每天一个Linux命令（43）at命令
Posted MenAngel
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at命令用于在指定时间执行命令。at允许使用一套相当复杂的指定时间的方法。可以用相对时间法指定，也可以用绝对时间法指定。
(1)用法:
用法: at [选项参数] [时间]
(2)功能:
功能: 在指定的时间执行命令。
(3)选项参数:
1) -c 显示即将执行任务的细节
2) -d 用任务id号删除指定的任务
3) -l 等同于atq，用job的id号显示指定的未删除而待执行的任务
(4)实例:
1)[[email protected] sunjimeng]# at now + 1 minutes 用相对时间，在一分钟之后执行命令
[[email protected] sunjimeng]# at now + 2 minutes
at> echo "I‘m MenAngel!,I‘m study at order!"
at> <EOT>
job 11 at Wed Jun 8 17:46:00 2016
at> <EOT>
<这里输入 [ctrl] + d 就会出现 <EOF> 的字样代表结束!
当你输入下一个命令时，系统会自动提醒你，您在 /var/spool/mail/sunjimeng 中有邮件。此邮件中就包含这个命令执行的结果。
2)[[email protected] sunjimeng]# at 17:47 在一个绝对时间执行一个命令
[[email protected] sunjimeng]# at 17:47 at> ls -l /home/sunjimeng/Documents at> <EOT> job 13 at Wed Jun 8 17:47:00 2016 您在 /var/spool/mail/sunjimeng 中有新邮件
这里在语句的末尾提醒你有新邮件，可以用cat命令查看文件:/var/spool/mail/sunjimeng。
3)[[email protected] sunjimeng]# atq 计划任务设定后，在没有执行之前我们可以用atq命令来查看系统没有执行工作任务
[[email protected] sunjimeng]# atq 1 Wed Jun 8 17:21:00 2016 a root 2 Wed Jun 8 17:23:00 2016 a root 3 Wed Jun 8 17:23:00 2016 a root 4 Wed Jun 8 17:26:00 2016 a root 5 Sat Jun 11 17:00:00 2016 a root 6 Wed Jun 8 17:31:00 2016 a root
4)[[email protected] sunjimeng]# atq 删除已经设置的任务
[[email protected] sunjimeng]# atq 1 Wed Jun 8 17:21:00 2016 a root 2 Wed Jun 8 17:23:00 2016 a root 3 Wed Jun 8 17:23:00 2016 a root 4 Wed Jun 8 17:26:00 2016 a root 5 Sat Jun 11 17:00:00 2016 a root 6 Wed Jun 8 17:31:00 2016 a root [[email protected] sunjimeng]# atrm 1 2 3 4 5 [[email protected] sunjimeng]# atq 6 Wed Jun 8 17:31:00 2016 a root
5)[[email protected] sunjimeng]# cat /var/spool/mail/sunjimeng 显示at命令的执行结果
[[email protected] sunjimeng]# cat /var/spool/mail/sunjimeng From [email protected] Wed Jun 8 17:46:01 2016 Return-Path: <[email protected]> X-Original-To: sunjimeng Delivered-To: [email protected] Received: by localhost.localdomain (Postfix, from userid 0) id 24622632F338; Wed, 8 Jun 2016 17:46:01 -0700 (PDT) Subject: Output from your job 11 To: [email protected] Message-Id: <20160609004601[email protected]> Date: Wed, 8 Jun 2016 17:46:01 -0700 (PDT) From: [email protected] (root) I‘m MenAngel!,I‘m study at order! From [email protected] Wed Jun 8 17:47:00 2016 Return-Path: <[email protected]> X-Original-To: sunjimeng Delivered-To: [email protected] Received: by localhost.localdomain (Postfix, from userid 0) id C83A5632F338; Wed, 8 Jun 2016 17:47:00 -0700 (PDT) Subject: Output from your job 13 To: [email protected] Message-Id: <20160609004700[email protected]> Date: Wed, 8 Jun 2016 17:47:00 -0700 (PDT) From: [email protected] (root) 总用量 0 drwxr-xr-x. 2 root root 72 5月 31 18:25 grepDir -rw-r--r--. 