Search found 175 matches

by chris
Fri Feb 12, 2021 7:10 pm
Forum: General
Topic: linux repeat command x times
Replies: 1
Views: 47

Re: linux repeat command x times

With the up arrow you get the last commands you typed, and press enter to execute it. If you want to run the same command several times, you can use for-loop ( in bash) for n in {1..3}; do <COMMAND>; done repeats 3 times Another option is watch If you want to repeat a command every x seconds, ideal ...
by chris
Sun Feb 07, 2021 7:48 am
Forum: SQL
Topic: mysql update add to text
Replies: 1
Views: 53

Re: mysql update add to text

you can use concat to add to already existing string (varchar,text,...)

Code: Select all

UPDATE table_name SET text_field=CONCAT(text_field,'string to add') WHERE  id='1';
It doesn't work if the value is NULL,
It works with an empty string ('').
So you should replace all NULL values with empty string before.
by chris
Wed Sep 23, 2020 4:01 pm
Forum: Shell
Topic: switch in bash
Replies: 1
Views: 851

Re: switch in bash

Yes, it look lik this:

Code: Select all

#Set the IP
case $VALUE in
1)
IP=192.168.1.160
NAME='a';
;;
2)
IP=192.168.1.161
NAME='B';
;;
*)
IP=192.168.1.1
NAME='Default';
;;
esac
in this case $VALUE can be 1 or 2,
anything else will result in default.
I think it is a string compare, so you can use anything.
by chris
Sat Sep 19, 2020 2:46 pm
Forum: Shell
Topic: Bash last char of a string
Replies: 2
Views: 27439

Re: Bash last char of a string

you can also use:

Code: Select all

echo ${STRING: -1}
Just remember that the last character can sometimes be a whitespace ( space, newline ...)
by chris
Tue Sep 08, 2020 1:43 pm
Forum: SQL
Topic: Join 1 table on 2 different tables
Replies: 1
Views: 975

Re: Join 1 table on 2 different tables

You can work with a sub-query an UNION:

Code: Select all

SELECT table1.id,union_table.name FROM table1 LEFT JOIN 
   (SELECT id,name FROM table2 UNION SELECT id,title AS name FROM table3) 
   AS union_table ON table1.other_id=union_table.id;
by chris
Thu Apr 23, 2020 6:59 am
Forum: SQL
Topic: Solved: Incorrect date value: '0000-00-00' for column
Replies: 2
Views: 1773

Re: Incorrect date value: '0000-00-00' for column

The error is because MYSQL is in strict mode (default) You can Check MYSQL mode SELECT @@GLOBAL.sql_mode global, @@SESSION.sql_mode session You change it with the following query; SET sql_mode = ''; or SET GLOBAL sql_mode = ''; Using the keyword GLOBAL requires super privileges and it affects the op...
by chris
Mon Mar 30, 2020 8:14 pm
Forum: Servers
Topic: Linux startup script
Replies: 1
Views: 1623

Re: Linux startup script

There are several ways to run a script on startup/reboot on linux. My favorite : Crontab sudo crontab -e @reboot /home/me/scripts/this.sh Another way to do it, local.d scripts at boot time, add its init.d script to the default runlevel. Enable local.d Scripts rc-service local start and then create y...
by chris
Fri Mar 20, 2020 9:23 pm
Forum: MySQL
Topic: php mysqli_connect: authentication method unknown to the client [caching_sha2_password]
Replies: 1
Views: 1537

Re: php mysqli_connect: authentication method unknown to the client [caching_sha2_password]

MYSQL has changed it type of password (since Mysql 8 ?)
Anyway the easiest solution, is execute the following SQL command on MYSQL

Code: Select all

ALTER USER 'mysqlUsername'@'localhost' IDENTIFIED WITH mysql_native_password BY 'mysqlUsernamePassword';
It should solve your problem.
by chris
Sun Feb 16, 2020 9:02 pm
Forum: Postfix
Topic: postfix not mail from other hosts
Replies: 4
Views: 2858

Re: postfix not mail from other hosts

Are you sure you are sending it to the right account?

sometimes you need to also add the domain name (even if it is not a public domain).

Code: Select all

sendmail user@host.domain.com
by chris
Sun Feb 16, 2020 1:10 pm
Forum: Postfix
Topic: postfix not mail from other hosts
Replies: 4
Views: 2858

Re: postfix not mail from other hosts

are you sending to a user on the server.
Do a test from the client:

Code: Select all

sendmail user@host
and check the logs on the client and on the server.