sed/awk删除文件奇数行或偶数行

sed '1~2d'  file > new_file # 删除奇数行
sed '1~2!d' file > new_file # 删除偶数行

awk 'NR%2==0' filename > new_file # 删除奇数行
awk 'NR%2==1' filename > new_file # 删除偶数行