赋值

x="abc"   # = 前后不能有空格

条件判断

if cond; then       # some code   elif cond2; then       # some code   fi   if [ "$a" == "x" ]; then        # 空格不能少   if oscommand ; then           # oscommand 成功，返回0, oscommand 也返回true, 否则返回false   example:   if echo "abc" | grep -q ab; then

function

function f() {       echo "f" $1  # $1 为第一个参数   }   f "par1"  # 调用函数f,  注意没有括号   function g() {       eval "$1='abcdef '"   }outstr=''g outstrecho $outstr  # $outstr == "abcdef" now