Mysql command line password with special characters is not working - mysql

Question

I've the following bash script to upgrade my database schema. Script reads hostname and database password from command line.
The problem is here that if the password is alphanumeric e.g r00t then script works. But if password contains special characters e.g pa**w0rd, then script does not work and directly exits. Please help me with this. Thanks.
#!/bin/bash
echo "Enter hostname."
read -p "Hostname [localhost]: " DB_HOST
DB_HOST=${DB_HOST:-localhost}
echo "Enter MySQL root password"
DB_PASS=
while [[ $DB_PASS = "" ]]; do
read -sp "Password: " DB_PASS
done
MYSQL="mysql --force --connect-timeout=90 --host=$DB_HOST -u root --password=${DB_PASS}"
# Apply schema updates. My DBName is "mydb"
# Upgrade schema file is stored in "mysql" folder
$MYSQL mydb -e exit > /dev/null 2>&1 && $MYSQL mydb < "../mysql/upgrade_schema_v.2.1.sql"

Answer 1

Logging into mysql using bash
For ubuntu or linux shell try to use command
mysql -u username -p'p#ssw()rD'
for remote host login use
mysql -h hostname -u user -p'password'

Answer 2

This is occurring because you are using shell GLOB (wildcard) characters in the password, and in Bash (or on Linux generally) wildcards are expanded by the shell.
The safest and most reliable solution is to not use shell wildcard characters or other characters interpreted by the shell in the password. You should also avoid spaces. There are plenty of other characters.
Here are the ones you should avoid:
" ' $ , [ ] * ? { } ~ # % \ < > | ^ ;
Here are the ones it is usually safe to use:
: # . , / + - ! =
To ensure the password is still secure, make it longer. As an example:
K#3amvv7l1wz1192sjqhym
This meets old-fashioned password complexity rules, because upper, lower, numbers and special characters are in the first four, the remainder is randomly generated but avoids any problematic characters.
However if you must use them, you can quote the password parameter with single quotes - though you will still run in to trouble if the password contains single quotes!

Answer 3

Try enclosing your password in single quotes.
If it's pa**w0rd, use 'pa**w0rd'

Answer 4

Variables are best used for data, not code. The layers of variables make it hard to protect the expansion when you want some parts of the expansion (i.e., you want your command line to be word split on the tokens you want), but don't want all the other effects. The solution is to not store the code in a string. Instead, use a function like:
do_mysql() {
host="$1"
pass="$2"
mysql --force --connect-timeout=90 --host="$host" -u root --password="$pass" "$#"
}
then you can run it with extra arguments like
do_mysql "$DB_HOST" "$DB_PASS" -e exit > /dev/null && do_mysql "$DB_HOST" "$DB_PASS" < "../mysql/upgrade_schema_v.2.1.sql"
Though it would also be better not to use upper case for your variables. Doing so makes it so you could collide with environment variables and accidentally change things you don't intend to change (as the number of people who accidentally reset PATH can attest).