Linux 脚本中的模块加载/卸载命令

Question

I often have a need to create Linux scripts which contain module load and module unload commands. Is there a way to test if a module is already loaded before executing a module unload command?

The reason why I need to do this is that if I have a module unload command and the module in question is not already loaded, then it will result in error messages. I would like to avoid these error messages by testing for the module being already loaded, and unloading it only if this is the case.

Answer 1

Recent versions of the module command (4+) have a new sub-command called is-loaded which returns true or false whether a given module is loaded or not.

So to conditionally unload a module from a shell session, you could type:

module is-loaded $MODULENAME && module unload $MODULENAME

Answer 2

Assuming the question is not related to Linux modules but to this software: https://modules.readthedocs.io/en/stable/module.html

The grep pattern assumes that the module name is the first word of the module list output. This will be fixed when the missing information is added to the question.

# example for unloading
MODULENAME=foobar
module list | grep -qw "^$MODULENAME" && module unload "$MODULENAME"

# example for loading
MODULENAME=foobar
module list | grep -qw "^$MODULENAME" || module load "$MODULENAME"

Answer 3

OK I think the answer of Bodo is close but this is tricky because at least my module command prints to the error output but I think OK solution for loading modules would be:

function LoadModule()
{
    if module list 2>&1| grep -qw $1; then
        echo "Module $1 already loaded."
    else
        echo "Loading module $1."
        module load $1
    fi
}

function UnloadModule()
{
    if module list 2>&1| grep -qw $1; then
        echo "Unloading module $1."
        module unload $1
    else
        echo "Module $1 is not loaded."
    fi
}