Change java version on Mac

To see which version of java is installed, do;

java -version

with an example of the output being;

java version "17.0.4" 2022-07-19 LTS

Java(TM) SE Runtime Environment (build 17.0.4+11-LTS-179)

Java HotSpot(TM) 64-Bit Server VM (build 17.0.4+11-LTS-179, mixed mode, sharing)

If we want to change the default version, first do;

/usr/libexec/java_home -V

an example of the output is;

Matching Java Virtual Machines (2):

    17.0.4 (x86_64) "Oracle Corporation" - "Java SE 17.0.4" /Library/Java/JavaVirtualMachines/jdk-17.0.4.jdk/Contents/Home

    11.0.15.1 (x86_64) "Oracle Corporation" - "Java SE 11.0.15.1" /Library/Java/JavaVirtualMachines/jdk-11.0.15.1.jdk/Contents/Home

/Library/Java/JavaVirtualMachines/jdk-17.0.4.jdk/Contents/Home

then if we wanted to change it, we would do;

export JAVA_HOME='/usr/libexec/java_home -v 11.015.1'

The above is untested.

NCURSES

 TBC

https://tldp.org/HOWTO/NCURSES-Programming-HOWTO/index.html 

MySQL create a new user

CREATE USER 'username'@'%' IDENTIFIED BY 'password';

GRANT privilege ON database.table TO 'username'@'%';

The above can be combined into one as;

GRANT privilege ON database.table TO 'username'@'%' IDENTIFIED BY 'password';

To grant basic permissions on a specific database or table. for example;

CREATE USER 'username'@'%' IDENTIFIED BY 'password';

GRANT EXECUTE ON database.* TO 'username'@'%';

which would allow the username to run procedures in the specified database and nothing else.

The following may also be of use;

GRANT ALL PRIVILEGES ON *.* TO  'username'@'%' IDENTIFIED BY 'password';

GRANT GRANT OPTION ON *.* TO  'username'@'%';

Create iso file from file on a Mac

1) Open Disk Utility and choose FILE > NEW IMAGE > IMAGE FROM FOLDER

2) Choose the folder and select IMAGE FORMAT as DVD/CD Master.

3) Navigate to where the file is created and run the following command;

hdiutil makehybrid -iso -joliet -o LIC.iso LIC.cdr

where LIC.iso is the TARGET and LIC.cdr is the SOURCE.

On Linux we would use;

mkisofs -o LIC.iso /path/to/LIC

where LIC.iso is the TARGET and LIC is the SOURCE folder.

If we have a cdrom as a source, we could use;

dd if=/dev/cdrom of=/path/to/LIC.iso

Alpha and OpenVMS

To return to the default directory, do;

SET DEF DFCROOT:[000000]

or SET DEF [-] 

DIR *.DIR

Shows all sub directories.

DIR /SIZE/DATE

Shows file size and date attributes.

 

To change to a directory normally do;

SET DEF [dir_name] or [dir_name.sub_dir_name]

where a directory is denoted by a .DIR extension.

Random stuff;

@SYS$UPDATE:VMSLICENSE.COM

See also here

To configure TCPIP, do @TCPIP$CONFIG

To start networking at boot time, add the following to STARTUP_VMS.COM by doing EDIT STARTUP_VMS.COM

@SYS$STARTUP:TCPIP$STARTUP

A note on the Alpha, TCPIP PING doesn't seem to work, however see UCX HELP

DELETE FILE.EXT;5

Deletes FILE.EXT version 5

PURGE /KEEP=100 FILE.EXT

Deletes FILE.EXT, keeping the 100 latest versions of the file.

 

To INITIALIZE a DISK;

INITIALIZE HN1$DKA100 DATA

where the output of SHOW DEVICE shows HN1$DKA100 UNDER Name.

Afterwords, we can mount the disk as;

MOUNT DKA100 DATA where DATA is the label

To mount a CDROM showing as DKA100, use;

MOUNT /override=ident DKA100

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