Is it possible to remove the prompt history on MariaDB? - mariadb

Question

The main problem is that I wrote a security sensitive statement on MariaDB (among many other statements), so I would like to remove the prompt history (like the command history -c on Linux):
jordiba90#lts:~$ sudo mariadb -u root -p
[sudo] contraseña para jordiba90:
Enter password:
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 36
Server version: 10.3.25-MariaDB-0ubuntu0.20.04.1 Ubuntu 20.04
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [(none)]> USE mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
MariaDB [mysql]> UPDATE user SET password=PASSWORD("PASSWORD") WHERE user="root";
Query OK, 0 rows affected (0.001 sec)
Rows matched: 1 Changed: 0 Warnings: 0
MariaDB [mysql]> FLUSH privileges;
Query OK, 0 rows affected (0.001 sec)
So, when I click the up&down buttons on my keyboard I see all the prompt history.
When I try to remove the prompt history on MariaDB, it does not work:
MariaDB [(none)]> clear
MariaDB [(none)]> \c
MariaDB [(none)]> quit
Bye
So, I have checked on the internet this script (that does not work either):
jordiba90#lts:~$ rm ~/.mysql_history
jordiba90#lts:~$ export MYSQL_HISTFILE=/dev/null
jordiba90#lts:~$ set | grep MYSQ
MYSQL_HISTFILE=/dev/null
_=MYSQL_HISTFILE=/dev/null
REFERENCE > https://www.thegeekstuff.com/2010/01/disable-mysql-history-clear-mysql_history-and-mysql_histfile/
After that, I have also checked on the internet another script (that does not work either, again):
jordiba90#lts:~$ ~/.mysql_history
bash: /home/jordiba90/.mysql_history: No existe el archivo o el directorio
jordiba90#lts:~$ rm $HOME/.mysql_history
rm: no se puede borrar '/home/jordiba90/.mysql_history': No existe el archivo o el directorio
jordiba90#lts:~$ ln -s /dev/null $HOME/.mysql_history
REFERENCE > https://www.cyberciti.biz/faq/howto-clear-mysql-command-history/
One the one hand, there are too many files on my OS related to "mysql" but none related to mysql history, so I have checked one by one all the files related to mysql configuration and I did not find the one I should remove:
jordiba90#lts:~$ locate mysql | wc
421 421 25918
jordiba90#lts:~$ locate mysql | grep history
jordiba90#lts:~$ locate mysql | grep conf
/etc/mysql/conf.d
/etc/mysql/conf.d/mysql.cnf
/etc/mysql/conf.d/mysqldump.cnf
/etc/mysql/mariadb.conf.d
/etc/mysql/mariadb.conf.d/50-client.cnf
/etc/mysql/mariadb.conf.d/50-mysql-clients.cnf
/etc/mysql/mariadb.conf.d/50-mysqld_safe.cnf
/etc/mysql/mariadb.conf.d/50-server.cnf
/usr/share/mysql-common/configure-symlinks
/usr/share/mysql/systemd/use_galera_new_cluster.conf
/var/lib/dpkg/info/mysql-common.conffiles
One the other hand, the same happens with the mariadb files:
jordiba90#lts:~$ locate mariadb | wc
101 101 5042
jordiba90#lts:~$ locate mariadb | grep history
jordiba90#lts:~$ locate mariadb | grep conf
/etc/insserv.conf.d/mariadb
/etc/mysql/mariadb.conf.d
/etc/mysql/mariadb.conf.d/50-client.cnf
/etc/mysql/mariadb.conf.d/50-mysql-clients.cnf
/etc/mysql/mariadb.conf.d/50-mysqld_safe.cnf
/etc/mysql/mariadb.conf.d/50-server.cnf
/usr/lib/systemd/system/mariadb#bootstrap.service.d/use_galera_new_cluster.conf
/var/lib/dpkg/info/mariadb-client-10.3.conffiles
/var/lib/dpkg/info/mariadb-common.conffiles
/var/lib/dpkg/info/mariadb-server-10.3.conffiles
/var/lib/dpkg/info/mariadb-server-10.3.config
Could you please give me a hint? You can check that I have tried it. Thanks in advance.
PS_1: if there is any other entry about this topic on Stack* (I have checked it and I did not see one) or if my entry breaks any rule on Stack* (I have checked the rules and I think I do not break any), please send me a PM and I will delete this entry. I am trying to learn without losing reputation points for asking a question.
PS_2: I have restarted mysql and right now the status is active (running):
jordiba90#lts:~$ sudo /etc/init.d/mysql restart
Restarting mysql (via systemctl): mysql.service.
jordiba90#lts:~$ sudo /etc/init.d/mysql status
● mariadb.service - MariaDB 10.3.25 database server
Loaded: loaded (/lib/systemd/system/mariadb.service; enabled; vendor preset: enabled)
