How can I find the binary that is executed when entering a command?
I just have installed TeX-Live 2012, but I still get
moose@pc07:~$ latex --version
pdfTeX 3.1415926-1.40.10-2.2 (TeX Live 2009/Debian)
kpathsea version 5.0.0
Copyright 2009 Peter Breitenlohner (eTeX)/Han The Thanh (pdfTeX).
There is NO warranty. Redistribution of this software is
covered by the terms of both the pdfTeX copyright and
the Lesser GNU General Public License.
For more information about these matters, see the file
named COPYING and the pdfTeX source.
Primary author of pdfTeX: Peter Breitenlohner (eTeX)/Han The Thanh (pdfTeX).
Compiled with libpng 1.2.42; using libpng 1.2.42
Compiled with zlib 1.2.3.3; using zlib 1.2.3.3
Compiled with poppler version 0.12.4
So I've wondered if I could find out where the binary that gets executed when I enter latex --version is located. Is this possible?
Solution 1:
You can use
which latex
to find out the location of a binairy.
Solution 2:
The type command is built-in to bash (which is a standalone program).
type latex
The type command can also differentiate between shell aliases, shell functions and standalone programs if you pass the -a option: I have an alias for ls
$ type -a ls
ls is aliased to `ls -F'
ls is /bin/ls
Solution 3:
For simple stand-alone commands the above answers are perfectly correct. However, if you are running complex scripts and you want to know what's happening behind the scenes, the best way is always:
ps afxu
that displays the entire tree of command being executed.
For example, running ps afxu while updating grub2 with os-prober enabled produces this output:
root 4304 0.0 0.0 27308 1700 ? Ss 16:33 0:00 SCREEN -S update-grub
root 4305 0.9 0.1 23540 4648 pts/2 Ss 16:33 0:00 \_ /bin/bash
root 4371 0.0 0.0 4392 744 pts/2 S+ 16:33 0:00 \_ /bin/sh /usr/sbin/grub-mkconfig -o /boot/grub/grub.cfg
root 5127 0.0 0.0 4396 756 pts/2 S+ 16:33 0:00 \_ /bin/sh /etc/grub.d/30_os-prober
root 7029 0.0 0.0 4396 176 pts/2 S+ 16:33 0:00 \_ /bin/sh /etc/grub.d/30_os-prober
root 7030 0.0 0.0 4396 464 pts/2 S+ 16:33 0:00 \_ /bin/sh /etc/grub.d/30_os-prober
root 7038 0.0 0.1 23660 4676 pts/2 D+ 16:33 0:00 | \_ /usr/sbin/grub-probe --device /dev/sdb3 --target=fs_uuid
root 7031 0.0 0.0 11520 828 pts/2 S+ 16:33 0:00 \_ sed -e s/^/\t/
In this way you can know exactly what is being called by an executable/script in each phase of its execution.