• 1. One you use to log into http://voip.ms to configure the account
• 2. One you use to enter into a phone handset. The username is the 6-digit number they provide in the welcome email when you create an account.

• Make a phone number, called a DID (which stands for "Direct Inward Dial")
  • Log into voip.ms
  • Select "DID Numbers" menu and then select "Order DID(s)"
  • Choose a state and rate center
  • Click "View Numbers"
  • Select a number
  • Select a plan, per min or flat rate
  • Select a server. This must be the same as configured in the phone app
  • Click "Order DID", then "Confirm Order"

• Configure the DID
  • Log into voip.ms
  • Select "Manage DID Numbers" at the menu bar at the top of the page
  • Select the chckbox next to a phone number
  • Select "Edit selection - all settings at once
  • Under "Message Service" Section
    • Select "Message Service"
    • Select "Link the SMS received to this DID to a SIP account"
    • Click "Click here to apply changes"
  
  
  

  ---

  Connecting to Synology NAS

  A few common steps that I follow when managing disks on Synology NAS. Note - this is Fedora specific but may be close to what you would do on another distro.

  Mount the NAS on a Linux Client

  • Now look for IP addresses of other machines to see what is in use. This should confirm that the static IP we set up above is visible.
    • dnf install nmap
    • nmap -sn 192.168.0.0/24
    • nmap -sT -O 192.168.0.0/24
      --or--
    • nmap -sn 192.168.1.0/24
    • nmap -sT -O 192.168.1.0/24

  • Install the CIFS client software
    • sudo -i
    • dnf install cifs-utils
  • Make a place to mount the remove server
    • sudo -i
    • cd /
    • mkdir nas
    • chmod ugo+rwx nas

  • Modify your /etc/fstab file.
    WARNING!!!!! Do NOT change any other line in the /etc/fstab file. This can make your system unusable and require a complete new OS install!!!! Only APPEND a new line. You have been warned.

    192.168.0.227:/volume1/fileRoot /nas nfs rw,hard,intr,rsize=8192,wsize=8192,timeo=14 0 0
    

  • Reload the modified /etc/fstab file to remount all file systems
    • systemctl daemon-reload
    • mount -a
  
  
  

  ---

  Installing and configuring WSGI on Apache

  A few common steps that I follow when running WSGI on Apache. This is *not* a stand-alone server, but rather adds WSGI as a backend for Apache. Note - this is Fedora specific but may be close to what you would do on another distro.

  Some useful docs are at: https://modwsgi.readthedocs.io/en/master/user-guides/quick-configuration-guide.html

  • dnf install mod_wsgi
  • /etc/init.d/httpd stop or apachectl -k stop
  • Edit /etc/httpd/conf/httpd.conf
    • Add this line after "Include conf.modules.d/*.conf"

          LoadModule wsgi_module modules/mod_wsgi.so
          

    • Add this line after "ServerAdmin root@localhost" and before the first

          # WSGI Scripts
          WSGIScriptAlias /myapp /var/www/cgi-bin/test.py
          

      Note, this myst be an absolute path. I know, that is odd, but this file contains all absolute paths. If this is running on AWS or some other hosting service, you can search for the directive "DocumentRoot /var/www/html" to tell you where the root is running.
  • /etc/init.d/httpd start or apachectl -k start
  
  
  

  ---

  Installing and configuring Linux Disks and Samba File Server

  A few common steps that I follow when managing disks and Samba on Fedora. Note - this is Fedora specific but may be close to what you would do on another distro.

  Format and mount a new disk

  • GParted to determine the drive label
    • sudo -1
    • dnf install gparted
    • gparted
    Run gparted to find the device for the new disk. All examples below assume /dev/sda but this will be different for each disk.

  • Partition the disk
    This will make a numeric partition, like /dev/sda1 is the first partition of /dev/sda. Refer to that partition now.
    • fdisk /dev/sda
    • n
    • w
    You can use lsblk to confirm the new partition is created.

  • Make the file system.
    You can use "mkfs -v -t ext4 /dev/sda1" However, I just used gparted.

