Linux中,command命令是一个用于确定给定命令的类型和位置的实用程序。具体来说,它可以检查指定命令是内建命令、外部命令还是别名。 主要功能 查找命令的类型:command命令可以确定某个命令是否为 Shell 内建命令。 执行命令:使用command运行命令时,可以忽略任何 Shell 函数的定义,仅执行程序或者内建命令。 查找命令的路径...
To change permissions, use the chmod command. First, pick the set of permissions that you want to change, and then pick the bit to change. For example, to add group (g) and world (o, for “other”) read (r) permissions to file, you could run these two commands: ...
The parentheses, when grouped around a command,cause the command to be executed in a subshell. Any environmental changes occuring within the subshell do not persist beyond its execution; in other words,all changes to the working environment of the commands issued within the parentheses do not affe...
command [-pVv] command [arg ...] DESCRIPTION Execute a simple command or display information about commands. Runs COMMAND with ARGS suppressing shell function lookup, or display information about the specified COMMANDs. Can be used to invoke commands on disk when a function with the same name e...
sudo[-b][-p prompt][-u username/#uid]-s sudo command 参数说明: -V 显示版本编号 -h 会显示版本编号及指令的使用方式说明 -l 显示出自己(执行 sudo 的使用者)的权限 -v 因为 sudo 在第一次执行时或是在 N 分钟内没有执行(N 预设为五)会问密码,这个参数是重新做一次确认,如果超过 N 分钟,也会...
at - Schedules commands to be executed at a later time. atd - Runs jobs that are queued by at. atq - Shows any queued at jobs for the current user or for a specified user. atrm - Removes jobs from the at or batch queues. atrun - Runs jobs that are queued by the at command to...
source /path/to/config_file ./path/to/config_file 如果别名同原命令同名,如果要执行原命令,可使用 \ALIASNAME “ALIASNAME” ‘ALIASNAME’ commandALIASNAME /path/command//只适用于外部命令 别名是临时的,hash缓存的是外部命令 4、命令格式 COMMAND[OPTIONS…][ARGUMENTS…] ...
This chapter is a guide to the Unix commands and utilities that will be referenced throughout this book. This is preliminary material, and you may ...
Linux commands share a simple, common structure. This section describes their common structure and explains how you can obtain helpful information about the commands available to you. Commands and Arguments The general form of a shell command line is this: ...
# Append commands to the history file as soon as they are executed. # This is set by default for interactive shells, but not for shell scripts. shopt -s histappend # Save command history export HISTSIZE=10000 export HISTFILESIZE=10000 ...