## 4.4 Installation-Related Programs 

user = unix_user4 

See Section 4.2.2.2, “Using Option Files” . 

The programs in this section are used when installing or upgrading MySQL. 

## 4.4.1 comp_err — Compile MySQL Error Message File 

comp_err  creates the errmsg.sys  file that is used by mysqld  to determine the error messages to display for different error codes. comp_err  normally is run automatically when MySQL is built. It compiles the errmsg.sys  file from text-format error information in MySQL source distributions: 

•As of MySQL 8.0.19, the error information comes from the messages_to_error_log.txt  and messages_to_clients.txt  files in the share  directory. 

For more information about defining error messages, see the comments within those files, along with the errmsg_readme.txt  file. 

•Prior to MySQL 8.0.19, the error information comes from the errmsg-utf8.txt  file in the sql/share directory. 

comp_err  also generates the mysqld_error.h , mysqld_ername.h , and mysqld_errmsg.h  header files. 

Invoke comp_err  like this: 

comp_err [ options ] 

comp_err  supports the following options. 

• --help , -? 

Display a help message and exit. 

• --charset= dir_name , -C dir_name 

The character set directory. The default is ../sql/share/charsets . 

• --debug= debug_options , -# debug_options 

Write a debugging log. A typical debug_options  string is d:t:O, file_name . The default is d:t:O,/ tmp/comp_err.trace . 

• --debug-info , -T 

Print some debugging information when the program exits. 

• --errmsg-file= file_name , -H file_name 

The name of the error message file. The default is mysqld_errmsg.h . This option was added in MySQL 8.0.18. 

• --header-file= file_name , -H file_name 

The name of the error header file. The default is mysqld_error.h . 

