安装oracle时在用户下的.bash_profile文件里配置的变量谁能给我解释解释啥意思，越详细越好，跪求了

[ks520813]

trap " " 0 1 2 3 5 9 15
trap clear 0
export TMP=/tmp
export TMPDIR=$TMP
export ORACLE_BASE=/app/oracle
export ORACLE_HOME=$ORACLE_BASE/product/10.2.0/db_1
export ORACLE_SID=dmorcl
export ORACLE_TERM=xterm
export PATH=$ORACLE_HOME/bin:$PATH
#export LANG=en_US
export TNS_ADMIN=$ORACLE_HOME/network/admin
export NLS_LANG=AMERICAN_AMERICA.ZHS16GBK
export LANG=AMERICAN_AMERICA.ZHS16GBK
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:$ORACLE_HOME/lib32:/lib:/usr/lib:$ORACLE_HOME/ctx/lib:$ORACLE_HOME/rdbms/lib:/app/dm6/lib32:/app/dm6/lib:/lib:/usr/lib
export CLASSPATH=$ORACLE_HOME/jre:$ORACLE_HOME/jlib:$ORACLE_HOME/rdbms/jlib
export PATH=$PATH:$HOME/bin:$ORACLE_HOME/bin:$ORACLE_BASE:/usr/local/bin:/etc:/usr/sbin
export ODBCINI=/etc/odbc.ini
export ODBCSYSINI=/etc
#export ODBCINI=/app/dm51/configinfo/odbc.ini
umask 022
unset USERNAME

还有export ODBCINI=/etc/odbc.ini这个文件里写的是啥意思[localdp]
Description = MySQL
Driver = /app/dm51/lib32/libmyodbc3_r-3.51.25.so
Server = 192.168.1.26
Database = dp
Port = 3307
Socket =
Option = 7602432
Stmt =



[dm6dp]
Description = dumporacle
Driver = /app/dm6/lib32/libmyodbc3_r.so
Server = 192.168.1.26
Database = dp
Port = 3307
Socket = /tmp/mysql-dma.sock
Option = 7602432
Stmt =
CHARSET = gbk



[dp]
Description = dump oracle
Driver = /app/dm6/lib/libmyodbc3_r.so
Server = 192.168.1.26
Database = dp
Port = 3307
Socket =
Option = 7602432
Stmt =


[zkb]
Description = dump MYsql
Driver = /app/dm6/lib/libmyodbc3_r.so
Server = 192.168.1.26
Database = zkb
Port = 3307
Socket =
Option = 7602432
Stmt



[dpdma]
Description = dump oracle
Driver = /app/dm6/lib/libmyodbc3_r.so
Server = 192.168.1.26
Database = dp
Port = 3307
Socket = /tmp/mysql-dma.sock
Option = 7602433
Stmt =
CHARSET = gbk




[dpo]
Description = dump oracle
#Driver = /app/dm51/lib/libmyodbc3_r.so
Driver = /app/dm6/lib/libmyodbc3_r.so
Server = 192.168.1.10
Database = dp
Port = 3307
Socket =
Option = 7602432
Stmt

[dp30]
Description = DM51
Driver = /app/dm6/lib/libmyodbc3_r.so
Server = 192.168.1.30
Database = dp
Port = 3306
Socket =
Option = 7602432
Stmt =



[db2]
Driver = DB2
Description = db2 odbc