  • Mount the FS
    • mkdir -v /fsDisk
    • mount --source /dev/sda --target /fsDisk

  • Some useful links:
    • Fedors docs

  Set a Static IP Address for your Server

  This uses a local IP address behind your router, so it is *only* visible on the local network.

  • Get the local network device names
    • sudo -i
    • dnf install lshw
    • lshw -class network

  • Or you can simply do this:
    • ifconfig
    
    So, why is this an odd name, like enp0s31f6 and now "eth0" or something? These are the new "Predictable network interface device names", which remain the same despite different physical and virtual network cards being added and removed. enp0s31f6 refers to ethernet (en), prefix 0 (p0), slot 31 (s31), function 6 (f6)

  • See what the IP address of the local machine is
    • ip addr show

  • Configure an interface with static network settings using ifcfg files For an interface with the name enp0s31f6, create a file with name ifcfg-enp0s31f6 in the /etc/sysconfig/network-scripts/ directory with content similar to this:

    DEVICE=enp0s31f6
    BOOTPROTO=none
    ONBOOT=yes
    NETMASK=255.255.255.0
    IPADDR=192.168.1.10
    USERCTL=yes
    

    See Fedora Docs

  • Reboot and confirm the change
    • ip addr show dev enp0s31f6

  Install and enable Samba

  This also sets the firewall to allow access to Samba from other computers. See Fedora Docs for more. There is also a useful article in Fedora magazine.

  • Install the Samba software and open access to it through the local machine firewall so other machines (even those on your local network) can access it.
    • sudo -i
    • dnf install samba
    • sudo systemctl enable smb --now
    • firewall-cmd --get-active-zones
    • sudo firewall-cmd --permanent --zone=FedoraWorkstation --add-service=samba
    • sudo firewall-cmd --reload

  • Do user and group setup. See the private instructions.

  • Tell Samba that this is a share
    • semanage fcontext --add --type "samba_share_t" /fsDisk
    • restorecon -R /fsDisk

  • Configure Samba
    There is no longer a GUI tool for configuring Samba. There was one in the past but it is no longer supported for a variety of reasons (lack of developer support, known bugs, etc). So, you have to manually edit the /etc/samba/smb.conf file. Below is a very simple smb.conf file that will make one share with NO security (everyone can read/write it). I am using this for my private file share that is behind my router.

    ---

    # Run 'testparm' to verify the config is correct after
    # you modified it.
    #
    # The name of the share is in square brackets [],
    #   this will be shared as //hostname/sharename
    # There are a three exceptions:
    #   the [global] section;
    #   the [homes] section, that is dynamically set to the username;
    #   the [printers] section, same as [homes], but for printers.
    #
    # path: the physical filesystem path (or device)
    # comment: a label on the share, seen on the network.
    # read only: disable writing, defaults to true.
    #
    # Note:
    # SMB1 is disabled by default. This means clients without support for SMB2 or
    # SMB3 are no longer able to connect to smbd (by default).
    #
    # BUG!
    #	workgroup = SAMBA
    #	workgroup = FEDORA
    #	security = user
    #	passdb backend = tdbsam
    #	valid users = %S, %D%w%S
    
    [global]
    	server role = standalone server
    	workgroup = SAMBA
    
    	log file = /var/log/samba/%m
            log level = 1
    	
    [fileroot]
            comment = File System Share
            path = /fsDisk
    	guest ok = yes
            guest only = yes
    	read only = no
    
    	writeable = yes
            browseable = yes
            public = yes
            create mask = 0770
            directory mask = 0770
    

    ---

    By default, Samba uses tdbsam for user information. This is based on “TDB” (trivial database). Also by default the workgroup is "SAMBA".

  • Make sure SMBv1 is disabled
    See https://www.cisa.gov/uscert/ncas/current-activity/2017/01/16/SMB-Security-Best-Practices
    You can add the following to the [global] section of /etc/samba/smb.conf client min protocol = SMB2_02 server min protocol = SMB2_02 However, I leave this out if the config file includes the comment that SMBv1 is disabled.

