arglist.sh

BASH Shell 编程 经典教程 《高级SHELL脚本编程》中文版

#!/bin/bash
# arglist.sh
# 多使用几个参数来调用这个脚本, 比如"one two three".

E_BADARGS=65

if [ ! -n "$1" ]
then
  echo "Usage: `basename $0` argument1 argument2 etc."
  exit $E_BADARGS
fi  

echo

index=1          # 起始计数.

echo "Listing args with \"\$*\":"
for arg in "$*"  # 如果"$*"不被""引用,那么将不能正常地工作.
do
  echo "Arg #$index = $arg"
  let "index+=1"
done             # $* 将所有的参数看成一个单词.
echo "Entire arg list seen as single word."

echo

index=1          # 重置计数(译者注: 从1开始).
                 # 如果你写这句会发生什么?

echo "Listing args with \"\$@\":"
for arg in "$@"
do
  echo "Arg #$index = $arg"
  let "index+=1"
done             # $@ 把每个参数都看成是单独的单词.
echo "Arg list seen as separate words."

echo

index=1          # 重置计数(译者注: 从1开始).

echo "Listing args with \$* (unquoted):"
for arg in $*
do
  echo "Arg #$index = $arg"
  let "index+=1"
done             # 未引用的$*将会把参数看成单独的单词. 
echo "Arg list seen as separate words."

exit 0