Mac OS Tips

Dark mode in Safari make a CSS text file using the CSS code below copy/paste into TextEdit. In TextEdit choose View | Make Plain Text then save it calling it like SafariDarkMode.css and save it to your documents folder.

color (text is silver), background-color and background are night black. Notice that background doesn't have !important tag otherwise it'll block out many elements.  a:link is purple,  a:visited is red a:hover is pink. Change the hex colors as you wish.

* { color: #BCC6CC !important; background-color: #0C090A !important; background: #0C090A; }

a:link { color: #7A5DC7 !important; }

a:visited { color: #CA226B !important; }

a:hover { color: #C48793 !important; }

img { filter: grayscale(40%); }

Reduce files of PDFs by a huge margin while maintaining acceptable image quality

use EXFAT for writing Windows/Mac although it'll have fork resources and creates hidden files so to get rid of those you can use a free utility CleanMyDrive2

If you download an app and attempt to install the dmg you might get a warning. Settings / Security & Privacy click Open Anyway.

Turn on File Sharing in Settings even if not using SMB (Samba) to share any files.  Enables the NetBios name to be used.  So if using as a server the clients just need to type in the macmini.local rather than the IP. 

Settings / Network / WiFi / Advanced / TCP/IP Setting a static rather than dynamic IP is ideal if using as a server. However choosing Using DHCP with manual address doesn't work for me as it sets the Subnet Mask to 255.255.255.255 instead of 255.255.255.0 so instead I choose Manually set the Subnet Mask, Router, and DNS servers.  Can find all this info from any client like your phone under WiFi info.

Settings / Spotlight and prevent it from indexing and searching external harddrives.

Screen Capturing

cmd + shift + 3 = captures whole screen
cmd + shift + 4 = captures selected region
cmd + shift + 4 + spacebar = captures window with camera icon

Use Preview as an image and PDF viewer. Basic image editing functions are Tools - Crop, Adjust Size to make the dimensions smaller, Export as jpg to reduce file size.

Keka is a free compression software for zip and other formats.  It has one huge time saving feature (Archive items separately) in case you need to batch zip up hundreds of folders and each folder zip of separately.  Useful to take directories of photos and zip them up individually then move those .zip into Komga book / comic book server.

10.0.0.0 - 10.255.255.255 (16,777,214 hosts per Class A network)
172.16.0.0 - 172.31.255.255 (65,534 hosts per Class B network)
192.168.0.0 - 192.168.255.255 (254 hosts per Class C network) 

netmask | bits | Subnet
~~~~~~~~~~~~~~~~|~~~~|~~~~~~~~~~~~~~~
255.0.0.0 | /8 | Class A
255.255.0.0 | /16 | Class B
255.255.255.0 |/ 24 | Class C
255.255.255.255 |/ 32 | Point-to-point
________________________________________________________________

1 kilobyte = 2^10 Bytes = 1024 bytes = .98 Kibibyte
1 MB Megabyte = 2^20 Bytes = 1024 kilobytes = .95 MiB Mebibyte
1 GB gigabyte = 2^30 Bytes = 1024 Megabytes = .93 GiB Gibibyte
1 TB terabyte = 2^40 Bytes = 1024 gigabytes = .91 TiB Tebibyte
1 PB petabyte = 2^50 Bytes = 1024 terabytes = .89 PiB Pebibyte
1 EB Exabyte = 2^60 Bytes = 1024 petabytes = .87 EiB Exbibyte
1 ZB Zettabyte = 2^70 Bytes = 1024 Exabytes = .85 Zebibyte
1 YB Yottabyte = 2^80 Bytes = 1024 Zettabytes = .83 Yobibyte

Command Lines in Terminal 

triple click = to select a sentence
CMD + delete = to delete from entire line left of cursor
OPTION + delete = to delete one word
cmd + click = same as right clicking mouse

cmd + TAB = cycle through apps
cmd + M  = minimize
cmd + H = hide window
cmd + W = close window
cmd + Q = quit application
cmd + Option + ESC = force quit apps

Finder
cmd + N = new Finder window
select file, press ENTER = to rename file

Arrow Keys
cmd + left = beginning of line
cmd + right = end of line

cmd + C = copy
cmd + V = paste
cmd + X = cut
cmd + A = select all
cmd + Z = undo
cmd + Z + shift = redo

Terminal BASH
must use CTRL-E end of line, CTRL-A beginning of line

Booting up Mac
Hold Option key to startup in Target Disk Mode or in settings select Target Disk

diskutil list (shows current Volumes)

To get the size of all directories in the current directory: maxdepth = # recursive subfolders

find . -maxdepth 1 -type d -print | xargs du -skh | sort -rn
find . -maxdepth 2 -type d -print | xargs du -skh | sort -rn

To download a linux iso using curl
curl -o linux.iso https://www.membo.webnode.com/linux.iso

To resume a partially download file using or curl
curl -C - -o linux.iso -e https://membo.webnode.com https://membo.webnode.com/linux.iso

To resume a partially download file via ftp with username and password using curl
curl -C - -u username:password -o linux.iso ftp.membo.webnode.com/linux.iso

56Kbps = 7KB/s (dial up 1995, DSL 1997)
64Kbps = 8KB/s (ISDN)
128Kbps = 16KB/s (ISDN)
512Kbps = 64KB/s
1024Kbps = 128KB/s
3G (1,000Kbps) = 125KB/s
1.5Mbps = 188KB/s (some DSL & T1)
6Mbps = 800KB/s (cable and DSL)
10Mbps = 1.3MB/s (cable)
25Mbps = 3MB/s (cable)
50Mbps = 6MB/s (cable)
100Mbps = 12MB/s (fiber, 10/100Mbps ethernet)
1000Mbps = 120MB/s (if all switches, routers are gigabit ethernet)

USB 2.0 = 57MB/s
WiFi 802.11b = 1.4MB/s
WiFi 802.11g = 6.8MB/s
WiFi 802.11n = 31MB/s

Time to copy 10GB bluray to NAS
unrar on the fly 7MB/s = 24 mins
10/100 ethernet 12MB/s = 14 mins
7200rpm 21MB/s = 8 mins