  • Some useful links:
    • https://docs.fedoraproject.org/en-US/quick-docs/samba/
    • https://fedoramagazine.org/fedora-32-simple-local-file-sharing-with-samba/

  Mount the Samba Share on a Linux Client

  • Now look for IP addresses of other machines to see what is in use. This should confirm that the static IP we set up above is visible.
    • dnf install nmap
    • nmap -sn 192.168.1.0/24
    • nmap -sT -O 192.168.1.0/24

  • Install the CIFS client software
    • sudo -i
    • dnf install cifs-utils
  • Make a place to mount the remove server
    • sudo -i
    • mkdir /fileServer
    • chmod ugo+rwx /fileServer

  • Modify your /etc/fstab file.
    WARNING!!!!! Do NOT change any other line in the /etc/fstab file. This can make your system unusable and require a complete new OS install!!!! Only APPEND a new line. You have been warned.

    //192.168.1.10/fileroot /fileServer cifs guest,vers=3.0,noperm 0 0
    

    The option noperm in fstab tells the client to not do permission checks. This can expose files on this mount to access by other users on the local client system

  • Reload the modified /etc/fstab file to remount all file systems
    • mount -a

  Mount the Samba Share on a Windows Client

  I do not have a good fix here. The big problem seems to be the client cannot authenticate to a Samba server that has no password. I have tried changing the registry keys.

  I have read Microsoft KB notes that say to use "the Local Group Policy Editor (gpedit.msc)". I have also read posts and seen notes saying to use Regedit to add a DWORD named "AllowInsecureGuestAuth" and set its value to 1 under the following keys:

  • HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\LanmanWorkstation\
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters
  See the KB https://docs.microsoft.com/en-us/troubleshoot/windows-server/networking/guest-access-in-smb2-is-disabled-by-default Then they say to use File Explorer to right-click "This PC" and in the context menu select "Add a network location". But this doesn't work for me.

  So, instead I do this:

  • Mount the server to a local drive through the command line
    • net use x: \\192.168.1.10\fileroot /user:"" ""

  • Or mount the server to a local drive through the GUI
    • Right click "This PC" and select the "Map Network Drive..."

  However, this does NOT survive across reboots. After rebooting, it fails to mount the server again because the user name and password are blank. So, I got a bit frustrated (and I don't use Windows daily) and made a shell script which is on the desktop which I have to run to mount the server.

  net use x: /delete
  net use x: \\192.168.1.10\fileroot /user:""  ""
  

  Yes, there is a better way, and yes I am obviously missing something above. But for now, this will get me through.

  Block Access to the SMB Ports from outside the router

  See https://kb.netgear.com/8219/How-to-setup-Inbound-Outbound-firewall-rules-on-NETGEAR-Modem-router-gateways. This will block Internet access to the device but it will be accessible on the LAN to others.
  • Launch an internet browser from a computer or wireless device that is connected to the network. This will be usually one of these:
    • http://www.routerlogin.net
    • http://www.routerlogin.com
    • http://192.168.1.1
    • http://192.168.0.1
    • http://10.0.0.1
  • Click "Advanced" tab
  • Select the "Security > Block Services" section from the pane on the left
  • Under Service Table, click "Add"
  • US-CERT recommends that users and administrators consider:
    • UDP/137 - used by nmbd - incoming UDP datagrams from the local network
    • UDP/138 - used by nmbd - incoming UDP datagrams from the local network
    • TCP/139 - used by smbd - incoming TCP connections
    • TCP/445 - used by smbd - incoming TCP connections
  
  
  

  ---

  Installing and configuring Emacs

  A few common shortcuts that I personally prefer. The blessing/curse of emacs is that it is so customizable, everyone ends up with a slightly different solution. These are what I have come up with so far, but I am also still trying to tweak it to make it more to my liking. Still, you may not like these design choices.

  When testing a .emacs file, you can always use "M-x load-file" and then enter the file name. This will reload the config file without quitting and restarting the program.
  