1 root root 0 6月 7 23:34 myfile drwxr-xr-x. 2 root root 6 6月 7 23:33 newWatch From [email protected] Wed Jun 8 17:47:00 2016 Return-Path: <[email protected]> X-Original-To: sunjimeng Delivered-To: [email protected] Received: by localhost.localdomain (Postfix, from userid 0) id C9EA3632F33A; Wed, 8 Jun 2016 17:47:00 -0700 (PDT) Subject: Output from your job 12 To: [email protected] Message-Id: <20160609004700[email protected]> Date: Wed, 8 Jun 2016 17:47:00 -0700 (PDT) From: [email protected] (root) 总用量 0 drwxr-xr-x. 2 root root 72 5月 31 18:25 grepDir -rw-r--r--. 1 root root 0 6月 7 23:34 myfile drwxr-xr-x. 2 root root 6 6月 7 23:33 newWatch From [email protected] Wed Jun 8 17:52:01 2016 Return-Path: <[email protected]> X-Original-To: sunjimeng Delivered-To: [email protected] Received: by localhost.localdomain (Postfix, from userid 0) id F3239632F338; Wed, 8 Jun 2016 17:52:00 -0700 (PDT) Subject: Output from your job 14 To: [email protected] Message-Id: <20160609005200[email protected]> Date: Wed, 8 Jun 2016 17:52:00 -0700 (PDT) From: [email protected] (root) I‘m MenAngel From [email protected] Wed Jun 8 17:54:00 2016 Return-Path: <[email protected]> X-Original-To: sunjimeng Delivered-To: [email protected] Received: by localhost.localdomain (Postfix, from userid 0) id 4B264632F338; Wed, 8 Jun 2016 17:54:00 -0700 (PDT) Subject: Output from your job 15 To: [email protected] Message-Id: <20160609005400[email protected]> Date: Wed, 8 Jun 2016 17:54:00 -0700 (PDT) From: [email protected] (root) 总用量 4 drwxr-xr-x. 2 sunjimeng sunjimeng 6 5月 1 01:23 Desktop drwxrwxr-x. 4 sunjimeng users 4096 5月 28 00:24 Document drwxr-xr-x. 4 root sunjimeng 48 6月 7 23:34 Documents drwxr-xr-x. 2 sunjimeng sunjimeng 6 5月 1 01:23 Downloads drwxrwxr-x. 2 sunjimeng sunjimeng 6 5月 17 04:55 findTextDir drwxr-xr-x. 2 sunjimeng sunjimeng 6 5月 1 01:23 Music drwxr-xr-x. 2 sunjimeng sunjimeng 6 5月 1 01:23 Pictures drwxr-xr-x. 2 sunjimeng sunjimeng 6 5月 1 01:23 Public drwxr-xr-x. 2 sunjimeng sunjimeng 6 5月 1 01:23 Templates drwxr-xr-x. 2 sunjimeng sunjimeng 6 5月 1 01:23 Videos From [email protected] Wed Jun 8 17:54:00 2016 Return-Path: <[email protected]> X-Original-To: sunjimeng Delivered-To: [email protected] Received: by localhost.localdomain (Postfix, from userid 0) id 4E5D2632F33A; Wed, 8 Jun 2016 17:54:00 -0700 (PDT) Subject: Output from your job 16 To: [email protected] Message-Id: <20160609005400[email protected]> Date: Wed, 8 Jun 2016 17:54:00 -0700 (PDT) From: [email protected] (root) 总用量 0 drwxr-xr-x. 2 root root 72 5月 31 18:25 grepDir -rw-r--r--. 1 root root 0 6月 7 23:34 myfile drwxr-xr-x. 2 root root 6 6月 7 23:33 newWatch
