bash脚本中$ @和$ *之间的区别 [英] difference between $@ and $* in bash script

问题描述

下面有4个bash片段.我用./script.sh a b c

There are 4 bash snippets below. I call them with ./script.sh a b c

for arg in $@; do 
echo "$arg"
done   ## output "a\nb\nc"

for arg in "$@"; do
echo "$arg"
done  ## output "a\nb\nc" -- I don't know why

for arg in $*; do
echo "$arg"
done  ##    output "a\nb\nc"

for arg in "$*"; do
echo "$arg"
done    ## output "abc"

我不知道$@和$*之间的确切区别是什么，
而且我认为"$@"和"$*"应该相同，但事实并非如此.为什么?

I don't know what is the exact difference between $@ and $*,
and I think "$@" and "$*" should be the same, but they are not. Why?

推荐答案

如果您有脚本foo.sh:

asterisk "$*"
at-sign "$@"

并调用:

./foo.sh "a a" "b b" "c c"

等效于:

asterisk "a a b b c c"
at-sign "a a" "b b" "c c"

---

没有引号，它们是相同的:

---

Without the quotes, they're the same:

asterisk $*
at-sign $@

将等同于:

asterisk "a" "a" "b" "b" "c" "c"
at-sign "a" "a" "b" "b" "c" "c"

这篇关于bash脚本中$ @和$ *之间的区别的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！