o)D*f):
-	1	,wait(0):(o?dup2(*f,0)D*f)D o):*i?
-	5	D 0),e(open(*i,0)):
-	9	,t?dup2(t,1)D t):i[
-	2	]?
-	6	D 1),e(creat(i[2],438)):
-	5	,e(execvp(*u,u))):e(chdir(u[1])*2):
-	3	;}e(x){x<0?write(2,"?\n$ "-x/4,2),x+1||exit(1):
-	5	;}
end of bsh.c