Commands by px (3)

  • easily strace all your apache processes

    This one-liner will use strace to attach to all of the currently running apache processes output and piped from the initial "ps auxw" command into some awk. Show Sample Output


    7
    ps auxw | grep sbin/apache | awk '{print"-p " $2}' | xargs strace
    px · 2011-03-14 21:45:22 7
  • Easy to extend one-liner for cron scripts that automate filesystem checking

    This one-liner is for cron jobs that need to provide some basic information about a filesystem and the time it takes to complete the operation. You can swap out the di command for df or du if that's your thing. The |& redirections the stderr and stdout to the mail command. How to configure the variables. TOFSCK=/path/to/mount FSCKDEV=/dev/path/device or FSCKDEV=`grep $TOFSCK /proc/mounts | cut -f1 -d" "` MAILSUB="weekly file system check $TOFSCK " Show Sample Output


    1
    ( di $TOFSCK -h ; /bin/umount $TOFSCK ; time /sbin/e2fsck -y -f -v $FSCKDEV ; /bin/mount $TOFSCK ) |& /bin/mail $MAILTO -s "$MAILSUB"
    px · 2010-10-24 00:35:23 1
  • use screen as a terminal emulator to connect to serial consoles

    Use GNU/screen as a terminal emulator for anything serial console related. screen /dev/tty eg. screen /dev/ttyS0 9600 MacOSX: http://www.macosxhints.com/article.php?story=20061109133825654 Cheat Sheet: http://www.catonmat.net/blog/screen-terminal-emulator-cheat-sheet/ Show Sample Output


    11
    screen /dev/tty<device> 9600
    px · 2010-07-20 09:12:13 1

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matrix in your term
-a : Asynchronous scroll -b : Bold characters on -x : X window mode, use if your xterm is using mtx.pcf

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" }

draw matrix using dot

Calculate days on which Friday the 13th occurs (inspired from the work of the user justsomeguy)
Friday is the 5th day of the week, monday is the 1st. Output may be affected by locale.

get rid of lines with non ascii characters
found here: https://stackoverflow.com/a/9035939

type fortune in real time

Selecting a random file/folder of a folder
Also looks in subfolders

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Ensure that each machine that you log in to has its own history file
On systems where your home directory is shared across different machines, your bash history will be global, rather than being a separate history per machine. This setting in your .bashrc file will ensure that each machine has its own history file.

Create a 100MB file for testing transfer speed

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