  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;
  ;; Emacs Customization
  ;; Tips and tricks from many sources, collected by Dawson Dean
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; Font Size and Type
  ;;
  ;; The height is 1/100th of a point, so 100 is a 10pt font.
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  (set-default-font "DejaVu Sans Mono")
  (set-face-attribute 'default nil :height 100)
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; Text Colors
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  (set-face-foreground 'font-lock-string-face "black")
  (set-face-foreground 'font-lock-comment-face "dark green")
  (set-face-foreground 'font-lock-comment-delimiter-face "dark green")
  (set-face-foreground 'font-lock-function-name-face "black")
  (set-face-foreground 'font-lock-variable-name-face "black")
  (set-face-foreground 'font-lock-keyword-face "dark blue")
  (set-face-foreground 'font-lock-type-face "black")
  (set-face-foreground 'font-lock-constant-face "black")
  (set-face-foreground 'font-lock-builtin-face "black")
  (set-face-foreground 'font-lock-preprocessor-face "black")
  
  ;; The color of the mark region
  (set-face-attribute 'region nil :background "#BFEFFF")
  ;; Blue:    0000FF
  ;; Orange:  FFA000
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; Custom Key Bindings
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
  ;; Ctrl-Z is undo.
  (global-set-key (kbd "C-z") 'undo)
  (global-set-key (kbd "C-Z") 'undo)
  
  ;; Ctrl-/ will goto-line
  ;; This is totally unique to me, nobody else agrees on this. Lots of people
  ;; seem to like "Esc-g g" but that's still too many keystrokes for me.
  (define-key global-map (kbd "C-/") 'goto-line)
  
  ;; I sometimes have the Control key held down while doing other things.
  (define-key global-map (kbd "") (kbd ""))
  (define-key global-map (kbd "") [Double-Mouse-1])
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; Basic Editing
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
  ;; Shift-click will extend the mark region
  (define-key global-map (kbd "") 'mouse-save-then-kill)
  
  ;; Typing will replace the currently selected text.
  (delete-selection-mode 1)
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; Syntax Table Hacking
  ;; http://www.emacswiki.org/emacs/EmacsSyntaxTable
  ;;
  ;; Word operations will not treat "_" as a word-break in C++. This puts
  ;; the character "_" (which is quoted with ? so it is ?_) in the "word"
  ;; class of characters (which is identified by "w").
  ;; Really, we just want to evaluate this:  (modify-syntax-entry ?_ "w")
  ;; But we add a hook so our customization is not clobbered every time
  ;; the symbol table is edited.
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  (add-hook 'text-mode-hook (lambda () (modify-syntax-entry ?_ "w")))
  (add-hook 'c-mode-hook (lambda () (modify-syntax-entry ?_ "w")))
  (add-hook 'c++-mode-hook (lambda () (modify-syntax-entry ?_ "w")))
  (add-hook 'html-mode-hook (lambda () (modify-syntax-entry ?_ "w")))
  (add-hook 'xml-mode-hook (lambda () (modify-syntax-entry ?_ "w")))
  (add-hook 'java-mode-hook (lambda () (modify-syntax-entry ?_ "w")))
  (add-hook 'js-mode-hook (lambda () (modify-syntax-entry ?_ "w")))
  (add-hook 'js2-mode-hook (lambda () (modify-syntax-entry ?_ "w")))
  (add-hook 'abbrev-mode-hook (lambda () (modify-syntax-entry ?_ "w")))
  
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; Select the entire buffer
  ;; This was copied (with some small changes) from:
  ;; https://www.gnu.org/software/emacs/manual/html_node/eintr/mark_002dwhole_002dbuffer.html
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  (defun mark-whole-buffer()
         "Select the entire buffer"
         (interactive)
         (message "mark-whole-buffer!")
          ;; Put point at beginning 
         (push-mark (point))
          ;; Put the mark at end of buffer.
         (push-mark (point-max) nil t)
         (goto-char (point-min))
  ) ;; defun
  (global-set-key (kbd "C-S-A") 'mark-whole-buffer)
  
