peteristhegreat · September 2, 2023 17:09
diff --git a/linux-one-liners.md b/linux-one-liners.md
diff --git a/linux_notes.sh b/linux_notes.sh
 su myuser -c "export DISPLAY=localhost:0.0; background_cmd &"

 cat file1.txt file2.txt > file3.txt; mv file3.txt file2.txt   # prepend one file onto another
 ll -R				# recursively do an ll command
 rm -rf <dir>	# remove a non-empty directory
 pv *.tar.gz | tar -xz
 tar -xvf	file.tar.gz
 tar -xvf file.tar.bz2
 ln -s <target> <symbol>
 . /etc/profile		# shorthand for calling source, basically reloads the session
 grep -r "text" <dir>
 unlink <symbol>
 ldd <executable>		# list dependent libraries
 chmod 664 <file(s)>
 chmod 775 <directory>/
 chmod u+x <script_name>		# make a file executable
 unzip file.zip -d folder	# unzip a file to a folder
 df -h		# show disk space, human readable
 du   # instead run "baobab" for a gui version that's better
 du -sh ./*		# show folder's disk usage
 mkdir -p path/to/make		# make the directory for an entire path
 tree -f | grep "GLOBALS"  # show the full file path (and all symlinks) when listing files in a tree, and then search it
 tree -d			# only show directories, no files
 top	f -show columns
 top	j	processor core
 top	<space>	close
 top	i	multicore info
 top	1	list total core usages
 htop
 chgrp -R mygroup src # change a folder recursively to the RTSS group

 > logfile.txt			# truncate log file
 xrdb ~/.Xdefaults

 pound!/usr/bin/env bash #bash shebang
 set -x				# debugging bash scripts
 set +x				# no more debugging bash script
 exec bash			# clear all env variables

 gdb /path/to/executable /path/to/core/dump        type bt  # how to analyze a core dump
 gdb                                               info locals
 gdb                                               bt full

 git show --pretty="" --name-only HEAD  # show the filenames only from a recent commit
 git diff-tree --no-commit-id --name-only HEAD # same as above
 git checkout SHA -- file  # cherrypick an older version of a file in place
 git show HEAD^:path/to/main.cpp > old_main.cpp  # checkout an older version of a file to a new name
 git log --name-only --oneline
 git diff 15dc8^!		# only show diff for a single commit
 git diff --color-words
 git diff --color-words=.
 git diff --color-words='[^|]+' event_logger_cfg.txt | ansi2html.sh --bg=dark --palette=solarized  > ~/rev2_diff.html
 git difftool -y -x "colordiff -y -W $COLUMNS" | less -R  # show output in columns
 git diff --color HEAD^ HEAD -G"^[^\*#]" | ansi2html.sh > diff_report.html
 git diff -G"^[^ \*#][^\*#]" 
 git diff -G'(^[^\*# ])|(^#\w)|(^\s+[^\*#])' 
 git diff --stat --color HEAD^ HEAD -G"^[^\*#]" | ansi2html.sh > diff_summary.html
 git log --name-only --oneline		#lists all the file changes, one line per file
 git diff HEAD~15				#diff the working tree with the 15th previous commit
 git diff HEAD~15 HEAD		#diff last commit with the 15th previous commit
 git difftool HEAD^ HEAD		#show a diff between the current files and last commit
 git status --porcelain | grep '^??' | cut -c4- >> .gitignore  # ignore all untracked files
 git ls-files -co --exclude-standard | grep '\.pic$' | xargs git add		# add all of a type recursively to git
 git difftool --cached

 git log --name-only HEAD~5..HEAD --pretty=format:

 ls -lrtd $(git status --porcelain | grep '^.[?M]' | sed 's/^.. //')

 vim   vim -S ~/session.vim
 vim   :mksession  or   :mks!
 vim	gf				# go to file under cursor
 vim	Ctrl-^		# go to prev file
 vim	Ctrl-x,Ctrl-o	# auto complete to (
 vim	Ctrl-x,Ctrl-l	# auto complete to end of line
 vim	gd				# go to definition
 vim	Ctrl-]		# go to ctags definition
 vim	set number
 vim	set nonumber
 vim	Shift-V,<,.,.,.	# Shift indentation left 4 times
 vim	Ctrl-V,Shift-I,# ,<ESC>	# Comment out rows in python
 vim	Ctrl-S, Ctrl-Q		# Lock and unlock scroll
 vim	:<line_strt>,<line_end>s/findtxt/replacetxt/g		# replace all text between lines
 vim	:%!xxd	# switch into hex
 vim	:%!xxd -r	# exit from hex
 vim	:set tw=79			# hard text wrap at 79 characters
 vim	:set formatoptions+=t		# required for the hard text wrap
 vim	:set tw=0			# undo hard text wrapping
 vim	:set list
 vim	:set listchars=eol:$,tab:>-,trail:~,extends:>,precedes:<

 when-changed -1 src/bash_script.bash -c "unbuffer shellcheck %f | head -n$(tput lines)"
 python setup.py install --user

 uname -a		# Get the Linux version
 ls -lR folder | grep ^l		# list all symlinks and what they point to, recursively
 grep "str" filename
 grep -r -I --exclude-dir={.svn,useless_folder} "search_term" .

