Commands by jhyland87 (4)

  • Use Growl to monitor your local apache error logs for new messages

    Simply add this to whatever apache startup script you have, or if you are on a MAC, create a new automator application. This will show a pretty growl notification whenever theres a new Apache error log entry. Useful for local development


    0
    /usr/bin/tail -fn0 /path/to/apache_error.log | while read line; do /usr/local/bin/growlnotify --title "Apache Notice" --message "$line"; done &
    jhyland87 · 2013-01-22 05:25:41 5
  • updatedb for MAC OSX

    MAC OSX doesn't come with an updatedb command by default, this will emulate the updatedb thats on a typical Linux OS. Simply add it to your ~/.bash_profile


    2
    alias updatedb="sudo /usr/libexec/locate.updatedb"
    jhyland87 · 2013-01-21 17:46:57 6
  • Locate command for MAC OSX

    MAC OSX doesn't come with a locate command, This will do the same thing as the locate command on a typical Linux OS. Simply add it to your ~/.bash_profile


    0
    alias locate='if [ $((`date +%s`-`eval $(stat -s /var/db/locate.database); echo $st_mtime`)) -gt 3600 ]; then echo "locate: db is too old!">/dev/stderr; sudo /usr/libexec/locate.updatedb; fi; locate -i'
    jhyland87 · 2013-01-21 17:45:50 4
  • Get top N files in X directory

    You can simply run "largest", and list the top 10 files/directories in ./, or you can pass two parameters, the first being the directory, the 2nd being the limit of files to display. Best off putting this in your bashrc or bash_profile file Show Sample Output


    1
    largest() { dir=${1:-"./"}; count=${2:-"10"}; echo "Getting top $count largest files in $dir"; du -sx "$dir/"* | sort -nk 1 | tail -n $count | cut -f2 | xargs -I file du -shx file; }
    jhyland87 · 2013-01-21 09:45:21 7

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Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Redirect STDIN
Several times, I find myself hitting my up arrow, and changing the search term. Unfortunately, I find myself wasting too much time typing: $ grep kernel /var/log/messages Redirecting STDIN allows me to put the search term at the end so I less cursor movement to change what I'm searching for: $ < /var/log/messages grep kernel If you're using the emacs keyboard binding, then after you press your up arrow, press CTRL+w to erase the word. If this has already been submitted, I couldn't find it with the search utility.

Generate Random Passwords
If you want a password length longer than 6, changing the -c6 to read -c8 will give you 8 random characters instead of 6. To end up with a line-feed, use this with echo: # echo `< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c6` Modern systems need higher strenght, so add some special characters: # < /dev/urandom tr -dc '12345!@#$%qwertQWERTasdfgASDFGzxcvbZXCVB' | head -c8

Reset hosed terminal,
stty sane resets the tty to basic usable function. The ^J is a newline -- sometimes CR/LF interpretation is broken so use the ^J explicitly.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Short and sweet output from dig(1)
Turn off almost all of dig's output except for what you'd see in a zone file. This can also be put into ~/.digrc.

watch iptables counters
Watch the number of packets/bytes coming through the firewall. Useful in setting up new iptables rules or chains. Use this output to reorder rules for efficiency.

dd if=/dev/null of=/dev/sda
removes all files/filesystems of a harddisk. It removes EVERYTHING of your hard disk. Be carefull when to select a device. It does not prompt for and second check.

Show an application's environment variables

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