谁能解释一下：
~$echo $PGDATA /Library/Postgresql/9.2/data ~$cd /Library/Postgresql/9.2/ /Library/Postgresql/9.2$sudo su postgres bash-3.2$echo $PGDATA <blank line> bash-3.2$pg_ctl start pg_ctl: no database directory specified and environment variable PGDATA unset Try "pg_ctl --help" for more information. bash-3.2$export PGDATA="/Library/Postgresql/9.2/data" bash-3.2$pg_ctl start server starting bash-3.2$
以下是我的〜/ .bashrc文件：
export PGDATA="/Library/Postgresql/9.2/data"
我不是在拼错PGDATA中的路径：
~$echo $PGDATA
/Library/Postgresql/9.2/data
export PGDATA="/Library/Postgresql/9.2/data"
解决方法
sudo can’t be assumed to keep the environment variables of its caller.
See its manpage for the details with your specific OS.
据我所知,环境变量附加到shell,据我所知,我在同一个shell中.
这对我有用：
~$cd /Library/Postgresql/9.2/ /Library/Postgresql/9.2$sudo -E su postgres
…
-E The -E (preserve environment) option will override the
env_reset option in sudoers(5)). It is only available when
either the matching command has the SETENV tag or the
setenv option is set in sudoers(5).
我只了解以下内容：
The -E (preserve environment) option
下一条评论：
When I su to postgres I do su – postgres. Notice the hyphen.
这是我的手册中关于连字符的说法：
-l Simulate a full login. The environment is discarded except for
HOME,SHELL,PATH,TERM,and USER. HOME and SHELL are modified
as above. USER is set to the target login. PATH is set to
``/bin:/usr/bin''. TERM is imported from your current environ-
ment. The invoked shell is the target login's,and su will
change directory to the target login's home directory.
- (no letter) The same as -l.
我没有看到它将如何保留PGDATA环境变量,这就是我尝试连字符时发生的事情：
/Library/Postgresql/9.2$sudo su - postgres Password: 7studs-computer:~ postgres$ls bin pgAdmin3.app data pg_env.sh doc scripts include share installer stackbuilder.app lib uninstall-postgresql.app 7studs-computer:~ postgres$pg_ctl start -bash: pg_ctl: command not found 7studs-computer:~ postgres$ls bin pgAdmin3.app data pg_env.sh doc scripts include share installer stackbuilder.app lib uninstall-postgresql.app 7studs-computer:~ postgres$cd bin 7studs-computer:bin postgres$ls clusterdb pg_config pgbench createdb pg_controldata pltcl_delmod createlang pg_ctl pltcl_listmod createuser pg_dump pltcl_loadmod dropdb pg_dumpall postgres droplang pg_receivexlog postmaster dropuser pg_resetxlog psql ecpg pg_restore reindexdb initdb pg_standby vacuumdb oid2name pg_test_fsync vacuumlo pg_archivecleanup pg_test_timing pg_basebackup pg_upgrade 7studs-computer:bin postgres$./pg_ctl start pg_ctl: no database directory specified and environment variable PGDATA unset Try "pg_ctl --help" for more information. 7studs-computer:bin postgres$
因此连字符对我不起作用(OSX 10.6.8).