 gunzip -c file.gz > file 
 timeout 5 unbuffer df -k | grep --line-buffered /mounted_folder | cut -c54-
 grep -ohr -E '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' . # only show the ip addresses that come through
 grep -n -c 3 -i "str" filename	# list lines before and after found lines in file
 grep -v "svn"		# print lines not matching svn
 symlinks -rv .		# show all symlinks in a directory, recursively
 pwd -P				# show the actual path, not symbolic
 qmake -r				# recursively run qmake
 qmake -query		# list all the paths used by qmake
 find . -type f -print0 | xargs -0 dos2unix
 find . -maxdepth 1 -type f -exec mv {} old/ \;
 find . -maxdepth 1 -type f -executable -delete
 find -name "Makefile*" -delete	# find and delete all variants of Makefile
 find . -type f -mmin -120 # find files less than 2 hours old
 find . -type f -mtime -1 # find files modified in the last day
 find . -type f | perl -ne 'print $1 if m/\.([^.\/]+)$/' | sort -u		# unique sorted list of types in directory
 find . -type f -name "*.py"		# find all of type
 du -sh ./* | sort -h ; baobab  #Human readable sort
 sort -o file.txt file.txt  # in place sort
 sudo find . ! -user myuser -exec chown myuser:mygroup {} \;
 find . -name '*condor*.pic' -exec cp --parents \{\} ../p4 \;	# keep the folder structure when copying find results
 echo "__" >> ~/.bashrc				# append onto the end of bashrc
 alias youralias='your cmd'			# basic alias usage
 alias		disable alias by preceeding command with a backslash, ie \xterm
 xterm -e "su - myuser" & # launch myuser properly in a new shell

 rsync -avzhPCO local/path/to/u* user@remote:/remote/path/to/u*
 rsync -azP /home/myuser/ myuser@remote:/home/myuser/
 rsync -azP --exclude=var /home/myuser/ myuser@remote:/home/myuser/
 rsync -a <source>/ <target>/		# copy into a non empty directory
 rsync --dry-run -avh ./usr $HOME		# archive, verbose, human readable, dry-run
 history		# list previous commands
 history -c  # clear list of commands
 fc -l 10 	# list last 10 commands
 fc -l ssh	# list last ssh command
 make -j4		# use 4 jobs with make
 tail -n +1 <filenames> # cat all the files with a heading line
 tail -f <logfile>		# keep an open feed to a file, showing appended lines
 scp <filename> computer_name:/path/to/copy/to

 svn diff -rPREV
 svn			cd $MYFOLDER/src
 svn			mkdir feature_a
 svn			cd feature_a
 svn import <foldername> $SVN_HOST/<foldername>/trunk -m "Initial Import"
 svn co $SVN_HOST/<foldername>/trunk <foldername>

 lp -o landscape <filename>		# print a file in landscape to nearby printer
 firefox http://localhost:631/jobs/?WHICH_JOBS=completed&ORDER=dec&QUERY=myuser ... lp related 
 setterm -blink off
 cat temp.txt | tee output.log		# send output to both stderr, stdout, and a log file

 cd -		# goes to the previous directory
 cd -P <symbolic_linked_directory>	# jumps to full path of sym link
 sudo comment_all_pcs_tabs.py -i *.pic

 bang bang	!!		# run last command
 bang cash	!$		# reuse the last parameter
 bang question mark !?string # reuse based on a wildcard start of the string
 bang with tongue		!****:p	# only print the command, don't run it

 rev <file name>  # print out the reversed contents of filename
 fortune -s  # one sentence fortune
 yes <string> # repeated string
 figlet -f <font> <string> #
 figlet fonts *.flf: banner big block bubble digital ivrit lean mini script shadow

 sed -i -e 's/foo/bar/g' filename  # replace foo with bar in place in filename
 sed -i	# in place
 sed -e '<expression>' #command to run
 sed 's//' # substitution
 sed '//g' # global

 ./configure --prefix=$HOME  # configure a package to install to the home directory
 rpm2cpio <filename>.rpm | cpio -idmv
 find . -name "*.rpm" -type f -print | xargs -I {} bash -c "echo {};rpm2cpio {} | cpio -idmv"
 xargs -L 1 
 for i in ./*; do echo $i; done
 find . -type f -exec my_command {} \;

 xclip -o > helloworld.c   # paste contents of clipboard to a file
 wall "Message"  # Writes to all a message aka broadcast...
 script <session_log_file.txt> # store the entire session until exit
 cat filename.txt | ansi2html.sh --bg=dark --palette=solarized  > filename.html
 cat <<HERE   # How to use HEREDOC in bash and scripts
 HERE
 cat <<-HERE  # Indented HEREDOC with tabs!
 HERE
 unbuffer colored_cmd | most
 ps -ef | grep "process name"
 pgrep "process name"
 ps aux    # show disowned processes

 perl -0777 -pie 's/bar/baz' filename # in place find and replace like sed
 perl ... ./Build install --install_base /home/username/usr # install to non-standard directory
 getent passwd "username" | cut -d ':' -f 5  # print out a user's full name from unix username
 symlinks -r .
 find . -xtype l

 echo "This is the message body" | mutt -a "/path/to/file.to.attach" -s "subject of message" -- [email protected]  # send email to someone with an attachment

 var=${parameter:-defaultValue}

 games   bomber - bovo - kapman - katomic - kblackbox - kblocks - kbounce - kbreakout - kdiamond
 games   - kfourinline - kgoldrunner - killbots - kiriki - kjumpingcube - klines 
 games   - kmahjongg - kmines - knetwalk - kolf - kollision - kpat - kreversi - sol
 games   - konquest - ksudoku - kubrick - lskat - 

 screen -d -m -S shared ---------- setup the shared session
 screen -x shared ---------------- the screen clears and shows a new bash session now inside screen
 export DISPLAY=localhost:0.0 ----- setup display properly for a screen session

 date +%Y%m%d_%H%M%S  # printout a timestamp for a filename that sorts in order nicely

