How can I check if PostgreSQL is installed or not via Linux script?

Question

I want to check in a script if PostgreSQL is installed or not on Linux and print the result. Any suggestions on how to do the check?

What do you mean by "PostgreSQL is installed"? Pgsql client? Client libraries? Pgsql server? — GreyCat, Apr 27 '11 at 20:05
See also these generic BASH commands: https://stackoverflow.com/a/677212/1736679 — Efren, Jun 05 '18 at 01:23

score 134 · Accepted Answer · edited May 23 '17 at 12:26

134

What about trying the which command?

If you were to run which psql and Postgres is not installed there appears to be no output. You just get the terminal prompt ready to accept another command:

> which psql
>

But if Postgres is installed you'll get a response with the path to the location of the Postgres install:

> which psql
/opt/boxen/homebrew/bin/psql

Looking at man which there also appears to be an option that could help you out:

-s      No output, just return 0 if any of the executables are found, or
        1 if none are found.

So it seems like as long as whatever scripting language you're using can can execute a terminal command you could send which -s psql and use the return value to determine if Postgres is installed. From there you can print that result however you like.

I do have postgres installed on my machine so I run the following

> which -s psql
> echo $?
0

which tells me that the command returned 0, indicating that the Postgres executable was found on my machine.

Here's the information about using echo $?

edited May 23 '17 at 12:26

Community

1
1

answered Apr 05 '13 at 00:29

campo

1,456
1
11
3

2

The only option `which` has for me is `-a` (print all matching pathnames of each argument), resulting in an illegal option if I use `-s`. – Dennis Sep 04 '14 at 16:09
Hey @Dennis I'm not sure what your motivations are, but I think in the spirit of my original response, you could probably do something using the -a flag. If there is no output then you can assume it is not installed, and if there is output you know that it is (and where) it's installed because you get the path back. Let me know if that's helpful or if you have any other thoughts. – campo Sep 08 '14 at 20:50
The problem with `which` is that it varies a lot over different operating systems. But you're right that the `-a` flag can be used, you can even use no flag at all: `if which foo >/dev/null; then echo exists; fi`. Another problem is that this will only search your PATH. – Dennis Sep 09 '14 at 08:56
2

`which psql` will not tell you if the Postgres **server** is installed. It's possible to install the client package (psql) without the server – Sep 23 '19 at 14:42

score 40 · Answer 2 · answered Sep 23 '19 at 14:38

40

We can simply write:

psql --version

output show like:

psql (PostgreSQL) 11.5 (Ubuntu 11.5-1.pgdg18.04+1)

answered Sep 23 '19 at 14:38

Chandan Sharma

2,321
22
22

Which will only tell you if `psql` is installed, not if the server is installed (and it reports the **psql** version, not the version of a potentially installed server) – Sep 23 '19 at 14:42

Draco Ater · Answer 3 · 2011-04-27T11:55:33.740

9

If it is debian based.

aptitude show postgresql | grep State

But I guess you can just try to launch it with some flag like --version, that simply prints some info and exits.

Updated using "service postgres status". Try:

service postgres status
if [ "$?" -gt "0" ]; then
  echo "Not installed".
else
  echo "Intalled"
fi

edited Apr 27 '11 at 11:55

answered Apr 27 '11 at 11:29

Draco Ater

20,820
8
62
86

It's noteworthy that this command would only work on the Debian based family of Linux distros. – nkr1pt Apr 27 '11 at 11:34
1

didnt worked ,no command found, i know command `service posrgres status`, but how to check result – Nirmal- thInk beYond Apr 27 '11 at 11:35
I don't have it installed, so it printed out "posrgres: unrecognized service" – Draco Ater Apr 27 '11 at 11:37
some systems don't have the `service` command. In Ubuntu or Debian, I'd check for `/etc/init.d/postgres status` or something like that. – Adriano Varoli Piazza Apr 27 '11 at 11:57
I should point out that if it says "posrgres: unrecognized service" [sic], you might still have "postgres" installed. Just sayin', in case somebody copies and pastes. – rossdavidh Feb 02 '13 at 16:44

score 6 · Answer 4 · answered Dec 27 '13 at 00:48

There is no single simple way to do it, because PostgreSQL might be installed and set up in many different ways:

Installed from source in a user home directory
Installed from source into /opt or /usr/local, manually started or started by an init script
Installed from distributor rpm / deb packages and started via init script
Installed from 3rd party rpm / deb packages and started via init script
Installed from packages but not set to start
Client installed, connecting to a server on a different computer
Installed and running but not on the default PATH or default port

You can't rely on psql being on the PATH. You can't rely on there being only one psql on the system (multiple versions might be installed in different ways). You can't do it based on port, as there's no guarantee it's on port 5432, or that there aren't multiple versions.

