To check the running LineageOS version from Termux, you can use standard Android shell commands. Here are the most reliable methods:

1. Check Build Prop

Run this command in Termux to extract the LineageOS version from the system properties:

getprop ro.lineage.version

or

getprop ro.modversion

This will return the LineageOS version (e.g., 18.1, 20, etc.).

2. Check Android Version (Fallback)

If the above doesn't work, you can check the Android version, which often matches the LineageOS base:

getprop ro.build.version.release

This will show the Android version (e.g., 11, 12, 13), which corresponds to LineageOS 18.1, 19, 20, etc.

3. Check Full Build Info

For more details, use:

getprop ro.build.display.id

This will show something like lineage_<device>-userdebug 11 RQ3A.211001.001 eng.<builder>.20230101.000000 dev-keys, where 11 is the Android version.

4. Check LineageOS Updater (if available)

If your device has the LineageOS Updater app, you can also check its logs or run:

su -c "pm list packages | grep updater"

Then inspect the updater app's version or logs for the OS version.

Note:

• You may need root access (su) for some commands.
• If you don’t have getprop, ensure Termux has access to Android’s shell environment.