 (shopt -s dotglob; mv -- foo/* .)  # move a directory up a level
diff --git a/z_common_commands_with_oneliner_explanations.rst b/z_common_commands_with_oneliner_explanations.rst
 == Miscellaneous Linux Commands ==

 === Introduction ===

 Linux users are expected to interact with the Linux systems quickly and efficiently.

 A bare minimum number of commands will get you by, but if you are interested in sharing what works for you, or common/favorite one-liners or pieces of your bash script continue reading.

 ==== General Links ====

 https://web.archive.org/web/20161121100913/http://archive.oreilly.com/linux/cmd/

 http://explainshell.com/

 And if it isn't on this page, of course, check Google, StackOverflow, and the man pages (RTFM = Read the Fine Manual).

 === Manual Lookup ===

 man
  show the manual for the command, press `q` to quit, spacebar, page up, page down, arrows to scroll
 <command> -h
  try to show the help or usage of a command
 <command> -?
  try to show the help or usage of a command

 === Wildcards ===
 In bash, you can "glob" together a list of files by throwing in some wildcards.

 abc*
  Find abcd, abce, abcdefghij... and so on and anything else that starts with abc
 "ab c"
  Include the space in the name, can have variables inside
 'ab c'
  Include the space in the name, variables and special characters are treated like regular text

 === Listing Files ===

 ls
  list files, similar to `dir` in windows
 ll
  aliased to `ls -l`, shows columns of info about the list of the files in the directory
 tree
  shows all the files in a directory tree
 ../
  up a directory
 ./
  in the current directory
 /
  the root of the harddrive (like c: in windows)
 pwd
  display the present working directory
 cd
  change directory
 ~
  shorthand for the current user's home directory, like `/home/user`
 <tab>
  auto completes a partially written filename
 <tab><tab>
  lists all the possible filenames for the typed out prefix before the cursor

 === Viewing Text ===

 cat
  dumps the whole file to the screen
 less
  lets you scroll up and down on the file, press q to quit
 more
  lets you page down, only
 most
  lets you scroll up, down, left and right
 head
  show the first few lines of a file
 tail
  show the last few lines of a file
 |
  pipe the output of the command on the left to the command on the right
 echo
  show one line of text
 clear
  clear the current page of text and force the current line to the top of the page
 <Shift><PgUp>
  scroll up to previous lines of text on the terminal
 resize
  fixes poor wrapping of text at the command prompt, necessary after resizing the window, to have the terminal recognize the new column width.

 === Copy / Paste ===

 XConfig needs to be configured properly for this to work:
 - XSelection needs to be changed from `Clipboard` to `Primary`.
 - The session needs to be restarted to see the changes.

 Start a selection with a click drag.

 Fill in a selection to the end with a right click.

 Any selection in linux is auto-copied to the clipboard.

 Paste in xterm (the default terminal in MICADS) with a center click.

 Not installed, but future tool for ease of clipboard access is `xclip`.

 === Text Editors ===

 In general terminal editors are faster to open and interact with files.  On remote systems with lower bandwidth and higher latency, terminal editors are superior.

 nano
  terminal editor... Ctrl+<key> to save, exit, etc.
 vi, vim
  terminal editor... multiple modes, Read, Display, Visual, etc, many special commands start with `:`
  navigation with `hjkl` keys... press `ESC` to get out of a mode...
 emacs
  terminal editor... Ctrl+<key> or Alt+<Key>  (short handed to C <key> and M <key>) for special interactions
 gedit, kate, gvim, xemacs
  graphical editors

 === Creating/Deleting Files and Folders ===
 touch
  make a file, or update the timestamp on a file
 `>`
  capture output on the left into the file or handle on the right
 `>>`
  append output on the left onto the filename on the right
 mkdir
  make a directory
 cp
  copy a file or directory
 mv
  move and/or rename a file
 scp
  secure copy a file or directory from one system to another
 rsync
  remote synchronization between two computers (very powerful)
 rm
  remove a file or directory  (needs `-rf` for non-empty directories)

 === Finding and Filtering Text ===
 grep
  general purpose find inside files tool, successors include: awk, ag
 find
  find a specific filename and sometimes do something with it
 which
  find a file (usually a script or binary executable) in the PATH folders list
 locate
  find a filename (or pattern) on the computer that was in the snapshot index last night at midnight
 uniq
  show only unique lines
 sort
  show the lines sorted alphabetically

