linux中shell变量$#,$@,$0,$1,$2的含义解释
变量说明:
$$
Shell本身的PID（ProcessID）
$!
Shell最后运行的后台Process的PID
$?
最后运行的命令的结束代码（返回值）
$*
所有参数列表。如"$*"用「"」括起来的情况、以"$1 $2 … $n"的形式输出所有参数。
$@
所有参数列表。如"$@"用「"」括起来的情况、以"$1" "$2" … "$n" 的形式输出所有参数。
$#
添加到Shell的参数个数
$0
Shell本身的文件名
$1～$n
添加到Shell的各参数值。$1是第1参数、$2是第2参数…。
eric@eric-virtual-machine:~$ cat ethdev1/variable.sh printf "The complete list $$ is %s " "$$" printf "********** " printf "The complete list $! is %s " "$!" printf "********** " printf "The complete list $? is %s " "$?" printf "********** " printf "The complete list $* is %s " "$*" printf "********** " printf "The complete list $@ is %s " "$@" printf "********** " printf "The complete list $# is %s " "$#" printf "********** " printf "The complete list $0 is %s " "$0" printf "********** " printf "The complete list $1 is %s " "$1" printf "********** " printf "The complete list $2 is %s " "$2" printf "********** " eric@eric-virtual-machine:~$ ethdev1/variable.sh QQ 809512722 The complete list $$ is 7674 ********** The complete list $! is ********** The complete list $? is 0 ********** The complete list $* is QQ 809512722 ********** The complete list $@ is QQ The complete list $@ is 809512722 ********** The complete list $# is 2 ********** The complete list $0 is ethdev1/variable.sh ********** The complete list $1 is QQ ********** The complete list $2 is 809512722 **********