Question

When you build Tcl/Tk by default it creates the files

tclsh85
wish85

However many programs call tclsh and wish. This is one fix for that

cp tclsh85 tclsh
cp wish85 wish

However, can you simply build tclsh and wish directly, perhaps using a configure argument?

Answer 1

This behavior is The Right Thing as it allows several versions of the interpreter and its libraries to coexist in the system. The system, in turn, does provide a way to “bless” one of the version as “default” — for instance, Debian provides “alternatives”. In essence, usually a symlink with the “canonical” name is created pointing to the real executable, like /usr/bin/tclsh → /usr/bin/tclsh85. And with the “blessed” version available via such a symlink for the applications that do not care about the precise version of the runtime, certain other applications still can pick some specific runtime version by referring to the interpreter’s real executable name.

This also provides an easy way to test an existing program against an experimental runtime version: you just run /usr/bin/tclsh86 /path/to/the/script.tcl instead of just running /path/to/the/script.tcl as usually which relies on the shebang to pick the interpreter.