Get Group Names on Linux/Unix

Linux¶

Get information of the staff group.
```
 $ getent group staff
 staff:x:20:
```
Get group ID of the staff group.
```
 $ getent group staff | cut -d: -f3
 20
```

Mac¶

Get information of the staff group.
```
 $ dscl . -read /Groups/staff 
```

Get group ID of the staff group.

 $ dscl . -read /Groups/staff | awk '($1 == "PrimaryGroupID:") { print $2 }'
 20

As a matter of fact, dscl in Mac is the equivalence of getent in Linux. Both of them can be used to query user information as well.

Querying user information using getent.
```
 getent passwd <uid>
```
Querying user information using dscl.
```
 dscl . -search /Users UniqueID <uid>
```

In both cases, you then need to parse the output to get the username. The output of getent is standard /etc/passwd format, something like this:

zamboni:x:1005:1005:Diego Zamboni,,,:/home/zamboni:/bin/bash

This is very easy to parse (using awk, for example) and gives you the full record at once. dscl only provides the field you searched for, something like this:

zamboni              UniqueID = (
    501
)

So if you want to get the full record, you would need to get the username and then query for it, like this:

dscl . -read /Users/zamboni

The output is harder to parse, in “keyword: value” form, but with many multiline values. You can also use the -plist option to get it in Apple’s plist format, which could be easier to parse.

Cross-platform Ways¶

You can also get group information using the grp module in Python.

import grp
print(grp.getgrnam("staff").gr_gid)