 === Bash Variables and Functions ===
 $var
  the dollar sign indicates the start of a variable, usually an environment variable, e.g. $PATH
 alias
  makes a nickname for command(s) with specific options, like `ll` = `ls -l` and `gotis`, or lists all aliases
 function
  makes a reusable function or subroutine, that can handle parameters passed in, a la bash scripting
 export
  makes a variable that lives for the length of the "session" that the user is logged in
 env
  queries and lists all the "exported" variables in the '''env'''ironment for use with the session/login
 xterm
  the text, the command prompt, etc that the session lives in, useful for launching another window
 set
  used for changing/listing options for bash.  Like "set -x" and "set +x" to turn on and off echoing all commands.
 === Bash History ===
 https://www.digitalocean.com/community/tutorials/how-to-use-bash-history-commands-and-expansions-on-a-linux-vps

 !!
  "bang, bang", previous command
 !$
  "bang, cash", previous end parameter
 !xxxxx
  "bang", some letters for previous command, executes the last command that started with those letters
 <ESC>,<Ctrl><E>
  Expands one of the above shortcuts to its full length
 <Ctrl><R>
  Reverse search through command history, with interactive input, repeat <Ctrl><R> to search further back

 === Sessions ===
 su
  switch user, start a session as a different user, or without parameters, starts a super user session
 ssh
  tunnel into another system with a secure shell
 exit
  end a session or shell
 logout
  end a session or shell
 script
  start a new bash session and save all the text output for later review
 screen
  screen manager with terminal emulation, a nify way to keep persistent sessions open across logins, also does shared sessions easily

    screen -d -m -S shared
    screen -x shared

 tmux
  terminal multiplexer, a newer nifty way to keep persistent sessions open across logins (utf support, not installed)
 === Linking & Symlinks ===
 ln -s
  create a symbolic link, one file pointing to the actual file somewhere else on the harddrive
 unlink
  remove a symbolic link

 === Process Control ===
 Ctrl+Z
  Pause a process
 bg
  Move a paused process to the background jobs
 fg
  Move a background job or a paused job to the foreground
 jobs
  List all the jobs associated with the current session
 Ctrl+C
  Kill the current foreground process
 top
  View the current running process on the screen, q to quit, or Ctrl-c
 htop
  Like top, but more colorful and a little more friendly

 === Other Users ===
 w
  list all the other users on the system, and login time, idle time, last command, etc
 wall
  broadcast a message to everyone else on the computer
 write
  send a message to a single other user login to that computer
    `echo "message to send" | write <username>`
 finger
  get identification information about a user's name
 getent passwd "user"
  gets entries about a user from the passwd administrative database

 === Printing ===
 lp
  sends a file to the printer address under LPDEST

 === Permissions ===
 chmod
  change the permissions for a file, who can execute, read, write, etc.
 chgrp
  change what group has access to a file
 chown
  change what user owns the file
 sudo
  '''S'''uper '''u'''ser '''do''', or take action with elevated permissions for the current user
 
 === Zipping / Unzipping ===
 tar
  stands for tape archive, many options for compressing and decompressing files, great for .tar, .tar.bz, .tar.gz and others
 unzip
  unzip a file

 === Diffing and Versioning ===
 diff
  show all the differences between two files
 tkdiff
  show all the differences between two files, graphical window
 svn
  centralized versioning system
 git
  distributed versioning system, awesome (see [attachment:progit-en.1084.pdf Git Book (cached)] or [https://progit2.s3.amazonaws.com/en/2016-03-22-f3531/progit-en.1084.pdf Git Book])

 === Scripting Language Interpreters ===
 Script files are read a line at a time, and interpreted at run time, plain text files.

 perl
  files end in pl, original support for Regular Expressions (aka regex or regexp)
 python
  files end in py, popular language
 bash
  stands for borne again shell, and is the language that handles all the input to the command-line
 sh
  posix standard shell command script
 ruby
  files end in rb, popular language, newer than python

 === Compilers and Library Tools ===
 These files are compiled down to a binary file.

 gcc
  c compiler
 g++
  c++ compiler
 ld
  linker, connects complied .o files into an executable
 make
  manages compiling and linking process for most projects in a Makefile
 configure
  provides inputs for the Makefile that are specific to the system/install

 === Disk Utilities ===

 du
  '''d'''isk '''u'''sage, estimate file space usage - space used under a particular directory or files on a file system.

  `du -sh ./*`
    show the filesize of each sub folder in the current directory

 df
  '''d'''isk '''f'''ree, report file system disk space usage, also useful for checking for nfs mounts

  `df -h`
    show all the mounted disks and their used/available size

 dd
  '''d'''ata '''d'''escription, convert and copy a file, also used for cloning partitions and harddisks


 == GUI Applications ==

 From an ssh session, run `gnome-session` to start a GNOME/Ubuntu style desktop or run `plasma-desktop` to start a KDE/Plasma style desktop.

 The gnome session is the default way that a ubuntu user logs into the computer.

 === Categories ===

 Note: search one of these on this page to find an app


 === GUI apps with Shortcuts ===

 || Notes || Shortcut || Name || Comment || Categories || Exec ||

 === Generator Script ===

 You can find these apps in the kickoff launcher in the corner of `plasma-desktop`.

