postgresql Postgres 看不到我的 PGDATA 环境变量
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Postgres cannot see my PGDATA environment variable
提问by 7stud
Can anyone explain this:
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$
The following is in my ~/.bashrc file:
以下是我的 ~/.bashrc 文件：
export PGDATA="/Library/PostgreSQL/9.2/data"
I'm not mis-spelling the path in PGDATA:
我没有拼错 PGDATA 中的路径：
~$ echo $PGDATA
/Library/PostgreSQL/9.2/data
export PGDATA="/Library/PostgreSQL/9.2/data"
采纳答案by 7stud
sudo can't be assumed to keep the environment variables of its caller. See its manpage for the details with your specific OS.
不能假定 sudo 保留其调用者的环境变量。有关您的特定操作系统的详细信息，请参阅其联机帮助页。
As far as I know, environment variables are attached to a shell, and as far as I can tell I'm in the same shell.
据我所知，环境变量附加到一个 shell，据我所知，我在同一个 shell 中。
This works for me:
这对我有用：
~$ 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).
I only understand the following:
我只明白以下几点：
The -E (preserve environment) option
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When I su to postgres I do su - postgres. Notice the hyphen.
当我 su 到 postgres 我做 su - postgres。注意连字符。
Here is what my man pages say about the hyphen:
这是我的手册页关于连字符的说明：
-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.
I don't see how that will preserve the PGDATA environment variable, and this is what happened when I tried the hyphen:
我看不出这将如何保留 PGDATA 环境变量，这就是我尝试使用连字符时发生的情况：
/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$
So the hyphen doesn't work for me (OSX 10.6.8).
所以连字符对我不起作用（OSX 10.6.8）。
