printf不常见用法
Wednesday, April 25, 2012 7:13:39 AM
$ printf '%+08d' 42
+0000042
$ printf '%*.*s' 8 4 hello
hell
$ printf "%'.2f" 123456.789
123,456.79
$ printf '%b' 'hello\tworld'
hello world
$ printf '%x' "'B"
42
$ printf '%2$s %1$s' world hello
hello world