  
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; CUA Mode
  ;;
  ;; This makes Ctl-x cut, Ctl-v paste, and Ctl-C copy.
  ;; This is what you use in Web browsers, so it makes sense for all applications to
  ;; share a common convention.
  ;; http://www.emacswiki.org/emacs/CuaMode
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  (cua-mode t)
  (transient-mark-mode 1) ;; Default in Emacs 23 and later. Selected region is only active when highlighted
  ;;(setq cua-auto-tabify-rectangles nil) ;; Don't tabify after rectangle commands
  ;;(setq cua-keep-region-after-copy t) ;; Standard Windows behaviour
  
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;
  ;; Searching: Find, Find-And-Replace, Grep 
  ;;
  ;; As I switched back to emacs after years on Microsoft's Visual Studio, I realized
  ;; that I use search to navigate around a buffer more than Ctl-V and Esc-V or similar
  ;; things. Here are some functions to find the next and previous instance of the
  ;; currently selected text.
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; Find the next instance of the selected text
  (defun forward-search-selection (beg end)
      "Search for the current selection"
      ;; This tells elisp to call this command with the point and mark
      ;; as arguments parameters bound to beg and end
      (interactive "r")
  
      ;; Save the current selection to a local variable.
      ;; We want to deactivate the mark, so save a private copy first.
      (let (
            (selection (buffer-substring-no-properties beg end))
           )
          ;;(message "selection:%s" selection)
      
          ;; De-activate the current mark region. We will change the mark later
          (deactivate-mark)
  
          ;; Find the next instance of the string.
          ;; https://www.gnu.org/software/emacs/manual/html_node/eintr/search_002dforward.html#search_002dforward
          ;; search-forward takes 4 arguments:
          ;;      The search pattern
          ;;      Optional - limit of search. nil means end of buffer
          ;;      Optional - how to handle failed search. nil means print a message.
          ;;                   t means return a result
          ;;      Optional - How many instances to find
          (when (search-forward selection nil t)
              ;; If search-forward returned true, then it found a match.
              ;; Select the match. This is nice for user feedback but it also
              ;; lets another search-forward find the next occurrence.
              (setf
                  (mark) (match-beginning 0)
                  (point) (match-end 0))
          ) ;; when
      ) ;; let
  ) ;; forward-search-selection
  (define-key global-map (kbd "") 'forward-search-selection)
  
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; Find the previous instance of the selected text
  (defun reverse-search-selection (beg end)
      "Search for the current selection"
      ;; This tells elisp to call this command with the point and mark
      ;; as arguments parameters bound to beg and end
      (interactive "r")
  
      ;; Save the current selection to a local variable.
      ;; We want to deactivate the mark, so save a private copy first.
      (let (
            (selection (buffer-substring-no-properties beg end))
           )
        
          ;; De-activate the current mark region. We will change the mark later
          (deactivate-mark)
  
          ;; Find the prev instance of the string.
          ;; This works like search-forward except it runs in reverse
          ;; search-backward takes 4 arguments:
          ;;      The search pattern
          ;;      Optional - limit of search. nil means end of buffer
          ;;      Optional - how to handle failed search. nil means print a message.
          ;;                   t means return a result
          ;;      Optional - How many instances to find
          
          (when (search-backward selection nil t)
              ;; If search-forward returned true, then it found a match.
              ;; Select the match. This is nice for user feedback but it also
              ;; lets another search-forward find the next occurrence.
              (setf
                  (mark) (match-end 0)
                  (point) (match-beginning 0))
          ) ;; when
      ) ;; let
  ) ;; reverse-search-selection
  (define-key global-map (kbd "") 'reverse-search-selection)
  
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; Replace Text
  
  ;; Replace the next instance of the selected text
  (defun forward-replace-selection (beg end)
      "Search for the current selection"
      ;; This tells elisp to call this command with the point and mark
      ;; as arguments parameters bound to beg and end
      (interactive "r")
  
      ;; Save the current selection to a local variable.
      ;; We want to deactivate the mark, so save a private copy first.
      (let (
            (selection (buffer-substring-no-properties beg end))
           )
          ;; (message "forward-replace-selection:%s" selection)
      
          ;; De-activate the current mark region. We will change the mark later
          (deactivate-mark)
  
