windows

Tcl/Tk experiments.

Conventions

Put program entrypoint scripts in bin and supporting code in lib. Any program in bin can inlude the following line to locate libraries in lib.

lappend auto_path \
    [file join [file dirname [info script]] ../lib/foolib]

auto_path is a global runtime variable, a list of directories. Each is recursively searched for Tcl packages.

Packages in lib must include a package provide line

package provide foo 2.1

Two scripts can implement the same package if they provide the same package name and version.

A package or script can declare a dependency on another package with require.

package require foo 2.1 

Unfortunately, existing on the auto_path is not enough for packages to be found by require. A pkgIndex.tcl file must be built by running a special indexing command in Tcl.

pkg_mkIndex /some/lib *.tcl

Our build script can do this for us is broken, so we must write pkgIndex.tcl files by hand for each custom library.

Interactive commands

Try these fascinating commands at the tclsh command line

info tclversion
info commands

Nicer shell

The default tclsh and wish are super stripped down, and don't even provide command history. To become a cool person, install tclreadline, and add the following to ~/.tclshrc

package require tclreadline

proc ::tclreadline::prompt1 {} {
    return "[lindex [split [info hostname] "."] 0] [lindex [split [pwd] "/"] end] % "
}

::tclreadline::Loop

Getting more sweet packages

You will probably need to use your system package manager. On Arch, search the official repositories like

pacman -Ss sqlite | grep tcl

Misc

• some info on dictionaries