processHistograms

[soliday]

When you type "which tclsh" do you get /usr/bin/tclsh
When you type "ls -l /usr/bin/tclsh" do you get "/usr/bin/tclsh -> tclsh8.6"

I would try forcing a reinstall of tcl
sudo apt-get --reinstall install tcl

[Aamna_Khan]

Now tclsh is working fine. I installed it from the source.

I tested oagtclsh it's there. While using processHistogram I end up with the same error where I started it.

[soliday]

Run:
oagtclsh
load /usr/share/tcltk/os/libtclOS.so

That should return with no errors, if not let me know what they are.

If it returned with no errors then my guess is that because you installed it from source, you probably have a different installation directory than the standard system version. You will need to copy the directories:
/usr/share/tcltk/ca
/usr/share/tcltk/os
/usr/share/tcltk/sdds
/usr/share/tcltk/rpn
to the the package path for your installation of tclsh. You can find this by running tclsh and "puts $tcl_pkgPath"
My version has a package path of:
/usr/local/lib/tcltk /usr/local/share/tcltk /usr/lib/tcltk/x86_64-linux-gnu /usr/lib/tcltk /usr/share/tcltk /usr/lib/tcltk/tcl8.6 /usr/lib
I suspect yours will be different and missing the /usr/share/tcltk entry.

[Aamna_Khan]

Thank you so much. You were right I was missing the /usr/share/tcltk entry in the tclsh package path.

/Aamna