 Generate the table below

 	cd /usr/share/applications
 	find_and_strip ()
 	{      
 		str=$(grep -rhoP "(?<=^($1)).*" $2); 
 		echo $str; 
 	}
 	(
 	for i in * */*; 
 	do 
 	  if [ -d $i ]; then 
 		 continue; 
 	  fi; 
 	  echo -e "$i\t$(find_and_strip "Name=" $i)\t$(find_and_strip "Comment=" $i)\t$(find_and_strip "Categories=" $i)\t$(find_and_strip "Exec=" $i)"; 
 	  done) | xclip
	su myuser -c "export DISPLAY=localhost:0.0; background_cmd &"

	cat file1.txt file2.txt > file3.txt; mv file3.txt file2.txt # prepend one file onto another
	ll -R # recursively do an ll command
	rm -rf <dir> # remove a non-empty directory
	pv *.tar.gz \| tar -xz
	tar -xvf file.tar.gz
	tar -xvf file.tar.bz2
	ln -s <target> <symbol>
	. /etc/profile # shorthand for calling source, basically reloads the session
	grep -r "text" <dir>
	unlink <symbol>
	ldd <executable> # list dependent libraries
	chmod 664 <file(s)>
	chmod 775 <directory>/
	chmod u+x <script_name> # make a file executable
	unzip file.zip -d folder # unzip a file to a folder
	df -h # show disk space, human readable
	du # instead run "baobab" for a gui version that's better
	du -sh ./* # show folder's disk usage
	mkdir -p path/to/make # make the directory for an entire path
	tree -f \| grep "GLOBALS" # show the full file path (and all symlinks) when listing files in a tree, and then search it
	tree -d # only show directories, no files
	top f -show columns
	top j processor core
	top <space> close
	top i multicore info
	top 1 list total core usages
	htop
	chgrp -R mygroup src # change a folder recursively to the RTSS group

	> logfile.txt # truncate log file
	xrdb ~/.Xdefaults

	pound!/usr/bin/env bash #bash shebang
	set -x # debugging bash scripts
	set +x # no more debugging bash script
	exec bash # clear all env variables

	gdb /path/to/executable /path/to/core/dump type bt # how to analyze a core dump
	gdb info locals
	gdb bt full

	git show --pretty="" --name-only HEAD # show the filenames only from a recent commit
	git diff-tree --no-commit-id --name-only HEAD # same as above
	git checkout SHA -- file # cherrypick an older version of a file in place
	git show HEAD^:path/to/main.cpp > old_main.cpp # checkout an older version of a file to a new name
	git log --name-only --oneline
	git diff 15dc8^! # only show diff for a single commit
	git diff --color-words
	git diff --color-words=.
	git diff --color-words='[^\|]+' event_logger_cfg.txt \| ansi2html.sh --bg=dark --palette=solarized > ~/rev2_diff.html
	git difftool -y -x "colordiff -y -W $COLUMNS" \| less -R # show output in columns
	git diff --color HEAD^ HEAD -G"^[^\*#]" \| ansi2html.sh > diff_report.html
	git diff -G"^[^ \#][^\#]"
	git diff -G'(^[^\# ])\|(^#\w)\|(^\s+[^\#])'
	git diff --stat --color HEAD^ HEAD -G"^[^\*#]" \| ansi2html.sh > diff_summary.html
	git log --name-only --oneline #lists all the file changes, one line per file
	git diff HEAD~15 #diff the working tree with the 15th previous commit
	git diff HEAD~15 HEAD #diff last commit with the 15th previous commit
	git difftool HEAD^ HEAD #show a diff between the current files and last commit
	git status --porcelain \| grep '^??' \| cut -c4- >> .gitignore # ignore all untracked files
	git ls-files -co --exclude-standard \| grep '\.pic$' \| xargs git add # add all of a type recursively to git
	git difftool --cached

	git log --name-only HEAD~5..HEAD --pretty=format:

	ls -lrtd $(git status --porcelain \| grep '^.[?M]' \| sed 's/^.. //')

	vim vim -S ~/session.vim
	vim :mksession or :mks!
	vim gf # go to file under cursor
	vim Ctrl-^ # go to prev file
	vim Ctrl-x,Ctrl-o # auto complete to (
	vim Ctrl-x,Ctrl-l # auto complete to end of line
	vim gd # go to definition
	vim Ctrl-] # go to ctags definition
	vim set number
	vim set nonumber
	vim Shift-V,<,.,.,. # Shift indentation left 4 times
	vim Ctrl-V,Shift-I,# ,<ESC> # Comment out rows in python
	vim Ctrl-S, Ctrl-Q # Lock and unlock scroll
	vim :<line_strt>,<line_end>s/findtxt/replacetxt/g # replace all text between lines
	vim :%!xxd # switch into hex
	vim :%!xxd -r # exit from hex
	vim :set tw=79 # hard text wrap at 79 characters
	vim :set formatoptions+=t # required for the hard text wrap
	vim :set tw=0 # undo hard text wrapping
	vim :set list
	vim :set listchars=eol:$,tab:>-,trail:~,extends:>,precedes:<

	when-changed -1 src/bash_script.bash -c "unbuffer shellcheck %f \| head -n$(tput lines)"
	python setup.py install --user

	uname -a # Get the Linux version
	ls -lR folder \| grep ^l # list all symlinks and what they point to, recursively
	grep "str" filename
	grep -r -I --exclude-dir={.svn,useless_folder} "search_term" .

