Commands by shavenwarthog

Commands by shavenwarthog (3)

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easily trace all Nginx processes

Nginx (and other webservers like Apache) can be awkward to trace. They run as root, then switch to another user once they're ready to serve web pages. They also have a "master" process and multiple worker processes. The given command finds the process IDs of all Nginx processes, joins them together with a comma, then traces all of them at once with "sudo strace." System trace output can be overwhelming, so we only capture "networking" output. TIP: to kill this complex strace, do "sudo killall strace". Compare with a similar command: http://www.commandlinefu.com/commands/view/11918/easily-strace-all-your-apache-processes Show Sample Output
This is sample output - yours may be different.
```
# grab an Nginx web page:
#     curl -so /dev/null localhost

[pid  1145] accept4(6, {sa_family=AF_INET, sin_port=htons(57358), sin_addr=inet_addr("127.0.0.1")}, [16], SOCK_NONBLOCK) = 10
[pid  1145] recvfrom(10, "GET / HTTP/1.1\r\nUser-Agent: curl"..., 1024, 0, NULL, NULL) = 73
[pid  1145] setsockopt(10, SOL_TCP, TCP_CORK, [1], 4) = 0
[pid  1145] sendfile(10, 11, [0], 612)  = 612
[pid  1145] setsockopt(10, SOL_TCP, TCP_CORK, [0], 4) = 0
[pid  1145] recvfrom(10, 0xa7e1c0, 1024, 0, 0, 0) = -1 EAGAIN (Resource temporarily unavailable)
[pid  1145] recvfrom(10, "", 1024, 0, NULL, NULL) = 0
```
0

sudo strace -e trace=network -p `pidof nginx | sed -e 's/ /,/g'`

shavenwarthog · 2016-01-28 18:48:16 12
sudo for launching gui apps in background

"The -b (background) option tells sudo to run the given command in the background." -- after it asks you for the password in the foreground. Show Sample Output
This is sample output - yours may be different.
```
#
```
0

sudo -b xterm

shavenwarthog · 2010-10-05 23:03:01 5
set desktop background to highest-rated image from Reddit /r/wallpapers

You'll need "feh" to set the background from the commandline. Install with "apt-get install feh" Thanks to the Redditors on this thread: http://www.reddit.com/r/linux/comments/bira4/is_there_a_linux_version_of_this_preferably_a/
This is sample output - yours may be different.
4

curl http://www.reddit.com/r/wallpapers.rss | grep -Eo 'http:[^&]+jpg' | head -1 | xargs feh --bg-seamless

shavenwarthog · 2010-03-27 00:08:40 6

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Replace duplicate files by hardlinks

Rename all images in current directory to filename based on year, month, day and time based on exif information

find your release version of your ubuntu / debian distro

Print out your hard drive to a jet-direct compatible printer.

Where 192.168.1.2 is a printer with jet-direct. No, I don't suggest this as a backup method.

Convert PNG to GIF

(relies on 'imagemagick') Convert all .png files to .gif. This can also go the other way if you reverse the file extensions in the command, e.g.: $ for file in *.gif; do convert "$file" "$(basename $file .gif).png"; done If the file is named 'example1.png' it will be named 'example1.gif' when it is complete.

capture selected window

Save man pages to pdf

Install pip with Proxy

Installs pip packages defining a proxy

Resume a partially copied file

list process ids for given program

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