无法让expand_aliases生效

发布时间：2020-12-16 01:25:18 所属栏目：安全来源：网络整理

导读：我不能让expand_aliases在bash中生效.我尝试了很多不同的事情,没有任何作用. 这是简单的测试用例： /bin/bash -c 'shopt -s expand_aliases; alias cdtmp="cd /tmp"; alias; cdtmp; pwd;' 并输出： $/bin/bash -c 'shopt -s expand_aliases; alias cdtmp="cd

我不能让expand_aliases在bash中生效.我尝试了很多不同的事情,没有任何作用.

这是简单的测试用例：

/bin/bash -c 'shopt -s expand_aliases; alias cdtmp="cd /tmp"; alias; cdtmp; pwd;'

并输出：

$/bin/bash -c 'shopt -s expand_aliases; alias cdtmp="cd /tmp"; alias; cdtmp; pwd;'
alias cdtmp='cd /tmp'
/bin/bash: cdtmp: command not found
/home/user

$/bin/bash --version
GNU bash,version 3.2.25(1)-release (i686-redhat-linux-gnu)
Copyright (C) 2005 Free Software Foundation,Inc.

(是的,我正在使用shopt而不是-O选项来bash,只是为了证明它已经完成了.)

有任何想法吗？

别名不可用于同一行或相同功能的定义.

从Bash手册页：

       The rules concerning the definition and use  of  aliases  are  somewhat
       confusing.   Bash  always  reads  at  least  one complete line of input
       before executing any  of  the  commands  on  that  line.   Aliases  are
       expanded  when  a command is read,not when it is executed.  Therefore,an alias definition appearing on the same line as another command  does
       not  take  effect  until  the next line of input is read.  The commands
       following the alias definition on that line are not affected by the new
       alias.   This  behavior  is  also an issue when functions are executed.
       Aliases are expanded when a function definition is read,not  when  the
       function  is  executed,because a function definition is itself a com                        （编辑：李大同）
【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!