	gunzip -c file.gz > file
	timeout 5 unbuffer df -k \| grep --line-buffered /mounted_folder \| cut -c54-
	grep -ohr -E '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' . # only show the ip addresses that come through
	grep -n -c 3 -i "str" filename # list lines before and after found lines in file
	grep -v "svn" # print lines not matching svn
	symlinks -rv . # show all symlinks in a directory, recursively
	pwd -P # show the actual path, not symbolic
	qmake -r # recursively run qmake
	qmake -query # list all the paths used by qmake
	find . -type f -print0 \| xargs -0 dos2unix
	find . -maxdepth 1 -type f -exec mv {} old/ \;
	find . -maxdepth 1 -type f -executable -delete
	find -name "Makefile*" -delete # find and delete all variants of Makefile
	find . -type f -mmin -120 # find files less than 2 hours old
	find . -type f -mtime -1 # find files modified in the last day
	find . -type f \| perl -ne 'print $1 if m/\.([^.\/]+)$/' \| sort -u # unique sorted list of types in directory
	find . -type f -name "*.py" # find all of type
	du -sh ./* \| sort -h ; baobab #Human readable sort
	sort -o file.txt file.txt # in place sort
	sudo find . ! -user myuser -exec chown myuser:mygroup {} \;
	find . -name 'condor.pic' -exec cp --parents \{\} ../p4 \; # keep the folder structure when copying find results
	echo "__" >> ~/.bashrc # append onto the end of bashrc
	alias youralias='your cmd' # basic alias usage
	alias disable alias by preceeding command with a backslash, ie \xterm
	xterm -e "su - myuser" & # launch myuser properly in a new shell

	rsync -avzhPCO local/path/to/u* user@remote:/remote/path/to/u*
	rsync -azP /home/myuser/ myuser@remote:/home/myuser/
	rsync -azP --exclude=var /home/myuser/ myuser@remote:/home/myuser/
	rsync -a <source>/ <target>/ # copy into a non empty directory
	rsync --dry-run -avh ./usr $HOME # archive, verbose, human readable, dry-run
	history # list previous commands
	history -c # clear list of commands
	fc -l 10 # list last 10 commands
	fc -l ssh # list last ssh command
	make -j4 # use 4 jobs with make
	tail -n +1 <filenames> # cat all the files with a heading line
	tail -f <logfile> # keep an open feed to a file, showing appended lines
	scp <filename> computer_name:/path/to/copy/to

	svn diff -rPREV
	svn cd $MYFOLDER/src
	svn mkdir feature_a
	svn cd feature_a
	svn import <foldername> $SVN_HOST/<foldername>/trunk -m "Initial Import"
	svn co $SVN_HOST/<foldername>/trunk <foldername>

	lp -o landscape <filename> # print a file in landscape to nearby printer
	firefox http://localhost:631/jobs/?WHICH_JOBS=completed&ORDER=dec&QUERY=myuser ... lp related
	setterm -blink off
	cat temp.txt \| tee output.log # send output to both stderr, stdout, and a log file

	cd - # goes to the previous directory
	cd -P <symbolic_linked_directory> # jumps to full path of sym link
	sudo comment_all_pcs_tabs.py -i *.pic

	bang bang !! # run last command
	bang cash !$ # reuse the last parameter
	bang question mark !?string # reuse based on a wildcard start of the string
	bang with tongue !****:p # only print the command, don't run it

	rev <file name> # print out the reversed contents of filename
	fortune -s # one sentence fortune
	yes <string> # repeated string
	figlet -f <font> <string> #
	figlet fonts *.flf: banner big block bubble digital ivrit lean mini script shadow

	sed -i -e 's/foo/bar/g' filename # replace foo with bar in place in filename
	sed -i # in place
	sed -e '<expression>' #command to run
	sed 's//' # substitution
	sed '//g' # global

	./configure --prefix=$HOME # configure a package to install to the home directory
	rpm2cpio <filename>.rpm \| cpio -idmv
	find . -name "*.rpm" -type f -print \| xargs -I {} bash -c "echo {};rpm2cpio {} \| cpio -idmv"
	xargs -L 1
	for i in ./*; do echo $i; done
	find . -type f -exec my_command {} \;

	xclip -o > helloworld.c # paste contents of clipboard to a file
	wall "Message" # Writes to all a message aka broadcast...
	script <session_log_file.txt> # store the entire session until exit
	cat filename.txt \| ansi2html.sh --bg=dark --palette=solarized > filename.html
	cat <<HERE # How to use HEREDOC in bash and scripts
	HERE
	cat <<-HERE # Indented HEREDOC with tabs!
	HERE
	unbuffer colored_cmd \| most
	ps -ef \| grep "process name"
	pgrep "process name"
	ps aux # show disowned processes

	perl -0777 -pie 's/bar/baz' filename # in place find and replace like sed
	perl ... ./Build install --install_base /home/username/usr # install to non-standard directory
	getent passwd "username" \| cut -d ':' -f 5 # print out a user's full name from unix username
	symlinks -r .
	find . -xtype l

	echo "This is the message body" \| mutt -a "/path/to/file.to.attach" -s "subject of message" -- [email protected] # send email to someone with an attachment

	var=${parameter:-defaultValue}

	games bomber - bovo - kapman - katomic - kblackbox - kblocks - kbounce - kbreakout - kdiamond
	games - kfourinline - kgoldrunner - killbots - kiriki - kjumpingcube - klines
	games - kmahjongg - kmines - knetwalk - kolf - kollision - kpat - kreversi - sol
	games - konquest - ksudoku - kubrick - lskat -

	screen -d -m -S shared ---------- setup the shared session
	screen -x shared ---------------- the screen clears and shows a new bash session now inside screen
	export DISPLAY=localhost:0.0 ----- setup display properly for a screen session

	date +%Y%m%d_%H%M%S # printout a timestamp for a filename that sorts in order nicely

	(shopt -s dotglob; mv -- foo/* .) # move a directory up a level
	== Miscellaneous Linux Commands ==

	=== Introduction ===

	Linux users are expected to interact with the Linux systems quickly and efficiently.

