delete a column with awk or sed
This might work for you (GNU sed):
sed -i -r 's/\S+//3' file
If you want to delete the white space before the 3rd field:
sed -i -r 's/(\s+)?\S+//3' file
With GNU awk for inplace editing, \s/\S, and gensub() to delete
1) the FIRST field:
awk -i inplace '{sub(/^\S+\s*/,"")}1' file
or
awk -i inplace '{$0=gensub(/^\S+\s*/,"",1)}1' file
2) the LAST field:
awk -i inplace '{sub(/\s*\S+$/,"")}1' file
or
awk -i inplace '{$0=gensub(/\s*\S+$/,"",1)}1' file
3) the Nth field where N=3:
awk -i inplace '{$0=gensub(/\s*\S+/,"",3)}1' file
Without GNU awk you need a match()+substr() combo or multiple sub()s + vars to remove a middle field. See also Print all but the first three columns.
try this short thing:
awk '!($3="")' file