Date: Thu, 28 Oct 93 19:47:38 PDT
From: Peter Crowley <pcrowley AT qdeck DOT com>
To: turnbull AT shako DOT sk DOT tsukuba DOT ac DOT jp, vic AT THEORY DOT qdeck DOT com
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: popen


Text item: 

>    If you don't really need pipes, but just want to pass input to a
>child process which is a filter, this can be done by using temporary
>files.  See the MS-DOS implementation of gawk (you can get it at any
>GNU mirror, eg wuarchive.wustl.edu).  It doesn't work quite right "out
>of the box" (it was intended for I think Turbo and MSC) but the mods
>needed for djgpp are obvious and take about fifteen minutes (look for
>"#ifdef MSDOS").

Attached is a popen() implementation which can be used by those who
- as mentioned above - do not need real pipes.

Peter Crowley
Quarterdeck Offices Systems
pcrowley AT qdeck DOT com

The following is an attached File item from cc:Mail.  It contains
eight bit information which had to be encoded to insure successful trans-
mission through various mail systems.  To decode the file use the UUDECODE
program.
--------------------------------- Cut Here ---------------------------------
begin 644 PIPE.C
M+RH@<&]P96XO<&-L;W-E('-U<'!O<G0 AT 9F]R($U31$]3("HO#0HO*BHJ*BHJ
M*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ
M*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ#0H-"B`@0V]P>7)I9VAT(#$Y.3,@475A<G1E
M<F1E8VL AT 3V9F:6-E(%-Y<W1E;7,-"B`@06QL(%)I9VAT<R!297-E<G9E9`T*
M#0H@(%!E<FUI<W-I;VX@=&\@9G)E96QY('5S92P AT 8V]P>2P@;6]D:69Y+"!A
M;F0 AT 9&ES=')I8G5T92!T:&ES#0H@('-O9G1W87)E(&9O<B!A;GD@<'5R<&]S
M92!I<R!H97)E8GD AT 9W)A;G1E9"P@<')O=FED960@=&AA="!T:&4-"B`@86)O
M=F4 AT 8V]P>7)I9VAT(&YO=&EC92!A<'!E87(@:6X AT 86QL(&-O<&EE<R!O9B!T
M:&4@<V]F='=A<F4N#0H@(%%U87)T97)D96-K($]F9FEC92!3>7-T96US(&ES
M(&YO="!R97-P;VYS:6)L92!F;W(@86YY(&1A;6%G97,-"B`@<F5S=6QT:6YG
M(&9R;VT@=&AE('5S92!O9B!T:&ES('-O9G1W87)E+@T*#0HJ*BHJ*BHJ*BHJ
M*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ*BHJ
M*BHJ*BHJ*BHJ*BHJ*BHO#0H-"B-I;F-L=61E(#QS=&1I;RYH/@T*(VEN8VQU
M9&4@/&UA;&QO8RYH/@T*(VEN8VQU9&4@/&9C;G1L+F@^#0HC:6YC;'5D92`\
M<W1R:6YG+F@^#0H-"G-T871I8R!S=')U8W0@>PT*"6-H87(@*G!R;V<[#0H)
M8VAA<B`J;F%M93L-"GT@*G!I<&5S(#T AT 3E5,3#L-"G-T871I8R!I;G0 AT 9F1M
M87@@/2`M,3L-"@T*<W1A=&EC('!I<&5?<F5M96UB97(H1DE,12`J+"!C;VYS
M="!C:&%R("HL(&-H87(@*BD[#0H-"D9)3$4@*G!O<&5N*&-O;G-T(&-H87(@
M*G!R;V<L(&-O;G-T(&-H87(@*FUO9&4I#0I[#0H)1DE,12`J<F5T.PT*"6EN
M="!F9#L-"@EI;G0@<F,[#0H)8VAA<B!T;7!;3%]T;7!N86U=.PT*#0H):68H
M*FUO9&4@/3T@)W(G*2![#0H)"6EN="!S879E7W-T9&]U=#L-"@D)#0H)"2AV
M;VED*71M<&YA;2AT;7`I.PT*"0EF9"`](&]P96XH=&UP+"!/7U)$5U)\3U]#
