How to change the transparency of text in the Mac preview

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This text is the watermark that I want to add. I was just wondering how to change its transparency.

Command line – Opening MPI interrupted after upgrading to Mac OS X 10.14.6

After upgrading to 10.14.6, openmpi no longer works on my MacBook Air (2019). Try to execute related commands mpicxx or mpiexec produce the error

    dyld: Library not loaded: /usr/local/opt/libevent/lib/libevent-2.1.6.dylib

I have reinstalled the latest versions of openmpi (4.0.1) and libevent (2.1.11) (this was not necessary in the previous openmpi the installation but openmpi could not make without this). However, even if the installation of openmpi succeeded, it always seems to be corrupted and fails with the same error as above during the execution mpiexec.

Do you have any ideas about the cause of this problem or how to make it work again?

The iPhone does not vibrate when message notifications are disabled on Mac

When I disable notifications for messages on macOS, I do not get vibration from my iPhone on incoming texts when I use my Mac at the same time. It always sends them in silence, provided that I saw the message on my Mac.

Is there a way to fix this?

DHCP – Assign IPv6 based on the MAC address?

The block that is assigned is 2001: 41d0: 8: 7d1 :: / 64 gateway 2001: 41d0: 8: 7ff: ff: ff: ff: ff (OVH IP)

For some reason, DHCP already automatically assigns IPv6 even before adding anything (fe80 :: ff: fed2: 9128/64)


auto lo
iface lo inet loopback

iface eno1 inet manual

auto vmbr0
iface vmbr0 inet static
        netmask  24
        bridge-ports eno1
        bridge-stp off
        bridge-fd 0

iface vmbr0 inet6 static
        address 2001:41d0:8:7d1::1
        netmask 64
        post-up /sbin/ip -f inet6 route add 2001:41d0:8:7ff:ff:ff:ff:ff dev vmbr0
        post-up /sbin/ip -f inet6 route add default via 2001:41d0:8:7ff:ff:ff:ff:ff
        pre-down /sbin/ip -f inet6 route del default via 2001:41d0:8:7ff:ff:ff:ff:ff200
        pre-down /sbin/ip -f inet6 route del 2001:41d0:8:7ff:ff:ff:ff:ff dev vmbr0


# Defaults for isc-dhcp-server (sourced by /etc/init.d/isc-dhcp-server)

# Path to dhcpd's config file (default: /etc/dhcp/dhcpd.conf).

# Path to dhcpd's PID file (default: /var/run/

# Additional options to start dhcpd with.
#       Don't use options -cf or -pf here; use DHCPD_CONF/ DHCPD_PID instead

# On what interfaces should the DHCP server (dhcpd) serve DHCP requests?
#       Separate multiple interfaces with spaces, e.g. "eth0 eth1".


ddns-update-style none;
default-lease-time 600;
max-lease-time 7200;
log-facility local7;
option rfc3442-classless-static-routes code 121 = array of integer 8;
option ms-classless-static-routes code 249 = array of integer 8;

subnet netmask {
 default-lease-time 21600000;
 max-lease-time 432000000;
 option routers;
 option domain-name-servers,;
 option rfc3442-classless-static-routes 32, 176, 31, 246, 254, 0, 0, 0, 0, 0, 176, 31, 246, 254;
 option ms-classless-static-routes 32, 176, 31, 246, 254, 0, 0, 0, 0, 0, 176, 31, 246, 254;
  host 1 {hardware ethernet 02:00:00:d2:91:28;fixed-address;option subnet-mask;option routers;}
  host 2 {hardware ethernet 02:00:00:59:9f:96;fixed-address;option subnet-mask;option routers;}
  host 3 {hardware ethernet 02:00:00:b4:92:6e;fixed-address;option subnet-mask;option routers;}
  host 4 {hardware ethernet 02:00:00:9e:f6:3e;fixed-address;option subnet-mask;option routers;}


# The ddns-updates-style parameter controls whether or not the server will
# attempt to do a DNS update when a lease is confirmed.
ddns-update-style none;

# Option definitions common to all supported networks...
default-lease-time 600;
max-lease-time 7200;

# This DHCP server is the official DHCP server for the local network

# Use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).
log-facility local7;

# Subnet declaration
host1 {hardware ethernet 02:00:00:59:9f:96;fixed-address6 2001:41d0:8:7d1:8888:9999:0000:2222;option dhcp6.domain-search "netprobe.local";}

Opening of pdf on ssh in a Mac terminal

As the title says, I do it

> ssh 
> cd documents/ 
> okular example.pdf 
QXcbConnection: Could not connect to display 
Aborted (core dumped)

I connect to an OpenSUSE machine via SSH from a Mac operating system.

How to resize MP4 videos using the command line on a mac terminal?

I try to write scripts that automatically resize photos and videos to specific sizes / percentages of the original.

However, I have not found a solution for the videos. Ideas?

The Mac OS X Snow Leopard virtual machine is constantly rebooting

When I was trying to run Mac OS X Snow Leopard on VMware, everything went well until I reached the loading bar with the chameleon at the top. The loading bar would come down completely, and then the virtual machine would reboot.

After rebooting, the load bar would come down completely to restart again. It was an endless loop. I do not know what I did wrong. Anyone could explain me how to solve this problem.

Chameleon loading screen

macos – Mac OS does not open a file if the application is open – Need to quit the application each time to open files

  • Mac user long time ago but never had this problem before and it drives me crazy.

Whenever I open a file by double-clicking it, it refuses to open it if the application is already open. Oddly, the fast flash icon that you see when you open a file opens, but does not load.

I will have to leave the application and then reopen the file for it to open. Then once in the application, I can select Open from the drop-down menu that works.

This occurs on all types of applications, not just one, Photoshop, Excel, Word, Preview, Quicktime, and so on.

I then tried to show this to a friend and this completely stopped happening for a few hours (Sods law) at this time! It seems that, momentarily, it starts to work again.

How could I solve this strange behavior?

How to write a hundred symbol on a Mac keyboard? – Everything else

To do this, you need to find a virtual keyboard on the MacBook, here In this article you will find a description of how to proceed quickly. There you will find many special characters, including the hundred symbol. I hope this helps you.