diverse commando's
niet onmiddellijk onder EEn noemer onder te brengen ...
du(directory usage)
man pageNAME du - estimate file space usage SYNOPSIS du [OPTION]... [FILE]... du [OPTION]... --files0-from=F DESCRIPTION Summarize disk usage of the set of FILEs, recursively for directories. Mandatory arguments to long options are mandatory for short options too.
interessante link(s):
https://www.tecmint.com/check-linux-disk-usage-of-files-and-directories/
voorbeelden:
du -chs
grand total (c), human readable (h), summarize (s)
merk het verschil op in gebruik ...
zonder asterisk*$ du -chs /var 2>/dev/null 806M /var 806M total
... met asterisk*$ du -chs /var/* 2>/dev/null 18M /var/backups 455M /var/cache 8,0K /var/games 310M /var/lib 4,0K /var/local 0 /var/lock 12M /var/log 4,0K /var/mail 4,0K /var/opt 0 /var/run 60K /var/spool 12M /var/tmp 4,0K /var/www 806M total
du -cs /etc/* 2>/dev/null | sort -nr
ordent de meest gevulde files en directories bovenaan ...$ du -cs /etc/* 2>/dev/null | sort -nr | head 28932 total 11724 /etc/skel 3672 /etc/brltty 1036 /etc/apparmor.d 1024 /etc/gufw 936 /etc/ssl 704 /etc/mono 652 /etc/apache2 496 /etc/X11 436 /etc/fontsat
man pageNAME at, batch, atq, atrm - queue, examine or delete jobs for later execu‐ tion SYNOPSIS at [-V] [-q queue] [-f file] [-mMlv] timespec... at [-V] [-q queue] [-f file] [-mMkv] [-t time] at -c job [job...] atq [-V] [-q queue] at [-rd] job [job...] atrm [-V] job [job...] batch at -b DESCRIPTION at and batch read commands from standard input or a specified file which are to be executed at a later time, using /bin/sh. at executes commands at a specified time. atq lists the user's pending jobs, unless the user is the supe‐ ruser; in that case, everybody's jobs are listed. The format of the output lines (one for each job) is: Job number, date, hour, queue, and username. atrm deletes jobs, identified by their job number. batch executes commands when system load levels permit; in other words, when the load average drops below 1.5, or the value specified in the invocation of atd.
interessante link(s):
https://www.tecmint.com/linux-cron-alternative-at-command-to-schedule-tasks/
voorbeeld
$ echo "wget https://nl.wordpress.org/wordpress-4.9.4-nl_NL.tar.gz"| at -t 201803021155warning: commands will be executed using /bin/sh job 2 at Fri Mar 2 11:55:00 2018$ atq1 Fri Mar 2 11:55:00 2018 a user 2 Fri Mar 2 11:55:00 2018 a user$ atrm 2
$ atq1 Fri Mar 2 11:55:00 2018 a user
om de output van het ge-schedule-de commando te zien, moeten we in linux onze lokale mail raadplegen.
In mijn geval draaide er geen lokale maildaemon:
Het volgende commando toont alle draaiende daemons ....
$ sudo systemctl list-unit-files | grep enabled | sortaccounts-daemon.service enabled acpid.path enabled acpid.socket enabled anacron-resume.service enabled anacron.service enabled apt-daily.timer enabled apt-daily-upgrade.timer enabled atd.service enabled autovt@.service enabled avahi-daemon.service enabled avahi-daemon.socket enabled bind9.service enabled binfmt-support.service enabled bluetooth.service enabled brltty.service enabled casper.service enabled cgmanager.service enabled cgproxy.service enabled cron.service enabled cups-browsed.service enabled cups.path enabled cups.service enabled cups.socket enabled dbus-org.bluez.service enabled dbus-org.freedesktop.Avahi.service enabled dbus-org.freedesktop.ModemManager1.service enabled dbus-org.freedesktop.nm-dispatcher.service enabled dbus-org.freedesktop.thermald.service enabled display-manager.service enabled dm-event.socket enabled dns-clean.service enabled friendly-recovery.service enabled getty@.service enabled gpu-manager.service enabled hddtemp.service enabled lightdm.service enabled lm-sensors.service enabled lvm2-lvmetad.socket enabled lvm2-lvmpolld.socket enabled lvm2-monitor.service enabled mintsystem.service enabled ModemManager.service enabled munin-node.service enabled mysql.service enabled networking.service enabled NetworkManager-dispatcher.service enabled network-manager.service enabled NetworkManager.service enabled NetworkManager-wait-online.service enabled ntp.service enabled openvpn.service enabled pppd-dns.service enabled remote-fs.target enabled resolvconf.service enabled rsyslog.service enabled sshd.service enabled ssh.service enabled syslog.service enabled systemd-timesyncd.service enabled thermald.service enabled ufw.service enabled ureadahead.service enabled uuidd.socket enabled vboxautostart-service.service enabled vboxballoonctrl-service.service enabled vboxdrv.service enabled vboxweb-service.service enabled vsftpd.service enabled
netstat gaf ook geen open poort 25 ....
$ netstat -vatn | grep 127tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN tcp 0 0 127.0.1.1:53 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN
En daarom moeten we postfix installeren:
$ sudo apt install postfix
netstat geeft vervolgens wel poort 25 ...
$ netstat -vatn | grep :25tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN tcp6 0 0 ::1:25 :::* LISTENen we kunnen dus ons
atexperiment verder zetten ....
$ echo "ping -c 10 -i 0.2 google.be"| at -m -t 201803020934warning: commands will be executed using /bin/sh job 7 at Fri Mar 2 09:34:00 2018$ mails-nail version v14.8.6. Type ? for help. "/var/mail/user": 1 message 1 new >N 1 user Fri Mar 2 09:34 28/1589 Output from your job 7? 1[-- Message 1 -- 28 lines, 1589 bytes --]: From user@lap17.syntraab.mechelen Fri Mar 2 09:34:03 2018 Subject: Output from your job 7 To: bert@lap17.syntraab.mechelen Message-Id: <20180302083403.09C461221C8@lap17.syntraab.mechelen> Date: Fri, 2 Mar 2018 09:34:02 +0100 (CET) From: user@lap17.syntraab.mechelen (bert) PING google.be (172.217.20.67) 56(84) bytes of data. 64 bytes from ams15s33-in-f3.1e100.net (172.217.20.67): icmp_seq=1 ttl=55 time=16.6 ms 64 bytes from ams15s33-in-f3.1e100.net (172.217.20.67): icmp_seq=2 ttl=55 time=10.9 ms 64 bytes from ams15s33-in-f3.1e100.net (172.217.20.67): icmp_seq=3 ttl=55 time=15.5 msals het commando
mailniet werkt moeten we nogmailutilsinstalleren ...
sudo apt install mailutils