Commands tagged System Administration (11)

  • Run a file system check on your next boot.

    The empty file /forcefsck causes the file system check fsck to be run next time you boot up, after which it will be removed. This works too: sudo >/forcefsck


    38
    sudo touch /forcefsck
    johnraff · 2009-10-29 17:04:47 19
  • List all files opened by a particular command

    List all file opened by a particular command based on it's command name. Show Sample Output


    25
    lsof -c dhcpd
    d4n3sh · 2009-04-17 07:18:38 11
  • List files opened by a PID

    Lis all files opened by a particular process id. "PID" Show Sample Output


    6
    lsof -p 15857
    d4n3sh · 2009-04-17 07:16:03 5
  • Don't spam root. Log your cronjob output to syslog

    This command will log the output of your simple cronjobs to syslog, and syslog will take it from there. Works great for monitoring scripts which only produce simple output. Advantages: * This can be used by regular users, without modifying system files like /etc/syslog.conf * Reduce cron spam to root@localhost (Please stop spaming the sysadmins) * Uses common tools like syslog (and logrotate) so that you don't need to maintain yet another krufty logfile. * Still ensures that the output is logged somewhere, for posterity. Perhaps it's stored the secure, central syslog server, for example. * Seems to work fine on Ubuntu, CentOS, FreeBSD & MacOSX Show Sample Output


    6
    */5 * * * * root /usr/local/nagios/sbin/nsca_check_disk 2>&1 |/usr/bin/logger -t nsca_check_disk
    StefanLasiewski · 2010-07-02 00:47:05 8
  • Listing package man page, services, config files and related rpm of a file, in one alias

    Many times I give the same commands in loop to find informations about a file. I use this as an alias to summarize that informations in a single command. Now with variables! :D Show Sample Output


    2
    fileinfo() { RPMQF=$(rpm -qf $1); RPMQL=$(rpm -ql $RPMQF);echo "man page:";whatis $(basename $1); echo "Services:"; echo -e "$RPMQL\n"|grep -P "\.service";echo "Config files:";rpm -qc $RPMQF;echo "Provided by:" $RPMQF; }
    nnsense · 2015-05-11 16:46:01 13
  • turn off auto hard disc boot scanning for ext3


    1
    tune2fs -c -1 -i 0 /dev/VG0/data
    christian773 · 2010-05-29 08:20:35 4
  • create random numbers within range for conjob usage

    if you need to install cron jobs in a given time range. Show Sample Output


    1
    H=$(until ([ $i -le 6 -a $i -gt 0 -o $i -le 23 -a $i -gt 21 ] ); do i=$(date +%N | cut -c8-10); done ; echo $i) ; M=$(until [ $i -le 59 ]; do i=$(date +%N | cut -c8-10); done ; echo $i) ; echo $M $H \* \* \* backup-rsync-push.sh
    christian773 · 2010-05-29 08:42:43 7
  • Which .service related this file?

    I use this as an alias to get all .service files related a single installed file/conf (if it has services, of course). For rpm based systems ;) Show Sample Output


    1
    qf2s() { rpm -ql $(rpm -qf $1)|grep -P "\.service"; }
    nnsense · 2015-05-11 16:32:16 9
  • Manage "legacy" service run control links

    Change run control links from start "S" to stop "K" (kill) for whatever run levels in curly braces for a service called "myservice". NEWFN variable is for the new filename stored in the in-line shell. Use different list of run levels (rc*.d, rc{1,3,5}.d, etc.) and/or swap S with K in the command to change function of run control links. Show Sample Output


    0
    sudo find /etc/rc{1..5}.d -name S99myservice -type l -exec sh -c 'NEWFN=`echo {} | sed 's/S99/K99/'` ; mv -v {} $NEWFN' \;
    zoomgarden · 2010-01-03 00:56:57 5
  • manually set system date/time

    date MMDDhhmmYYYY date MMDDhhmm # example 27.12.1975 08:00 date 122708001975 Show Sample Output


    -1
    date MMDDhhmmYYYY
    christian773 · 2010-05-29 08:26:13 4
  • show system installation date


    -3
    tune2fs -l $(df -P / | tail -n1 | cut -d' ' -f1 ) | grep 'Filesystem created:'
    christian773 · 2010-05-29 08:15:25 5

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List your installed Firefox extensions

Find C/C++ source files
Find C/C++ source files and headers in the current directory.

list files recursively by size

View ~/.ssh/known_hosts key information
Will return the SSH server key information for each host you have in your ~/.ssh/known_hosts file, including key size, key fingerprint, key IP address or domain name, and key type.

List out classes in of all htmls in directory
Lists out all classes used in all *.html files in the currect directory. usefull for checking if you have left out any style definitions, or accidentally given a different name than you intended. ( I have an ugly habit of accidentally substituting camelCase instead of using under_scores: i would name soemthing counterBox instead of counter_box) WARNING: assumes you give classnames in between double quotes, and that you apply only one class per element.

Automator Bash script to create Clean zips in MacOS Finder without __MACOSX metadata
Finder compresses to ZIP but always includes extraneous metadata files (__MACOSX and .DS_Store) files and folders that may confuse other programs. One alternative is creating them and then editing the ZIP. This can work standalone or in an automator script accepting multiple selections (files or folders) and creating one zip per argument/selected file without that metada.

convert single digit to double digits
Uses 'rename' to pad zeros in front of first existing number in each filename. The "--" is not required, but it will prevent errors on filenames which start with "-". You can change the "2d" to any number you want, equaling the total numeric output: aka, 4d = ????, 8d = ????????, etc. I setup a handful of handy functions to this effect (because I couldn't figure out how to insert a var for the value) in the form of 'padnum?', such as: padnum5 () { /usr/bin/rename 's/\d+/sprintf("%05d",$&)/e' -- $@ } Which would change a file "foo-1.txt" to "foo-00001.txt"

fast access to any of your favorite directory.
example: -------------------------------------------------------------------------------------------- user@ubuntu:~/workspace/SVN/haystak-repos/trunk/internal/src$ addpi -------------------------------------------------------------------------------------------- Now that directory is in the list of fast access directories. You can switch to it anytime like this: -------------------------------------------------------------------------------------------- user@ubuntu:~$ pi internal` user@ubuntu:~/workspace/SVN/haystak-repos/trunk/internal/src$ -------------------------------------------------------------------------------------------- Please note the backquote ( the symbol that shares its key with ~ in the keyboard ) pi will switch you to that directory. To see the list of all fast access directories you have to say "cat ~/.pi"

List recorded formular fields of Firefox
When you fill a formular with Firefox, you see things you entered in previous formulars with same field names. This command list everything Firefox has registered. Using a "delete from", you can remove anoying Google queries, for example ;-)

Generate diff of first 500 lines of two files
Useful for massive files where doing a full diff would take too long. This just runs diff on the first 500 lines of each. The use of subshells to feed STDIN is quite a useful construct.

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