delete specific character "[" from a file
[ character is special as it starts a
[...] group (a bracketed expression).
sed on OpenBSD, your command gives a more helpful error message:
$ sed 's/[//g' sed: 1: "s/[//g": unbalanced brackets ()
To delete all
[ characters using
sed, escape it:
sed -i 's/\[//g' file
Or put it inside a bracketed expression:
sed -i 's/[//g' file
tr -d '[' <file >file.new
Also, don't use in-place editing with
sed until you know the expression that you are trying out actually works, or you will possibly have to restore your data from backups.