Question

When calling script as

tclsh ./TestDriver.tcl TestList

the tcl script stops after one (?) line. But when called with output redirected to a file

tclsh ./TestDriver.tcl TestList >bar.out

it runs smoothly.
Any ideas what might be the cause of such behavior ?

Answer 1

Almost all Tcl scripts work identically when their output is directed to a terminal or to a file. While there is a tcl_interactive variable that things could be keyed off, it doesn’t come into play when you’re supplying the script as an argument. The other base-line difference is that stdout will have different buffering by default; you can change that to be defined with:

fconfigure stdout -buffering none ;# Or “line” or “full”

However, I would expect the differences there to make things (very marginally) less likely to work in the case of being redirected to a file. Whatever is going on (and I bet it either involves running subprocesses or the use of extension packages) I can’t guess it on the basis of the evidence provided.