Linux下which、whereis、locate、find命令的区别

• which

which是通过 PATH环境变量 到该路径内查找可执行文件

• whereis

whereis.c的源码，在缺省的情况下，会找当前和以下的路径 static char *bindirs[] = { "/bin", "/usr/bin", "/sbin", "/usr/sbin", "/etc", "/usr/etc", "/lib", "/usr/lib", "/lib64", "/usr/lib64", "/usr/games", "/usr/games/bin", "/usr/games/lib", "/usr/emacs/etc", "/usr/lib/emacs/*/etc", "/usr/TeX/bin", "/usr/tex/bin", "/usr/interviews/bin/LINUX", "/usr/X11R6/bin", "/usr/X386/bin", "/usr/bin/X11", "/usr/X11/bin", "/usr/X11R5/bin", "/usr/local/bin", "/usr/local/sbin", "/usr/local/etc", "/usr/local/lib", "/usr/local/games", "/usr/local/games/bin", "/usr/local/emacs/etc", "/usr/local/TeX/bin", "/usr/local/tex/bin", "/usr/local/bin/X11", "/usr/contrib", "/usr/hosts", "/usr/include", "/usr/g++-include", "/usr/ucb", "/usr/old", "/usr/new", "/usr/local", "/usr/libexec", "/usr/share", "/opt/*/bin", 0 }; static char *mandirs[] = { "/usr/man/*", "/usr/share/man/*", "/usr/X386/man/*", "/usr/X11/man/*", "/usr/TeX/man/*", "/usr/interviews/man/mann", 0 }; static char *srcdirs[]  = { "/usr/src/*", "/usr/src/lib/libc/*", "/usr/src/lib/libc/net/*", "/usr/src/ucb/pascal", "/usr/src/ucb/pascal/utilities", "/usr/src/undoc", 0 };

• locate

使用自己的一个数据库，使用updatedb来更新文件系统，会有时效性问题。

• find

搜寻实时硬盘文件名称 (find也可以根据文件大小-size 时间-atime 正则表达式-regex)