brian foster blfutvinternetie date sat 20 jul 2002 104736 0100 stephen shirley easy get one program act output second program cmd1 cmd2 want cmd1 act output cmd2 well hmm eventually came solution mkfifo io cmd1 io bingo well world sneaking suspcion might possible without using fifo done using something like 1 exec 31 2 cmd1 3 cmd2 3 3 exec 3 doesnt work form couldnt work incantation would anyone got suggestions something close would work 1st line executed file descriptor fdesc 1 open read write rw suitable entity eg pipefifo imagine socket something ilk could made work idea youd want go trouble case unlikely case probably fdesc 1 yer tty eg screen keyboard quite possibly open write stdout need open rw dup22 nm means replicate fdesc handle change access mode eg original fdesc open writing w thats new fdesc n open yet 2nd line needed r cmd1 w cmd2 whilst impossible say certain excerpt seems reasonable guess fdesc 1 1st line executes stdout script probably yer tty means happen open rw case systems cmd2 would writing screen whilst cmd1 reading keyboard ie poor confused human luser clearly expected manually echo back computer prints good luck upshot fifo needed isnt shell scripting problem per se fifo solution fine ive used variations plural approach extend korn ksh1 shell language providing coprocessing interpreter ksh sends certain predefined commands coprocess handling control coprocess indicates processing complete ksh resume normal processing thought care insure signals something rational works great adding scripting language purpose cheaply scriptless programs useful cant modify imho buggy program use eg tcl cheers blf innovative experienced unix brian foster dublin ireland chorus embedded rtos kernel internals email blfutvinternetie expert looking new position mobile 353 086 854 9268 résumé contact see website httpwwwblfutvinternetie stop eo exxonmobile whatever dont buy esso dont give damn global warming httpwwwstopessocom supported greenpeace friends earth numerous others irish linux users group iluglinuxie httpwwwlinuxiemailmanlistinfoilug unsubscription information list maintainer listmasterlinuxie sun 21 jul 2002 020201 0100 ilug vanquishing daemons shell scripting