mjhjmtu

I am passing a set of 6 arguments initially to a script.

Script.sh a b c d e f

One of the commands in the script which is managing the arguments;

comm=$(echo $1 |sed 's/~/ /g')

The sed expression s/~/ /g replaces every tilde with a space character. It means, literally, "substitute everything that matches the regular expression ~ with a space, globally (on the whole input line)". The expression could in this case also have been written as y/~/ /, and the whole sed command could be replaced by the faster tr '~' ' '.

In bash, this is more efficiently done with

comm=$1//~/ 

The ~ has to be escaped here to not be expanded to the pathname of the current user's home directory.

In any case, the $1 needs to be double quoted if you are using it with echo (unless you want the tilde to be interpreted as someone's home directory, and other shell globs to be expanded to filenames), and ideally, the command would be written with printf (this avoids an initial dash in $1 from being interpreted as the start of some option to echo):

comm=$( printf '%sn' "$1" | tr '~' ' ' )

Related:

• Why is printf better than echo?


• Why does my shell script choke on whitespace or other special characters?