6)[[email protected] ~]$ at -c 18 根据id号查看即将要执行命令的细节
[[email protected] ~]$ atq //显示结果表明没有即将要执行的任务 [[email protected] ~]$ at now + 1 minutes //新建一个要执行的任务 at> ls -l at> <EOT> job 18 at Wed Jun 8 18:09:00 2016 [[email protected] ~]$ atq //查看 18 Wed Jun 8 18:09:00 2016 a sunjimeng [[email protected] ~]$ at -c 18 //根据id号查看，它的即将执行的细节 #!/bin/sh # atrun uid=1000 gid=1000 # mail sunjimeng 0 umask 2 XDG_VTNR=1; export XDG_VTNR SSH_AGENT_PID=3132; export SSH_AGENT_PID XDG_SESSION_ID=2; export XDG_SESSION_ID HOSTNAME=localhost.localdomain; export HOSTNAME IMSETTINGS_INTEGRATE_DESKTOP=yes; export IMSETTINGS_INTEGRATE_DESKTOP GPG_AGENT_INFO=/run/user/1000/keyring-CchymL/gpg:0:1; export GPG_AGENT_INFO VTE_VERSION=3406; export VTE_VERSION SHELL=/bin/bash; export SHELL XDG_MENU_PREFIX=gnome-; export XDG_MENU_PREFIX HISTSIZE=1000; export HISTSIZE GJS_DEBUG_OUTPUT=stderr; export GJS_DEBUG_OUTPUT WINDOWID=25197065; export WINDOWID GNOME_KEYRING_CONTROL=/run/user/1000/keyring-CchymL; export GNOME_KEYRING_CONTROL GJS_DEBUG_TOPICS=JS\ ERROR\;JS\ LOG; export GJS_DEBUG_TOPICS IMSETTINGS_MODULE=IBus; export IMSETTINGS_MODULE USER=sunjimeng; export USER LS_COLORS=rs=0:di=38\;5\;27:ln=38\;5\;51:mh=44\;38\;5\;15:pi=40\;38\;5\;11:so=38\;5\;13:do=38\;5\;5:bd=48\;5\;232\;38\;5\;11:cd=48\;5\;232\;38\;5\;3:or=48\;5\;232\;38\;5\;9:mi=05\;48\;5\;232\;38\;5\;15:su=48\;5\;196\;38\;5\;15:sg=48\;5\;11\;38\;5\;16:ca=48\;5\;196\;38\;5\;226:tw=48\;5\;10\;38\;5\;16:ow=48\;5\;10\;38\;5\;21:st=48\;5\;21\;38\;5\;15:ex=38\;5\;34:\*.tar=38\;5\;9:\*.tgz=38\;5\;9:\*.arc=38\;5\;9:\*.arj=38\;5\;9:\*.taz=38\;5\;9:\*.lha=38\;5\;9:\*.lz4=38\;5\;9:\*.lzh=38\;5\;9:\*.lzma=38\;5\;9:\*.tlz=38\;5\;9:\*.txz=38\;5\;9:\*.tzo=38\;5\;9:\*.t7z=38\;5\;9:\*.zip=38\;5\;9:\*.z=38\;5\;9:\*.Z=38\;5\;9:\*.dz=38\;5\;9:\*.gz=38\;5\;9:\*.lrz=38\;5\;9:\*.lz=38\;5\;9:\*.lzo=38\;5\;9:\*.xz=38\;5\;9:\*.bz2=38\;5\;9:\*.bz=38\;5\;9:\*.tbz=38\;5\;9:\*.tbz2=38\;5\;9:\*.tz=38\;5\;9:\*.deb=38\;5\;9:\*.rpm=38\;5\;9:\*.jar=38\;5\;9:\*.war=38\;5\;9:\*.ear=38\;5\;9:\*.sar=38\;5\;9:\*.rar=38\;5\;9:\*.alz=38\;5\;9:\*.ace=38\;5\;9:\*.zoo=38\;5\;9:\*.cpio=38\;5\;9:\*.7z=38\;5\;9:\*.rz=38\;5\;9:\*.cab=38\;5\;9:\*.jpg=38\;5\;13:\*.jpeg=38\;5\;13:\*.gif=38\;5\;13:\*.bmp=38\;5\;13:\*.pbm=38\;5\;13:\*.pgm=38\;5\;13:\*.ppm=38\;5\;13:\*.tga=38\;5\;13:\*.xbm=38\;5\;13:\*.xpm=38\;5\;13:\*.tif=38\;5\;13:\*.tiff=38\;5\;13:\*.png=38\;5\;13:\*.svg=38\;5\;13:\*.svgz=38\;5\;13:\*.mng=38\;5\;13:\*.pcx=38\;5\;13:\*.mov=38\;5\;13:\*.mpg=38\;5\;13:\*.mpeg=38\;5\;13:\*.m2v=38\;5\;13:\*.mkv=38\;5\;13:\*.webm=38\;5\;13:\*.ogm=38\;5\;13:\*.mp4=38\;5\