When I run
$ latex my_doc.tex
$ pdflatex my_doc.tex
it works, and when I run
$ pdftex my_doc.tex
it doesn't work.
The thing is I noticed that both
pdflatex commands are symbolic links to the same
pdftex executable. That is,
$ which latex pdflatex pdftex
/usr/bin/latex /usr/bin/pdflatex /usr/bin/pdftex
$ ls -l /usr/bin/latex /usr/bin/pdflatex /usr/bin/pdftex
/usr/bin/latex -> pdftex /usr/bin/pdflatex -> pdftex /usr/bin/pdftex
So how is it possible that commands being symbolic links to a same executable do not behave in the same way ?
Ubuntu 12.10 with TeXLive-full 2012.20120611-4 installed.