Prompt the user and ask them.

score 5 · Answer 5 · answered Sep 05 '16 at 16:08

5

If you are running Debian Linux (or derivative) and if you have a postive return with > which psql, then simply type psql -V (capital "V") and you will get a return like: psql (PostgreSQL) 9.4.8

answered Sep 05 '16 at 16:08

Roland Shield

69
1
5

I presume this only indicates that the psql client exists rather than the server as OP clarified in his comment. Also the psql client version may mismatch the server version. – Pocketsand Jul 04 '17 at 16:04

score 5 · Answer 6 · answered Apr 27 '11 at 13:31

5

There is no straightforward way to do this. All you can do is check with the package manager (rpm, dpkg) or probe some likely locations for the files you want. Or you could try to connect to a likely port (5432) and see if you get a PostgreSQL protocol response. But none of this is going to be very robust. You might want to review your requirements.

answered Apr 27 '11 at 13:31

Peter Eisentraut

35,221
12
85
90

2

Absolutely right. I have installed my PostgreSQL server from sources, under `teapot` user name and changed binary / service names to `TeaPotSQL`. No other users have permissions to read directory where it is installed. Default port is also changed. Go find it :-) – Apr 27 '11 at 13:35

score 4 · Answer 7 · edited Mar 12 '14 at 21:16

And if everything else fails from these great choice of answers, you can always use "find" like this. Or you may need to use sudo

If you are root, just type $$> find / -name 'postgres'

If you are a user, you will need sudo priv's to run it through all the directories

I run it this way, from the / base to find the whole path that the element is found in. This will return any files or directories with the "postgres" in it.

You could do the same thing looking for the pg_hba.conf or postgresql.conf files also.

score 3 · Answer 8 · answered Nov 07 '18 at 20:11

For many years I used the command:

ps aux | grep postgres

On one hand it is useful (for any process) and gives useful info (but from process POV). But on the other hand it is for checking if the server you know, you already installed is running.

At some point I found this tutorial, where the usage of the locate command is shown. It looks like this command is much more to the point for this case.

score 2 · Answer 9 · answered Mar 30 '18 at 07:19

2

aptitude show postgresql | grep Version worked for me

answered Mar 30 '18 at 07:19

user2584621

2,305
2
15
9

score 1 · Answer 10 · edited Dec 26 '13 at 07:20

1

Go to bin directory of postgres db such as /opt/postgresql/bin & run below command :

[...bin]# ./psql --version

psql (PostgreSQL) 9.0.4

Here you go . .

edited Dec 26 '13 at 07:20

Sujith PS

4,776
3
34
61

answered Jan 08 '13 at 04:43

Finn

912
1
16
53

We can simply write: `psql --version` output show like: ```psql (PostgreSQL) 11.5 (Ubuntu 11.5-1.pgdg18.04+1)``` – Chandan Sharma Sep 23 '19 at 14:36

score 0 · Answer 11 · edited Jan 11 '17 at 10:13

0

You may also check in /opt mount in following path /opt/PostgresPlus/9.5AS/bin/

edited Jan 11 '17 at 10:13

Tom

4,257
6
33
49

answered Jan 11 '17 at 09:17

vinoy vincent

1

score 0 · Answer 12 · answered Sep 29 '20 at 15:31

Well, all answersabove are good but not in all cases.

Basically check the folder /etc/postgresql/

in most cases there will be one subfolder eg. /etc/postgresql/11/ (or /etc/postgresql/12) which means that you have installed 11 (or 12) version, however in many cases you may have many of such subfolders, so having them all means that all those versions had been ever installed and could be in use ... so be aware of this important trace.

ps using Ubuntu 18.04

score 0 · Answer 13 · answered Apr 04 '23 at 20:03

0

Go window services ad search for PostGreSQL. here I found

answered Apr 04 '23 at 20:03

Zia Khan

188
2
9

Nikhil · Answer 14 · 2023-05-26T11:02:09.940

0

dpkg -l | grep postgres

RUN the above command and if you get the output as shown in the image then it does not exist on your system

Source:-Click here for more info

edited May 26 '23 at 11:02

answered May 26 '23 at 10:54

Nikhil

21
5

How can I check if PostgreSQL is installed or not via Linux script?

14 Answers14