bash脚本:如果参数等于此字符串,则定义一个类似于此字符串的变量

Question

我正在做一些bash脚本,现在我有一个变量调用source和一个数组调用samples,如下所示:

source='country'
samples=(US Canada Mexico...)

因为我想扩展源的数量(并且每个源都有自己的样本)我试图添加一些参数来做到这一点.我试过这个:

source=""
samples=("")
if [ $1="country" ]; then
   source="country"
   samples="US Canada Mexico..."
else
   echo "try again"
fi

但是当我运行我的脚本时source countries.sh country它没有用.我究竟做错了什么？

Answer 1

不要忘记空格:

source=""
samples=("")
if [ $1 = "country" ]; then
   source="country"
   samples="US Canada Mexico..."
else
  echo "try again"
fi

Answer 2

您可以使用"="或"=="运算符在bash中进行字符串比较.重要因素是括号内的间距.正确的方法是使括号内部包含间距,并使操作符包含间距.在某些情况下,不同的组合有效 但是,以下内容旨在成为一个普遍的例子.

if [ "$1" == "something" ]; then     ## GOOD

if [ "$1" = "something" ]; then      ## GOOD

if [ "$1"="something" ]; then        ## BAD (operator spacing)

if ["$1" == "something"]; then       ## BAD (bracket spacing)

另外,与单支架相比,注意双支架的处理方式略有不同......

if [[ $a == z* ]]; then   # True if $a starts with a "z" (pattern matching).
if [[ $a == "z*" ]]; then # True if $a is equal to z* (literal matching).

if [ $a == z* ]; then     # File globbing and word splitting take place.
if [ "$a" == "z*" ]; then # True if $a is equal to z* (literal matching).

我希望有所帮助!

Answer 3

您似乎希望将命令行参数解析为bash脚本.我最近自己搜索过这个.我遇到了以下内容,我认为这将有助于您解析参数:

http://rsalveti.wordpress.com/2007/04/03/bash-parsing-arguments-with-getopts/

我在下面添加了片段作为tl;博士

#using : after a switch variable means it requires some input (ie, t: requires something after t to validate while h requires nothing.
while getopts “ht:r:p:v” OPTION
do
     case $OPTION in
         h)
             usage
             exit 1
             ;;
         t)
             TEST=$OPTARG
             ;;
         r)
             SERVER=$OPTARG
             ;;
         p)
             PASSWD=$OPTARG
             ;;
         v)
             VERBOSE=1
             ;;
         ?)
             usage
             exit
             ;;
     esac
done

if [[ -z $TEST ]] || [[ -z $SERVER ]] || [[ -z $PASSWD ]]
then
     usage
     exit 1
fi

./script.sh -t test -r server -p password -v