摘要：SHELL printf Format Directives中有一项是: \NNN character with octal value NNN (1 to 3 digits) "NNN"是个三位数字表示的八进制数， 如：八进制数101表示... 阅读全文

摘要：${var:-DEFAULT}和${var=DEFAULT}的区别： ${var:-DEFAULT} If var not set or is empty, evaluate expression as $DEFAULT ${var=DEFAULT} If var not set, evaluate... 阅读全文