Posix

commandlinefu

 * http://www.commandlinefu.com/commands/browse/25
 * http://www.commandlinefu.com/commands/view/19641/dd-with-progress-bar-and-statistics#comment
 * python -m SimpleHTTPServer #serve current directory at  http://localhost:8000

sh
https://sites.google.com/site/jdisnard/path-dupes remove duplicate paths. http://unix.stackexchange.com/questions/40749/remove-duplicate-path-entries-with-awk-command
 * https://stackoverflow.com/questions/793858/how-to-mkdir-only-if-a-dir-does-not-already-exist?rq=1 create directory.
 * https://stackoverflow.com/questions/8748831/when-do-we-need-curly-braces-in-variables-using-bash Curly braces.


 * http://www.tldp.org/LDP/abs/abs-guide.pdf 900 page guide
 * https://linuxacademy.com/blog/linux/conditions-in-bash-scripting-if-statements/ file conditions etc.
 * http://www.tutorialspoint.com/unix_commands/sh.htm
 * https://www.macs.hw.ac.uk/~hwloidl/Courses/LinuxIntro/x945.html
 * https://opensource.com/article/17/6/bash-parameter-expansion parameter expansion
 * Grep

Forums

 * http://www.unix.com/shell-programming-and-scripting/170808-bash-clearing-value-variable.html
 * http://www.unix.com/
 * https://www.dwheeler.com/essays/filenames-in-shell.html

Unix stackexchange
https://unix.stackexchange.com/questions/23271/pipes-vs-process-substitution?rq=1

tutorials
https://ryanstutorials.net/bash-scripting-tutorial/bash-if-statements.php
 * http://mywiki.wooledge.org/BashFAQ/055, http://wiki.bash-hackers.org/scripting/copydescriptor redirecting 2>&1
 * http://wiki.bash-hackers.org/scripting/tutoriallist?s[]=links
 * http://guide.bash.academy
 * http://wiki.bash-hackers.org
 * http://www.gnu.org/software/bash/manual/bashref.html redirecting input, output piping section 3.6
 * http://sourcemage.org/Sorcery/Book shell style guide, a clone of Linuxfromscratch.com
 * http://www.codebind.com/linux-tutorials/bash-shell-scripting-statement-fi-else-fi-elif-else-fi/ if then else

http://tldp.org/LDP/abs/html/complexfunct.html

https://www.dartmouth.edu/~rc/classes/ksh/print_pages.shtml

https://sipb.mit.edu/doc/safe-shell/

http://www.davidpashley.com/articles/writing-robust-shell-scripts/

https://www.turnkeylinux.org/blog/shell-error-handling

https://www.cons.org/cracauer/sigint.html

functions

 * https://stackoverflow.com/questions/64786/error-handling-in-bash/185900#185900
 * https://ubuntuforums.org/showthread.php?t=664657 store functions in separate file.
 * http://redsymbol.net/articles/bash-exit-traps/ exit traps
 * https://github.com/parallella/parallella-flash/blob/master/common.sh
 * https://github.com/parallella/parallella-flash/blob/master/linux/linux-flash.sh

http://www.codegist.net/code/bash-execute-gist/

youtube
https://www.youtube.com/watch?v=xC5NKqXmdUo Record All Screen Output to File - BASH -Linux 4,678 views

cat
https://stackoverflow.com/questions/2500436/how-does-cat-eof-work-in-bash

links
http://www.linux-mag.com/
 * LinuxNotes, ShellCommands Mesh networking shell commands

http://www.linux-mag.com/id/8797/