MySQL安装脚本 mysql_install_db 详解

#!/bin/sh
# Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
# 
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

# This scripts creates the MySQL Server system tables
#
# All unrecognized arguments to this script are passed to mysqld.
#下面的是参数列表，有些是有默认参数值的
basedir=""
builddir=""
ldata="./data"
langdir=""
srcdir=""

args=""
defaults=""
mysqld_opt=""
user=""

force=0
in_rpm=0
ip_only=0
cross_bootstrap=0
#下面的usage函数是显示帮助提示信息的函数
usage()
{
  cat <&1`
  if test $? -ne 0
  then
    resolved=`$extra_bindir/resolveip localhost 2>&1`
    if test $? -ne 0
    then
      echo "Neither host '$hostname' nor 'localhost' could be looked up with"
      echo "$extra_bindir/resolveip"
      echo "Please configure the 'hostname' command to return a correct"
      echo "hostname."
      echo "If you want to solve this at a later stage, restart this script"
      echo "with the --force option"
      exit 1
    fi
    echo "WARNING: The host '$hostname' could not be looked up with resolveip."
    echo "This probably means that your libc libraries are not 100 % compatible"
    echo "with this binary MySQL version. The MySQL daemon, mysqld, should work"
    echo "normally with the exception that host name resolving will not work."
    echo "This means that you should use IP addresses instead of hostnames"
    echo "when specifying MySQL privileges !"
  fi
fi

if test "$ip_only" -eq 1
then
  hostname=`echo "$resolved" | awk '/ /{print $6}'`
fi

# Create database directories
for dir in $ldata $ldata/mysql $ldata/test
do
  if test ! -d $dir
  then
    mkdir -p $dir
    chmod 700 $dir
  fi
  if test -n "$user"
  then
    chown $user $dir
    if test $? -ne 0
    then
      echo "Cannot change ownership of the database directories to the '$user'"
      echo "user.  Check that you have the necessary permissions and try again."
      exit 1
    fi
  fi
done

if test -n "$user"
then
  args="$args --user=$user"
fi

# When doing a "cross bootstrap" install, no reference to the current
# host should be added to the system tables.  So we filter out any
# lines which contain the current host name.
if test $cross_bootstrap -eq 1
then
  filter_cmd_line="sed -e '/@current_hostname/d'"
else
  filter_cmd_line="cat"
fi

# Configure mysqld command line
mysqld_bootstrap="${MYSQLD_BOOTSTRAP-$mysqld}" #这里是将$mysqld变量的值给了$mysqld_bootstrap(注:$(xxxx-$mysqld)与$mysqld是一样的)
mysqld_install_cmd_line="$mysqld_bootstrap $defaults $mysqld_opt --bootstrap \
  --basedir=$basedir --datadir=$ldata --log-warnings=0 --loose-skip-innodb \
  --loose-skip-ndbcluster $args --max_allowed_packet=8M \
  --default-storage-engine=myisam \
  --net_buffer_length=16K"

# Create the system and help tables by passing them to "mysqld --bootstrap"
s_echo "Installing MySQL system tables..."
#下面if条件语句是安装数据库，他将$create_system_tables和$fill_system_tables两个角门对于的sql刷新到数据库mysql库中。
#如果执行成功会报OK，否则会报错
if { echo "use mysql;"; cat $create_system_tables $fill_system_tables; } | eval "$filter_cmd_line" | $mysqld_install_cmd_line > /dev/null
then
  s_echo "OK"
else
  echo
  echo "Installation of system tables failed!  Examine the logs in"
  echo "$ldata for more information."
  echo
  echo "You can try to start the mysqld daemon with:"
  echo
  echo "    shell> $mysqld --skip-grant &"
  echo
  echo "and use the command line tool $bindir/mysql"
  echo "to connect to the mysql database and look at the grant tables:"
  echo
  echo "    shell> $bindir/mysql -u root mysql"
  echo "    mysql> show tables"
  echo
  echo "Try 'mysqld --help' if you have problems with paths.  Using --log"
  echo "gives you a log in $ldata that may be helpful."
  echo
  echo "Please consult the MySQL manual section"
  echo "'Problems running mysql_install_db', and the manual section that"
  echo "describes problems on your OS.  Another information source are the"
  echo "MySQL email archives available at http://lists.mysql.com/."
  echo
  echo "Please check all of the above before mailing us!  And remember, if"
  echo "you do mail us, you MUST use the $scriptdir/mysqlbug script!"
  echo
  exit 1
fi
#在这里已经是安装完数据库了，这里只是将$fill_help_tables（帮助信息） 脚本刷新到数据库
s_echo "Filling help tables..."
if { echo "use mysql;"; cat $fill_help_tables; } | $mysqld_install_cmd_line > /dev/null
then
  s_echo "OK"
else
  echo
  echo "WARNING: HELP FILES ARE NOT COMPLETELY INSTALLED!"
  echo "The \"HELP\" command might not work properly."
fi

# Don't output verbose information if running inside bootstrap or using
# --srcdir for testing.  In such cases, there's no end user looking at
# the screen.
#如果是非--cross-bootstrap并且是非源码安装，则会提示修改root密码等方法
if test "$cross_bootstrap" -eq 0 && test -z "$srcdir"
then
  s_echo
  s_echo "To start mysqld at boot time you have to copy"
  s_echo "support-files/mysql.server to the right place for your system"

  echo
  echo "PLEASE REMEMBER TO SET A PASSWORD FOR THE MySQL root USER !"
  echo "To do so, start the server, then issue the following commands:"
  echo
  echo "$bindir/mysqladmin -u root password 'new-password'"
  echo "$bindir/mysqladmin -u root -h $hostname password 'new-password'"
  echo
  echo "Alternatively you can run:"
  echo "$bindir/mysql_secure_installation"
  echo
  echo "which will also give you the option of removing the test"
  echo "databases and anonymous user created by default.  This is"
  echo "strongly recommended for production servers."
  echo
  echo "See the manual for more instructions."
  #如果是非rpm包安装会提示启动数据库方法
  if test "$in_rpm" -eq 0
  then
    echo
    echo "You can start the MySQL daemon with:"
    echo "cd $basedir ; $bindir/mysqld_safe &"
    echo
    echo "You can test the MySQL daemon with mysql-test-run.pl"
    echo "cd $basedir/mysql-test ; perl mysql-test-run.pl"
  fi

  echo
  echo "Please report any problems with the $scriptdir/mysqlbug script!"
  echo
fi

exit