          (let (
              (replaceStr (read-from-minibuffer "Replacement: "))
              )
              ;;(message "replaceStr:%s" replaceStr)
  
              ;; Go to the start of the buffer.
              ;; search-forward will only start at the current position.
              (goto-char (point-min))
  
              ;; https://www.gnu.org/software/emacs/manual/html_node/elisp/Search-and-Replace.html
              (while (search-forward selection nil t)
                  ;; https://www.gnu.org/software/emacs/manual/html_node/elisp/Replacing-Match.html
                  ;; replace-match replacement &optional fixedcase literal string subexp
                  ;; fixedcase says to not change the case of the replacement text
                  ;; to match the text being replaced.
                  (replace-match replaceStr t))
          ) ;; let
  
      ) ;; let
  ) ;; forward-replace-selection
  (define-key global-map (kbd "C-r") 'forward-replace-selection)
  
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; Grep
  
  ;; Find the next instance of the selected text
  (defun grep-selection (beg end)
      "Grep for the current selection"
      ;; This tells elisp to call this command with the point and mark
      ;; as arguments parameters bound to beg and end
      (interactive "r")
  
      ;; Save the current selection to a local variable.
      ;; We want to deactivate the mark, so save a private copy first.
      (let (
            (pattern (buffer-substring-no-properties beg end))
           )
          (message "ddGrep:%s" pattern)
      
          ;; De-activate the current mark region. We will change the mark later
          (deactivate-mark)
  
          ;; grep-find is a built-in emacs elisp function.
          ;; See: https://www.gnu.org/software/emacs/manual/html_node/emacs/Grep-Searching.html#Grep-Searching
          ;; See: https://www.gnu.org/software/emacs/manual/html_node/emacs/Grep-Searching.html
  
          ;; The options are the normal command line grep options.
          ;; Here, I use:
          ;;  -e, --regexp=PATTERN      use PATTERN for matching
          ;;  -i, --ignore-case         ignore case distinctions
          ;;  -n, --line-number         print line number with output lines
          ;;  -H, --with-filename       print file name with output lines
          ;;  -R, --recursive           like --directories=recurse, and also follow all symlinks
          ;;
          ;; Some useful topns which are not used now, but may be used later
          ;;  -w, --word-regexp         force PATTERN to match only whole words
          ;;  -x, --line-regexp         force PATTERN to match only whole lines
          ;;  -m, --max-count=NUM       stop after NUM selected lines
          ;;  -h, --no-filename         suppress the file name prefix on output
          ;;  -o, --only-matching       show only the part of a line matching PATTERN
          ;;  --include=FILE_PATTERN    search only files that match FILE_PATTERN
          ;;  -L, --files-without-match print only names of FILEs with no selected lines
          ;;  -l, --files-with-matches  print only names of FILEs with selected lines
          ;;  -T, --initial-tab         make tabs line up (if needed)
          ;;  -B, --before-context=NUM  print NUM lines of leading context
          ;;  -A, --after-context=NUM   print NUM lines of trailing context
          ;;  -C, --context=NUM         print NUM lines of output context
          (grep (concat "grep -i -n -H -R -e \"" (shell-quote-argument pattern) "\" /home/ddean/ddRoot/code"))
      ) ;; let
  ) ;; grep-selection
  (define-key global-map (kbd "") 'grep-selection)
  
  
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;
  ;; Parens and Braces
  ;;
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; Find the matching (open or close) paren
  ;; This was copied (with some small changes) from:
  ;; https://www.gnu.org/software/emacs/manual/html_node/efaq/Matching-parentheses.html
  (defun find-match-paren (arg)
      "Go to the matching paren if on a paren; otherwise insert %."
      (interactive "p")
      (cond
              ((looking-at "\\s(") (forward-list 1) (backward-char 1))
              ((looking-at "\\s)") (forward-char 1) (backward-list 1))
  
              ((looking-at "\\s[") (forward-list 1) (backward-char 1))
              ((looking-at "\\s]") (forward-char 1) (backward-list 1))
      ) ;; cond
  ) ;; defun
  (define-key global-map (kbd "C-]") 'find-match-paren)
  
