bash script 常用技能备忘

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 outstr
echo $outstr # $outstr == "abcdef" now