Active: active (running) since Sat 2020-11-14 13:24:47 CET; 8h ago
Docs: man:mysqld(8)
https://mariadb.com/kb/en/library/systemd/
Process: 826 ExecStartPre=/usr/bin/install -m 755 -o mysql -g root -d /var/run/mysqld (code=exited, status=0/SUCCESS)
Process: 861 ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
Process: 876 ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] && VAR= || VAR=`cd /usr/bin/..; /usr/bin/galera_recovery`; [ $? -eq 0 ] && systemctl set-environment _WSREP_START_POSITION=$VAR || exit 1 (code=exited, status=0/SUCCESS)
Process: 1026 ExecStartPost=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
Process: 1028 ExecStartPost=/etc/mysql/debian-start (code=exited, status=0/SUCCESS)
Main PID: 957 (mysqld)
Status: "Taking your SQL requests now..."
Tasks: 31 (limit: 9423)
Memory: 93.1M
CGroup: /system.slice/mariadb.service
└─957 /usr/sbin/mysqld
nov 14 13:24:46 lts systemd[1]: Starting MariaDB 10.3.25 database server...
nov 14 13:24:47 lts mysqld[957]: 2020-11-14 13:24:47 0 [Note] /usr/sbin/mysqld (mysqld 10.3.25-MariaDB-0ubuntu0.20.04.1) starting as…ess 957 ...
nov 14 13:24:47 lts mysqld[957]: 2020-11-14 13:24:47 0 [Warning] Could not increase number of max_open_files to more than 16384 (request: 32186)
nov 14 13:24:47 lts systemd[1]: Started MariaDB 10.3.25 database server.
nov 14 13:24:47 lts /etc/mysql/debian-start[1030]: Upgrading MySQL tables if necessary.
nov 14 13:24:47 lts /etc/mysql/debian-start[1033]: Looking for 'mysql' as: /usr/bin/mysql
nov 14 13:24:47 lts /etc/mysql/debian-start[1033]: Looking for 'mysqlcheck' as: /usr/bin/mysqlcheck
nov 14 13:24:47 lts /etc/mysql/debian-start[1033]: This installation of MySQL is already upgraded to 10.3.25-MariaDB, use --force if y…l_upgrade
Hint: Some lines were ellipsized, use -l to show in full.
REFERENCE > https://superuser.com/questions/282115/how-to-restart-mysql
PS_3: I have tried the command stat ~/.mysql_history; rm ~/.mysql_history; stat ~/.mysql_history and the output that I have is that the file or the directory /home/jordiba90/.mysql_history does not exist
PS_4: I have tried the command strace mysql and I can not share here the output because there is a message body limit to 30.000 characters (and if I do that, I should have entered 44.321, aprox)
PS_5: Having checked the specific output openat(AT_FDCWD..., there is none related to mysql_history. It does not appear that specific sentence
PS_6: I have used 'sudo' to try the command 'strace mysql'and I have got the following output related to mysql history:
openat(AT_FDCWD, "/root/.mysql_history", O_RDONLY) = 4
fstat(4, {st_mode=S_IFREG|0600, st_size=4585, ...}) = 0
read(4, "misql -u root -p\nDatascience2005"..., 4585) = 4585
close(4) = 0
write(1, "\33(B\33[m\33(B\33[0;1mType 'help;' or '"..., 94Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
) = 94
write(1, "\n", 1
)
PS_7: I have removed the last directory related to mysql history named /root/.mysql_history but I still see the history on the mariadb prompt

Answer 1

Editing the history file (for example with vim, and deleting the problematic lines) worked in my case:
vim ~/.mysql_history
(mysql Ver 15.1 Distrib 10.4.14-MariaDB)

Answer 2

Depending on how you are set up, you'll probably find it is located at root. I had the same on a new secured install of MariaDB on Ubuntu 22.04. Mine was located at /root/.mysql_history
I found it the usual way by using the excellent locate command (remember to use the updatedb command to update the database of any new files that have been added) and searching for mysql_history:
locate -i mysql_history
Do this search at the bash (or whatever you are using) command prompt as you are searching for a file in the file system, not in the MariaDB or MySQL shell itself.
On this search, there is no actual need for the -i option as mysql_history is lowercase, but you never know!
Searching for history will also work but you'll get a few more hits.
Once you have found the file, you can use the editor of your choice to remove any sensitive command lines that may have found their way in there.