我的理解是linux中的所有命令都必须存在于$PATH上,即使对于最基本的命令也是如此。> which cd> which ls但当我尝试which pushd时,令我惊讶的是,它又回来了:
/usr/bin/which: no pushd in (/binusr/share/maven/bin:/usr/share/j
用于man hier的Linux文件系统层次结构文档( /usr/bin )说: This is the primary directory for executable programsMost programs executed by normal users which are not are not installed locally