	A bare minimum number of commands will get you by, but if you are interested in sharing what works for you, or common/favorite one-liners or pieces of your bash script continue reading.

	==== General Links ====

	https://web.archive.org/web/20161121100913/http://archive.oreilly.com/linux/cmd/

	http://explainshell.com/

	And if it isn't on this page, of course, check Google, StackOverflow, and the man pages (RTFM = Read the Fine Manual).

	=== Manual Lookup ===

	man
	show the manual for the command, press `q` to quit, spacebar, page up, page down, arrows to scroll
	<command> -h
	try to show the help or usage of a command
	<command> -?
	try to show the help or usage of a command

	=== Wildcards ===
	In bash, you can "glob" together a list of files by throwing in some wildcards.

	abc*
	Find abcd, abce, abcdefghij... and so on and anything else that starts with abc
	"ab c"
	Include the space in the name, can have variables inside
	'ab c'
	Include the space in the name, variables and special characters are treated like regular text

	=== Listing Files ===

	ls
	list files, similar to `dir` in windows
	ll
	aliased to `ls -l`, shows columns of info about the list of the files in the directory
	tree
	shows all the files in a directory tree
	../
	up a directory
	./
	in the current directory
	/
	the root of the harddrive (like c: in windows)
	pwd
	display the present working directory
	cd
	change directory
	~
	shorthand for the current user's home directory, like `/home/user`
	<tab>
	auto completes a partially written filename
	<tab><tab>
	lists all the possible filenames for the typed out prefix before the cursor

	=== Viewing Text ===

	cat
	dumps the whole file to the screen
	less
	lets you scroll up and down on the file, press q to quit
	more
	lets you page down, only
	most
	lets you scroll up, down, left and right
	head
	show the first few lines of a file
	tail
	show the last few lines of a file
	\|
	pipe the output of the command on the left to the command on the right
	echo
	show one line of text
	clear
	clear the current page of text and force the current line to the top of the page
	<Shift><PgUp>
	scroll up to previous lines of text on the terminal
	resize
	fixes poor wrapping of text at the command prompt, necessary after resizing the window, to have the terminal recognize the new column width.

	=== Copy / Paste ===

	XConfig needs to be configured properly for this to work:
	- XSelection needs to be changed from `Clipboard` to `Primary`.
	- The session needs to be restarted to see the changes.

	Start a selection with a click drag.

	Fill in a selection to the end with a right click.

	Any selection in linux is auto-copied to the clipboard.

	Paste in xterm (the default terminal in MICADS) with a center click.

	Not installed, but future tool for ease of clipboard access is `xclip`.

	=== Text Editors ===

	In general terminal editors are faster to open and interact with files. On remote systems with lower bandwidth and higher latency, terminal editors are superior.

	nano
	terminal editor... Ctrl+<key> to save, exit, etc.
	vi, vim
	terminal editor... multiple modes, Read, Display, Visual, etc, many special commands start with `:`
	navigation with `hjkl` keys... press `ESC` to get out of a mode...
	emacs
	terminal editor... Ctrl+<key> or Alt+<Key> (short handed to C <key> and M <key>) for special interactions
	gedit, kate, gvim, xemacs
	graphical editors

	=== Creating/Deleting Files and Folders ===
	touch
	make a file, or update the timestamp on a file
	`>`
	capture output on the left into the file or handle on the right
	`>>`
	append output on the left onto the filename on the right
	mkdir
	make a directory
	cp
	copy a file or directory
	mv
	move and/or rename a file
	scp
	secure copy a file or directory from one system to another
	rsync
	remote synchronization between two computers (very powerful)
	rm
	remove a file or directory (needs `-rf` for non-empty directories)

	=== Finding and Filtering Text ===
	grep
	general purpose find inside files tool, successors include: awk, ag
	find
	find a specific filename and sometimes do something with it
	which
	find a file (usually a script or binary executable) in the PATH folders list
	locate
	find a filename (or pattern) on the computer that was in the snapshot index last night at midnight
	uniq
	show only unique lines
	sort
	show the lines sorted alphabetically

	=== Bash Variables and Functions ===
	$var
	the dollar sign indicates the start of a variable, usually an environment variable, e.g. $PATH
	alias
	makes a nickname for command(s) with specific options, like `ll` = `ls -l` and `gotis`, or lists all aliases
	function
	makes a reusable function or subroutine, that can handle parameters passed in, a la bash scripting
	export
	makes a variable that lives for the length of the "session" that the user is logged in
	env
	queries and lists all the "exported" variables in the '''env'''ironment for use with the session/login
	xterm
	the text, the command prompt, etc that the session lives in, useful for launching another window
	set
	used for changing/listing options for bash. Like "set -x" and "set +x" to turn on and off echoing all commands.
	=== Bash History ===
	https://www.digitalocean.com/community/tutorials/how-to-use-bash-history-commands-and-expansions-on-a-linux-vps