  ;; Make braces act like parens, and match opens and closes
  (modify-syntax-entry ?{ "(}")
  (modify-syntax-entry ?} "){")
  
  
  
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;
  ;; Tabs and Indentation
  ;;
  ;; http://www.emacswiki.org/emacs/IndentationBasics
  ;; https://stackoverflow.com/questions/344966/improved-tab-in-emacs
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
  ;; Tabs are space characters, not a tab character.
  (setq-default indent-tabs-mode nil)
  
  (global-set-key (kbd "TAB") 'tab-to-tab-stop)
  (setq default-tab-width 4)
  (setq tab-width 4)
  
  ;; tab-width is used when DISPLAYING tabs, while tab-stop-list 
  ;; is needed to determine tab stops when you ADD tabs.
  ;; From emacs documentation, "The variable tab-stop-list controls these positions. The default value is nil, which means a tab stop every 8 columns."
  ;;;(setq-default c-basic-offset 4)
  (setq tab-stop-list (number-sequence 4 200 4))
  
  ;; Be careful. If you set this to newline-and-indent, then emacs
  ;; will autoindent no matter what you set the autoindent options to.
  ;;(global-set-key (kbd "RET") 'newline-and-indent)
  (global-set-key (kbd "RET") 'newline)
  
  ;; Don't use tabs to indent code.
  ;;;(setq-default indent-tabs-mode nil)
  
  ;; Stop emacs from trying to second-guess what it thinks I want.
  (when (fboundp 'electric-indent-mode) (electric-indent-mode -1))
  ;;(setq-default electric-indent-inhibit t)
  
  ;; Pasting a newline does not cause an indent.
  (global-set-key "\C-j" 'newline)
  
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;
  ;; Indenting and Un-Indenting
  ;;
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
  (defun shift-region (distance)
    (let ((mark (mark)))
      (save-excursion
        (indent-rigidly (region-beginning) (region-end) distance)
        (push-mark mark t t)
        ;; Tell the command loop not to deactivate the mark
        ;; for transient mark mode
        (setq deactivate-mark nil))))
  
  (defun shift-right ()
    (interactive)
    (shift-region 4))
  
  (defun shift-left ()
    (interactive)
    (shift-region -4))
  
  ;; C-[ is equivalent to the escape key on US English keyboards
  ;; Changing  C-[ will break things like Esc-x
  (global-set-key (kbd "C-]") 'shift-right)
  (global-set-key (kbd "C-.") 'shift-right)
  (global-set-key (kbd "C-,") 'shift-left)
  
  
  
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;; Backup Files
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  (setq backup-directory-alist `(("." . "~/emacsBackupFiles")))
  
  (setq delete-old-versions t
    kept-new-versions 1
    kept-old-versions 1
    version-control t)
  
  ;; This will turn off all backup files.
  ;; (setq make-backup-files nil)
  
  
  
  
  
  

  
  
  
  
  
  

  ---

  vi editor
  

  I used emacs until I went into IDE's. Now that I am back to some linux programming, here are some tips for those times when I do a bit of VI (like when you are running as root and need an editor for a config file).

  • Run vi - "vi fileName"

  • Enter insert mode - Type "i <RET>". Now any further text you type is entered into the file as data. You can use the arrow keys to move around the file. This command leaves command mode.

  • Leave insert mode - Type the <ESC> key. Now you are back in command mode.

  • Save changes and exit vi - ":wq <RET>" Type this in command mode

  • Exit vi withOUT saving changes - ":q! <RET>" Type this in command mode

  • Search for the next occurrence after the cursor of some pattern - "/pattern <RET>" Type this in command mode

  • Search for the previous occurrence after the cursor of some pattern - "?pattern <RET>" Type this in command mode

  • Find the next occurrence of the pattern - "n <RET>" Type this in command mode

  • Save the current file - ":w <RET>" Type this in command mode

  • Save the current file to a new file - ":w fileName <RET>" Type this in command mode
  
  
  

  ---

  Emacs Common Things
  

  For some reason, I always forget these things.