;13:\*.m4v=38\;5\;13:\*.mp4v=38\;5\;13:\*.vob=38\;5\;13:\*.qt=38\;5\;13:\*.nuv=38\;5\;13:\*.wmv=38\;5\;13:\*.asf=38\;5\;13:\*.rm=38\;5\;13:\*.rmvb=38\;5\;13:\*.flc=38\;5\;13:\*.avi=38\;5\;13:\*.fli=38\;5\;13:\*.flv=38\;5\;13:\*.gl=38\;5\;13:\*.dl=38\;5\;13:\*.xcf=38\;5\;13:\*.xwd=38\;5\;13:\*.yuv=38\;5\;13:\*.cgm=38\;5\;13:\*.emf=38\;5\;13:\*.axv=38\;5\;13:\*.anx=38\;5\;13:\*.ogv=38\;5\;13:\*.ogx=38\;5\;13:\*.aac=38\;5\;45:\*.au=38\;5\;45:\*.flac=38\;5\;45:\*.mid=38\;5\;45:\*.midi=38\;5\;45:\*.mka=38\;5\;45:\*.mp3=38\;5\;45:\*.mpc=38\;5\;45:\*.ogg=38\;5\;45:\*.ra=38\;5\;45:\*.wav=38\;5\;45:\*.axa=38\;5\;45:\*.oga=38\;5\;45:\*.spx=38\;5\;45:\*.xspf=38\;5\;45:; export LS_COLORS SSH_AUTH_SOCK=/run/user/1000/keyring-CchymL/ssh; export SSH_AUTH_SOCK SESSION_MANAGER=local/unix:@/tmp/.ICE-unix/2990,unix/unix:/tmp/.ICE-unix/2990; export SESSION_MANAGER USERNAME=sunjimeng; export USERNAME GNOME_SHELL_SESSION_MODE=classic; export GNOME_SHELL_SESSION_MODE PATH=/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:/home/sunjimeng/.local/bin:/home/sunjimeng/bin; export PATH MAIL=/var/spool/mail/sunjimeng; export MAIL DESKTOP_SESSION=gnome-classic; export DESKTOP_SESSION QT_IM_MODULE=ibus; export QT_IM_MODULE PWD=/home/sunjimeng; export PWD XMODIFIERS[email protected]=ibus; export XMODIFIERS GNOME_KEYRING_PID=2967; export GNOME_KEYRING_PID LANG=zh_CN.utf8; export LANG GDM_LANG=zh_CN.utf8; export GDM_LANG GDMSESSION=gnome-classic; export GDMSESSION HISTCONTROL=ignoredups; export HISTCONTROL XDG_SEAT=seat0; export XDG_SEAT HOME=/home/sunjimeng; export HOME SHLVL=2; export SHLVL GNOME_DESKTOP_SESSION_ID=this-is-deprecated; export GNOME_DESKTOP_SESSION_ID LOGNAME=sunjimeng; export LOGNAME DBUS_SESSION_BUS_ADDRESS=unix:abstract=/tmp/dbus-O0naLUCbYg,guid=ad8d9a1bab9eccd8c11d0a6257493a83; export DBUS_SESSION_BUS_ADDRESS LESSOPEN=\|\|/usr/bin/lesspipe.sh\ %s; export LESSOPEN WINDOWPATH=1; export WINDOWPATH XDG_RUNTIME_DIR=/run/user/1000; export XDG_RUNTIME_DIR COLORTERM=gnome-terminal; export COLORTERM XAUTHORITY=/run/gdm/auth-for-sunjimeng-Bcg9Bg/database; export XAUTHORITY cd /home/sunjimeng || { echo ‘Execution directory inaccessible‘ >&2 exit 1 } ${SHELL:-/bin/sh} << ‘marcinDELIMITER7e20521d‘ ls -l marcinDELIMITER7e20521d [[email protected] ~]$
7)[[email protected] ~]$ at -d 21 取消指向执行id号为21的任务
[[email protected] ~]$ atq 20 Wed Jun 8 18:15:00 2016 a sunjimeng 21 Wed Jun 8 18:16:00 2016 a sunjimeng [[email protected] ~]$ atrm 20 [[email protected] ~]$ atq 21 Wed Jun 8 18:16:00 2016 a sunjimeng [[email protected] ~]$ at -d 21 [[email protected] ~]$ atq
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