	!!
	"bang, bang", previous command
	!$
	"bang, cash", previous end parameter
	!xxxxx
	"bang", some letters for previous command, executes the last command that started with those letters
	<ESC>,<Ctrl><E>
	Expands one of the above shortcuts to its full length
	<Ctrl><R>
	Reverse search through command history, with interactive input, repeat <Ctrl><R> to search further back

	=== Sessions ===
	su
	switch user, start a session as a different user, or without parameters, starts a super user session
	ssh
	tunnel into another system with a secure shell
	exit
	end a session or shell
	logout
	end a session or shell
	script
	start a new bash session and save all the text output for later review
	screen
	screen manager with terminal emulation, a nify way to keep persistent sessions open across logins, also does shared sessions easily

	screen -d -m -S shared
	screen -x shared

	tmux
	terminal multiplexer, a newer nifty way to keep persistent sessions open across logins (utf support, not installed)
	=== Linking & Symlinks ===
	ln -s
	create a symbolic link, one file pointing to the actual file somewhere else on the harddrive
	unlink
	remove a symbolic link

	=== Process Control ===
	Ctrl+Z
	Pause a process
	bg
	Move a paused process to the background jobs
	fg
	Move a background job or a paused job to the foreground
	jobs
	List all the jobs associated with the current session
	Ctrl+C
	Kill the current foreground process
	top
	View the current running process on the screen, q to quit, or Ctrl-c
	htop
	Like top, but more colorful and a little more friendly

	=== Other Users ===
	w
	list all the other users on the system, and login time, idle time, last command, etc
	wall
	broadcast a message to everyone else on the computer
	write
	send a message to a single other user login to that computer
	`echo "message to send" \| write <username>`
	finger
	get identification information about a user's name
	getent passwd "user"
	gets entries about a user from the passwd administrative database

	=== Printing ===
	lp
	sends a file to the printer address under LPDEST

	=== Permissions ===
	chmod
	change the permissions for a file, who can execute, read, write, etc.
	chgrp
	change what group has access to a file
	chown
	change what user owns the file
	sudo
	'''S'''uper '''u'''ser '''do''', or take action with elevated permissions for the current user

	=== Zipping / Unzipping ===
	tar
	stands for tape archive, many options for compressing and decompressing files, great for .tar, .tar.bz, .tar.gz and others
	unzip
	unzip a file

	=== Diffing and Versioning ===
	diff
	show all the differences between two files
	tkdiff
	show all the differences between two files, graphical window
	svn
	centralized versioning system
	git
	distributed versioning system, awesome (see [attachment:progit-en.1084.pdf Git Book (cached)] or [https://progit2.s3.amazonaws.com/en/2016-03-22-f3531/progit-en.1084.pdf Git Book])

	=== Scripting Language Interpreters ===
	Script files are read a line at a time, and interpreted at run time, plain text files.

	perl
	files end in pl, original support for Regular Expressions (aka regex or regexp)
	python
	files end in py, popular language
	bash
	stands for borne again shell, and is the language that handles all the input to the command-line
	sh
	posix standard shell command script
	ruby
	files end in rb, popular language, newer than python

	=== Compilers and Library Tools ===
	These files are compiled down to a binary file.

	gcc
	c compiler
	g++
	c++ compiler
	ld
	linker, connects complied .o files into an executable
	make
	manages compiling and linking process for most projects in a Makefile
	configure
	provides inputs for the Makefile that are specific to the system/install

	=== Disk Utilities ===

	du
	'''d'''isk '''u'''sage, estimate file space usage - space used under a particular directory or files on a file system.

	`du -sh ./*`
	show the filesize of each sub folder in the current directory

	df
	'''d'''isk '''f'''ree, report file system disk space usage, also useful for checking for nfs mounts

	`df -h`
	show all the mounted disks and their used/available size

	dd
	'''d'''ata '''d'''escription, convert and copy a file, also used for cloning partitions and harddisks


	== GUI Applications ==

	From an ssh session, run `gnome-session` to start a GNOME/Ubuntu style desktop or run `plasma-desktop` to start a KDE/Plasma style desktop.

	The gnome session is the default way that a ubuntu user logs into the computer.

	=== Categories ===

	Note: search one of these on this page to find an app


	=== GUI apps with Shortcuts ===

	\|\| Notes \|\| Shortcut \|\| Name \|\| Comment \|\| Categories \|\| Exec \|\|

	=== Generator Script ===

	You can find these apps in the kickoff launcher in the corner of `plasma-desktop`.

	Generate the table below

	cd /usr/share/applications
	find_and_strip ()
	{
	str=$(grep -rhoP "(?<=^($1)).*" $2);
	echo $str;
	}
	(
	for i in * /;
	do
	if [ -d $i ]; then
	continue;
	fi;
	echo -e "$i\t$(find_and_strip "Name=" $i)\t$(find_and_strip "Comment=" $i)\t$(find_and_strip "Categories=" $i)\t$(find_and_strip "Exec=" $i)";
	done) \| xclip