  • Conditional-Search-Replace M-% string RET newstring RET
    Then, <Space> to replace the current instance, <DEL> to skip the current instance, <RET> to stop search without any more replacements
  
  
  

  ---

  Installing and configuring Apache
  See https://fedoraproject.org/wiki/Apache_HTTP_Server
  • Install Apache
    • su
    • dnf install httpd
    • To have the server start at each boot: systemctl enable httpd.service
    • To start the server now: systemctl start httpd.service
  • Configuration
    • GUI Configuration tool: /usr/bin/system-config-httpd
    • Manual edit config files. emacs /etc/httpd/conf/httpd.conf
  
  
  

  ---

  Using CSS "position" attributes for HTML Layout
  
  
  

  Many HTML elements may use CSS to control where they are positioned on a page. This is done with a "position" attribute, that may have two values: "absolute" or "relative". For example:

  • style="position:absolute; left:0px; top:0px;"
  • style="position:relative; left:0px; top:0px;"

  These can be confusing, because they use the terms "absolute" and "relative" to place an element in a position in relation to the "normal position of that element in the HTML layout", and NOT necessarily in relation to another element. So, the browser first lays out an HTML document, which assigns every element in the document to a position on the page. This initial position is referred to as the element's position in the "document flow". Once the browser has completed this initial layout step, then the CSS position attributes may override each element's position and place the element in a different place.

  "Relative" means place the element at some offset in relation to where it would normally go in the HTML laytout. So, for example, if a typical HTML page would place an element at x=100,y=200, and the element had an attribute

  • style="position:relative; left:50px; top:75px;"
  then the element would be placed at x=150,y=275.

  "Absolute" means place the element at some "absolute" position, and just ignore where it would normally go in the HTML laytout. So, for example, if a typical HTML page would place an element at x=100,y=200, and the element had an attribute

  • style="position:absolute; left:50px; top:75px;"
  then the element would be placed at x=50,y=75.

  However, the confusing part is that an "absolute" coordinate is still in relation to somethng. It may be in relation to the bottom-left corner of the HTML page, but it may also be in relation to a containing element, like a div element. So, "position:absolute" means an absolute position compared to the flow of the document but still relative to the position of the parent HTML element that contains the element being moved.

Raspberry Pi

Install the Raspberry Pi Imager (on Linux)

• sudo -i
• dnf install rpi-imager

Install Raspberry Pi OS on a microSD card

• Run lsblk to see which devices are NOT the SD card. This will print a list of devices.
• Plug an SD card into the linux box - I use a USB-SD-reader.
• Run "lsblk" again. The USB HDMI is cometimes sdb, but beware. That can differ with different devices.
• rpi-imager
  • For Pi-Hold I install Raspberry-Pi OS Lite (32 bit)
• Now, eject the microSD card
• Insert SD card into Pi, connect a monitor and keyboard and power on
• Power on the Raspberry Pi and connect to it through a keyboard and monitor
• Create a new username and password
• sudo systemctl enable ssh
• sudo systemctl start ssh
• Run "sudo raspi-config"
• Select "Interfacing Options"
• Select "SSH"
• Choose "Yes" and then "OK" and then "Finish"
• Run "hostname -I" to get the local IP-address. Note, must be uppercase "I". Lowercase "i" will work but return a meaningless IP address.
• Power down, move Raspberry Pi to its final location, connect to network, and power on

Pi-Hole

• SSH into the Pi with "ssh @"
• Run "curl -sSL https://install.pi-hole.net | bash"
  • Specify the static IP address. Assign an IP below your DHCP range (usually below 192.168.1.100)
  • Write Down the IP address and admin password
• Use local DNS to point to the pi-hole

Pi-Hole references:

• https://pi-hole.net/
• Install Video
• Block List

Copying Files from Linux to a Pi

• To copy from Linux to Pi: scp file.txt @xxx.xxx.xxx.xxx:destinationDir/
• To copy from Pi to Linux: scp file.txt @xxx.xxx.xxx.xxx: