Before actually using GUI dialogues, consider using console prompts. Quite often you can get away with simple “y/n?” prompts, which in bash you achieve via the read command.. read -p “Do something? “; if [ $REPLY == “y” ]; then echo yay; fi If console prompt’s just won’t cut it, Zenity is really easy to … Read more
If you are using Tcl 8.6, you can trap all the output to stdout by adding a suitable transform via chan push: # Use a class to simplify the capture code oo::class create CapturingTransform { variable var constructor {varName} { # Make an alias from the instance variable to the global variable my eval [list … Read more
If you cannot change your code to take the name of a channel to write to (the most robust solution), you can use a trick to redirect stdout to a file: reopening. proc foo {} { puts “hello world” } proc reopenStdout {file} { close stdout open $file w ;# The standard channels are special … Read more
The code should read the contents of the two files into lists of lines, then iterate over them. It ends up like this: # Set up various other variables here ($user, $password) # Get the list of hosts, one per line ##### set f [open “host.txt”] set hosts [split [read $f] “\n”] close $f # … Read more
If you want to wait for jobs to finish, use wait. This will make the shell wait until all background jobs complete. However, if any of your jobs daemonize themselves, they are no longer children of the shell and wait will have no effect (as far as the shell is concerned, the child is already … Read more
Though you’re running a subsidiary event loop (really don’t do that!) it still shares the same registry of event handlers as the outer loop, so events coming in are handled in the inner loop just as in the outer one. (There’s a common piece of low-level event handling code that reaches deep into the OS … Read more
To make a gridded layout have all columns have the same width, you’ve got to configure those columns to have the same weight and to be in the same uniform group. This configuration is associated with the master widget, not any of the contained widgets (because columns can contain many widgets, of course). In standard … Read more
According to the “How Python Chooses Which Tk Library To Use” section of the “IDLE and tinter with Tcl/Tk on Mac OS X” page on the official python website, The Python for Mac OS X installers downloaded from this website dynamically link at runtime to Tcl/Tk Mac OS X frameworks. The Tcl/Tk major version is … Read more
Use tail’s –pid option and tail will stop when the shell dies. No need to add extra to the tailed file. sh -c ‘tail -n +0 –pid=$$ -f /tmp/foo | { sed “/EOF/ q” && kill $$ ;}’
The “problem” with expr is that it implements its own “mini language”, which includes, among other things, variable substitution (replacing those $a-s with their values) and command substitution (replacing those [command …] things with the results of running commands), so basically the process of evaluating expr $a + $b goes like this: The Tcl interpreter … Read more