Re: [netrexx-pipelines] Strangeness when filtering linux stty output

[Marc R. <re...@gm...>]

Leslie,

pipe 'command stty --all|console also runs fine.. Its output is empty because it is not connected to a real/pseudo terminal, as echo dog |tty reports.

Indeed, we're not doing bash redirection, it is now java that is doing the redirection.
The command stage starts the stty process by r.exec and connects to its stdin.
For the stty process there's no difference whether the redirection is done by bash or java, in both cases its stdin is not a terminal. And thus stty has no effect.

Marc


On 7/31/23 16:00, J Leslie Turriff wrote:
> On 2023-07-31 06:20:50 Marc Remes wrote:
>> On 7/31/23 13:03, Rony G. Flatscher wrote:
>>> According to "https://linux.die.net/man/1/stty" "stty --all" would print
>>> all settings (to stdout I assume).
>>
>> True :
>>
>> $ stty --all
>> speed 38400 baud; rows 30; columns 99; line = 0;
>> intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2
>> = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
>> werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0;
>> -parenb -parodd -cmspar cs8 -hupcl -cstopb cread -clocal -crtscts
>> -ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon
>> -ixoff -iuclc -ixany -imaxbel iutf8
>> opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0
>> ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop
>> -echoprt echoctl echoke -flusho -extproc
>> $ echo dog | stty
>> stty: 'standard input': Inappropriate ioctl for device
>>
>> The first command is attached to a terminal (either a 'real' terminal, but
>> more likely a pseudo-terminal), and shows its settings. The second
>> command's stdin is the stdout of the echo command, and says so..
>>
>> Also check the tty command:
>> $ tty
>> /dev/pts/6
>> $ echo dog | tty
>> not a tty
>>
>> Marc
>>
> 	But:
> 
> | @08:49:08 ─▶leslie@pinto◀─
> | wd=~/bin/NetRexx/Pipelines
> | $ pipe 'command ls -l|console'
> | total 224
> | -rw-r--r-- 1 leslie users  3741 Jun 29 01:44 condense.class
> | -rw-r--r-- 1 leslie users  1298 Jun 29 00:07 GenSymLinks.class
> | -rw-r--r-- 1 leslie users  4688 Jun 28 23:53 GenSymLinks_gensymlinks.class
> |    :
> | -rw-r--r-- 1 leslie users  2403 Jun 19 15:50 treeOutput.txt
> | rc=0
> 
> works just fine, whereas
> 
> | @08:49:20 ─▶leslie@pinto◀─
> | wd=~/bin/NetRexx/Pipelines
> | $ pipe 'command stty --all|console'
> | rc=0
> 
> produces no output.  What is the difference between the stage "command ls -l"
> (which works) and "command stty --all" (which does not)?  We're not doing
> bash redirection here; this is inside the NetRexx pipeline.
> 
> Leslie