Commands by px (3)

  • 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
  • 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 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


    10
    screen /dev/tty<device> 9600
    px · 2010-07-20 09:12:13 3

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Picture Renamer
jhead is a very nice tool to do all sorts of things with photographs, in a batch-oriented way. It has a specific function to rename files based on dates, and the format I used above was just an example.

Reload all sysctl variables without reboot
Use `sysctl -p` without argument will only load /etc/sysctl.conf, but user configs always put in /etc/sysctl.d/*.conf, `sysctl --system` will load all the config files

Find usb device
I often use it to find recently added ou removed device, or using find in /dev, or anything similar. Just run the command, plug the device, and wait to see him and only him

replace recursive in folder with sed

Search for a process by name
ps and grep is a dangerous combination -- grep tries to match everything on each line (thus the all too common: grep -v grep hack). ps -C doesn't use grep, it uses the process table for an exact match. Thus, you'll get an accurate list with: ps -fC sh rather finding every process with sh somewhere on the line.

Display condensed log in a tree-like format.
Display condensed log in a tree-like format.

Rename files in batch

launch bash without using any letters
I don't know why anyone would use this, I was just messing around tonight and managed to start bash without using any letters and thought I would share. It's pretty simple, first it tries to execute "-" redirecting stderr to stdout which prints the error "bash: -: command not found" to standard output, then I try to execute "bash: -: command not found" which produces the output "bash: bash: -: command not found: command not found". lastly, (on the other side of the semicolon) I use the underscore environment variable which refers to the last command run ("bash: -: command not found") and take out everything after the first ":" character using brace expressions and your left with "bash"

Twitter update from terminal (pok3's snipts ?)
Found it on snipt, pok3, is it yours? I put my user = m33600, the password and the status was my robot message: Settima robot message: ALARM ZONE 3 (sent via command line). Now bots may have their identity on twitter...

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"


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