tty

I want my ksh script to have different behaviors depending on whether there is something incoming through stdin or not: (1) cat file.txt | ./script.ksh (then do "cat <&0 >./tmp.dat" and process tmp.dat) vs. (2) ./script.ksh (then process $1 which must be a readable regular file) Checking for stdin to see if it is a terminal[ -t 0 ] is not helpful, because my script is called from an other script. Doing "cat <&0 >./tmp.dat" to check tmp.dat's size hangs up waiting for an EOF from stdin if stdin is "empty" (2nd case). How to just check if stdin is "empty" or not?! vladr EDIT: You are running on

I am using R to generate a series of plots within a loop, with the user hitting the enter key to indicate they have seen the plot and it is time to move on. These are interactive rotatable plots generated with the rgl package and therefore using something like Sys.sleep() is not good enough. Currently I can use readline() which works find when running R interactively. However, if I want to run my R script within a bash script all the plots appear flashing before the screen. This happens whether I call R using: R --no-save -f myfile.r R --no-save -e "source('myfile.r')" R --no-save << myfile.r

I used to linux USB port naming, aka /dev/ttyUSBxx and currently trying to write some test software to read/wrtie raw data to USB ports on iMac, but i find it hard to detect to which port my usb hardware is connected. I have tried up to a using /dev/ttys"x" but no luck. In the system information i see the hardware attached at Location ID: 0xfa120000 / 6 maybe this can help somehow? OS X doesn't create a /dev entry for raw access to USB devices, and there's no way to access them as TTY devices. Partly this is a different in philosophy between Linux and BSD, partly it's a difference in driver

What are the differences between this two examples? #!/usr/bin/perl use warnings; use 5.012; my $str = "\x{263a}"; open my $tty, '>:encoding(utf8)', '/dev/tty' or die $!; say $tty $str; close $tty; open $tty, '>:bytes', '/dev/tty' or die $!; say $tty $str; close $tty; # ------------------------------------------------------- binmode STDOUT, ':encoding(utf8)' or die $!; say $str; binmode STDOUT, ':bytes' or die $!; say $str; The difference is that you are writing to two distinct and (from Perl's and your program's point of view) independent file handles. The first one is a file handle opened to