Appendix E. Environment Variables

This appendix lists all the environment variables that are used directly or indirectly by MySQL. Most of these can also be found in other places in this manual.

Note that any options on the command line take precedence over values specified in option files and environment variables, and values in option files take precedence over values in environment variables.

In many cases, it's preferable to use an option file instead of environment variables to modify the behavior of MySQL. See the section called “Using Option Files”.

VariableDescription
CXXThe name of your C++ compiler (for running configure).
CCThe name of your C compiler (for running configure).
CFLAGSFlags for your C compiler (for running configure).
CXXFLAGSFlags for your C++ compiler (for running configure).
DBI_USERThe default username for Perl DBI.
DBI_TRACETrace options for Perl DBI.
HOMEThe default path for the mysql history file is $HOME/.mysql_history.
LD_RUN_PATHUsed to specify where your libmysqlclient.so is located.
MYSQL_DEBUGDebug trace options when debugging.
MYSQL_HISTFILEThe path to the mysql history file. If this variable is set, its value overrides the default of $HOME/.mysql_history.
MYSQL_HOSTThe default hostname used by the mysql command-line client.
MYSQL_PS1The command prompt to use in the mysql command-line client.
MYSQL_PWDThe default password when connecting to mysqld. Note that use of this is insecure! See the section called “Keeping Your Password Secure”.
MYSQL_TCP_PORTThe default TCP/IP port number.
MYSQL_UNIX_PORTThe default Unix socket filename; used for connections to localhost.
PATHUsed by the shell to find MySQL programs.
TMPDIRThe directory where temporary files are created.
TZThis should be set to your local time zone. See the section called “Time Zone Problems”.
UMASK_DIRThe user-directory creation mask when creating directories. Note that this is ANDed with UMASK!
UMASKThe user-file creation mask when creating files.
USERThe default username on Windows and NetWare to use when connecting to mysqld.