发布时间：2014-12-17 11:34:20

1. which命令的意义（20141212）which用于在环境变量(PATH)中搜索可执行文件(x permission)并返回第一个匹配结果，为什么要这样设定呢？这是因为which命令的设定与Linux系统在执行命令时的步骤“正好”相吻合，因此，就可以使用which搜索所有Linux的可执行命令（Bash内置的命令是which搜索不到的）结论：只要which能搜到.........【阅读全文】

发布时间：2014-12-12 17:40:43

which - show the full path of (shell) commandswhich命令用于在PATH中搜索可执行文件，并返回第一个匹配结果which命令不能查找BASH的内置命令，但可以查找除此之外的所有Shell命令......【阅读全文】

发布时间：2014-11-04 16:35:51

FHS - filesystem hierarchy standardcategoryshareabel - public directoryunshareable - private directorystatic - few be changedvariable - often be changedhierarchy/:     /dev - device documents    /etc - configuration files   &nbs.........【阅读全文】

发布时间：2014-10-30 17:32:21

all of variables are global except those be specified with "local" keyworddeclare equals to typeset ?declare -r : read-onlydeclare -i :  integerdeclare -a : indexed arraydeclare -A : associative arrayfor data_time in {00..23}:{00..59}:00unset 删除指定的shell变量和函数.........【阅读全文】

发布时间：2014-10-26 19:14:48

1. atdepend on atd service, can execute task only oncethe command will be auto create task file in /var/spool/at directory, the command permission relies on /etc/at.allow and /etc/at.deny files, at.allow will overlap at.deny file when configuration crashedat -l : equals to atq command, can q.........【阅读全文】