M4D5!5"P@,#8P,"D[#0H)"6EF*&9D(#P@,"D@<F5T=7)N($Y53$P[#0H-"@D)
M<V%V95]S=&1O=70@/2!D=7`H,2D[#0H)"61U<#(H9F0L(#$I.PT*"0EC;&]S
M92AF9"D[#0H-"@D)<F,@/2!S>7-T96TH<')O9RD[#0H-"@D):68H<F,@/CT@
M,"D AT 9F0@/2!D=7`H,2D[#0H)"61U<#(H<V%V95]S=&1O=70L(#$I.PT*"0EC
M;&]S92AS879E7W-T9&]U="D[#0H)"6EF*')C(#P@,"D@<F5T=7)N($Y53$P[
M#0H-"@D)<F5T(#T AT 9F1O<&5N*&9D+"`B<B(I.PT*"0EI9B AT A<F5T*2![#0H)
M"0EC;&]S92AF9"D[#0H)"0ER96UO=F4H=&UP*3L-"@D)"7)E='5R;B!.54Q,
M.PT*"0E]#0H-"@D)<F5W:6YD*')E="D[#0H-"@D):68H<W1R8VAR*&UO9&4L
M("=B)RDI('-E=&UO9&4H9F0L($]?0DE.05)9*3L-"@T*"0EI9B AT A<&EP95]R
M96UE;6)E<BAR970L("AC:&%R("HI3E5,3"P@=&UP*2D@>PT*"0D)9F-L;W-E
M*')E="D[#0H)"0ER96UO=F4H=&UP*3L-"@D)"7)E='5R;B!.54Q,.PT*"0E]
M#0H)"7)E='5R;B!R970[#0H)?2!E;'-E(&EF*"IM;V1E(#T]("=W)RD@>PT*
M"0DH=F]I9"ET;7!N86TH=&UP*3L-"@T*"0ER970@/2!F;W!E;BAT;7`L(")W
M*R(I.PT*"0EI9B AT A<F5T*2!R971U<FX AT 3E5,3#L-"@T*"0EI9BAS=')C:'(H
M;6]D92P@)V(G*2D@<V5T;6]D92AF:6QE;F\H<F5T*2P AT 3U]"24Y!4EDI.PT*
M#0H)"6EF*"%P:7!E7W)E;65M8F5R*')E="P@<')O9RP@=&UP*2D@>PT*"0D)
M9F-L;W-E*')E="D[#0H)"0ER96UO=F4H=&UP*3L-"@D)"7)E='5R;B!.54Q,
M.PT*"0E]#0H)"7)E='5R;B!R970[#0H)?2!E;'-E(')E='5R;B!.54Q,.PT*
M?0T*#0IS=&%T:6,@<&EP95]R96UE;6)E<BA&24Q%("IF+"!C;VYS="!C:&%R
M("IP<F]G+"!C:&%R("IN86UE*0T*>PT*"6EN="!F9#L-"@T*"69D(#T AT 9FEL
M96YO*&8I.PT*#0H):68H9F0@/B!F9&UA>"D@>PT*"0EF9&UA>"`](&9D("L@
M,3L-"@D):68H<&EP97,I('L-"@D)"7!I<&5S(#T@<F5A;&QO8RAP:7!E<RP@
M9F1M87@@*B!S:7IE;V8H*G!I<&5S*2D[#0H)"7T AT 96QS92![#0H)"0EP:7!E
M<R`](&UA;&QO8RAF9&UA>"`J('-I>F5O9B AT J<&EP97,I*3L-"@D)?0T*"0EI
M9B AT A<&EP97,I(&=O=&\@9F%I;#L-"@E]#0H-"@EI9BAP<F]G*2![#0H)"7!I
M<&5S6V9D72YP<F]G(#T@<W1R9'5P*'!R;V<I.PT*"0EI9B AT A<&EP97-;9F1=
M+G!R;V<I(')E='5R;B`P.PT*"7T AT 96QS92![#0H)"7!I<&5S6V9D72YP<F]G
M(#T AT 3E5,3#L-"@E]#0H-"@EI9BAN86UE*2![#0H)"7!I<&5S6V9D72YN86UE
M(#T@<W1R9'5P*&YA;64I.PT*"0EI9B AT A<&EP97-;9F1=+FYA;64I(&=O=&\@
M9F%I;#L-"@E](&5L<V4@>PT*"0EP:7!E<UMF9%TN;F%M92`]($Y53$P[#0H)
M?0T*#0H)<F5T=7)N(#$[#0H-"F9A:6PZ#0H)9G)E92AP:7!E<UMF:6QE;F\H
M9BE=+G!R;V<I.PT*"7)E='5R;B`P.PT*?0T*#0IP8VQO<V4H9BD-"D9)3$4@
M*F8[#0I[#0H):6YT(&9D.PT*#0H)9F0@/2!F:6QE;F\H9BD[#0H-"@EI9BAF
M+3Y?9FQA9R`F("A?24]74E1\7TE/4E<I*2![#0H)"6EN="!S879E7W-T9&EN
M.PT*#0H)"7)E=VEN9"AF*3L-"@T*"0ES879E7W-T9&EN(#T AT 9'5P*#`I.PT*
M"0ED=7`R*&9D+"`P*3L-"@D)9F-L;W-E*&8I.PT*#0H)"2AV;VED*7-Y<W1E
M;2AP:7!E<UMF9%TN<')O9RD[#0H)"69R964H<&EP97-;9F1=+G!R;V<I.PT*
M#0H)"61U<#(H<V%V95]S=&1I;BP@,"D[#0H)"6-L;W-E*'-A=F5?<W1D:6XI
M.PT*"7T AT 96QS92![#0H)"69C;&]S92AF*3L-"@E]#0H-"@EI9BAP:7!E<UMF
M9%TN;F%M92D@>PT*"0ER96UO=F4H<&EP97-;9F1=+FYA;64I.PT*"0EF<F5E
;*'!I<&5S6V9D72YN86UE*3L-"@E]#0I]#0H:
`
end