a part of stdio, this file is opened by default for each application making use of the stdio package of code.
This input file may correspond to a disk file, pipe, terminal device, or other construct.
To refer to the stdin filehandle in Tcl, use the string stdin when using gets .
A quite distinct use of the same word refers to the stdin package Stephen Uhler includes with tclhttpd.
An example of reassigning stdin and providing a prompt and capturing user input for tclsh.
#!/usr/bin/tclsh
# by Mike Tuxford
#
# the handler for stdin
proc localHandler {} {
# get the data from stdin
gets stdin data
# client will exit if you type "exit". How original!
if {$data == "exit"} {
exit
} else {
# process your data here, or pass it to another proc
# or pass it to a local/remote server
# return a new pseudo-prompt
puts -nonewline stdout \
"[clock format [clock seconds] -format "%H:%M:%S"] Tcl> "
flush stdout
}
return
}
# assign our event handler for stdin
fileevent stdin readable localHandler
# send a startup message and initial prompt
puts -nonewline stdout \
"Tcl pseudo-prompt activated... \
\n[clock format [clock seconds] -format "%H:%M:%S"] Tcl> "
flush stdout
# enter the tcl event loop
vwait __forever__You can even use it with inetd for an instant TCP/IP server:
in your services file:
test 10000/tcp
in your /etc/inetd.conf:
test stream tcp /home/user/develop/program.tcl program.tcl
Then in your program just read stdin like above and that's it!
SB: Turn off buffering on stdout to use repetitive -nonewline in interactive input with tclsh:
fconfigure stdout -buffering none puts -nonewline "Give me your input: " gets stdin first puts -nonewline "Give me another input: " gets stdin second puts "First you told me $first and then $second"
MC: Using "gets stdin myVar" doesn't WAIT for the user to enter stuff...
it simply reads from the stdin stream. Any idea how to make it wait? I tried: while {gets stdin myVar < 0} {} This works...but of course takes 100% CPU.. .ew.