reproduce: $ printf "1This is a test\t3This is test too\t5And more test\n2测试一是这样\t4测试二如此\t6测试三，嗯。\n" | expand -t 12 1This is a test 3This is test too 5And more test 2测试一是这样 4测试二如此 6测试三，嗯。
expected: $ printf "1This is a test\t3This is test too\t5And more test\n2测试一是这样\t4测试二如此\t6测试三，嗯。\n" | expand -t 12 1This is a test 3This is test too 5And more test 2测试一是这样 4测试二如此 6测试三，嗯。 Note that your email software must be able to show ideograph correctly in order to see the problem. Note that other coreutils do not suffer from this problem. Take ls for example: $ touch "1This is a test" "2测试一是这样" "3This is test too" "4测试二如此" "5And more test" "6测试三，嗯。" 2$ ls 1This is a test 3This is test too 5And more test 2测试一是这样 4测试二如此 6测试三，嗯。 So you see ls(1) output have ideograph width correctly calculated. So I can guess that simply taking the width calculation routine of ls(1) and use it in expand would solve the problem.
