Commands by pooderbill (4)

  • Useful for finding newly added lines to a file, tail + can be used to show only the lines starting at some offset. A syslog scanner would look at the file for the first time, then record the end_of_file record number using wc -l. Later (hours, days), scan only at the lines that were added since the last scan. Show Sample Output


    1
    tail +### MYFILE
    pooderbill · 2015-04-23 11:49:15 14
  • view is the command: vi -r which opens a file in read-only mode. The + character jumps to the bottom of the logfile where the most relevant information starts. Other aliases can be created for commonly viewed logfiles. Show Sample Output


    -1
    view + LOGFILE
    pooderbill · 2015-04-21 11:23:01 12
  • 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. Show Sample Output


    14
    ps -fC PROCESSNAME
    pooderbill · 2015-04-20 13:09:44 17
  • The shortest and most complete comment/blank line remover... Any line where the first non-whitespace character is # (ie, indented # comments), and all null and blank lines are removed. Use the alias as a filter: noc /etc/hosts or grep server /etc/hosts | noc Change to nawk depending awk versions. Show Sample Output


    1
    alias noc="awk 'NF && ! /^[[:space:]]*#/'"
    pooderbill · 2014-09-07 00:50:57 72

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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"

kill all process that belongs to you
This will probably kill any user sessions and/or ssh connections to other servers you might have active.

convert strings toupper/tolower with tr

return a titlecased version of the string
Needs Bash4. Found at http://stackoverflow.com/questions/2264428/converting-string-to-lower-case-in-bash-shell-scripting alongside a few other tricks.

Find dupe files by checking md5sum

Create incremental snapshots of individual folders using find and tar-gzip
Creates an incremental snapshot of individual folders.

Record microphone input and output to date stamped mp3 file
record audio notes or meetings requires arecord and lame run mp3gain on the resulting file to increase the volume / quality ctrl-c to stop recording

download all the presentations from UTOSC2010
miss a class at UTOSC2010? need a refresher? use this to curl down all the presentations from the UTOSC website. (http://2010.utosc.com) NOTE/WARNING this will dump them in the current directory and there are around 37 and some are big - tested on OSX10.6.1

list file descriptors opened by a process
Useful for examining hostile processes (backdoors,proxies)

Detect illegal access to kernel space, potentially useful for Meltdown detection
Based on capsule8 agent examples, not rigorously tested


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