[gmx-users] extracting trajectory using trjconv

[Hadi Rahmaninejad]

Hello Gromacs Users,

I am going to use "trjconv" to extract trajectory from a .trr file. Here is
my command:
"gmx trjconv -f x.trr -s x.gro -o frames.gro"
then it gives me the options to choose my group, but I wanna it choose for
me automatically, as I am going to extract from a lot of simulations using
a loop. In another word, I need to give it the name of my projectile
molecule in the command line. Can anybody help me with this?

Thank you in advance,
Hadi