[dzaima]

Of note of course is termux, which is a proper terminal, complete with a custom apt repo.

For cases where an adb shell is needed (modify external storage, slightly more permissions if not rooted) it's approximately possible to just copy necessary executables and .so files from termux to /data/local/tmp/ for adb (with some LD_LIBRARY_PATH & co setup), allowing running bash, htop, etc.

[matan-h]

I use this to copy programs from termux.

in termux (you need lld [pkg i lld]):

   mkdir /sdcard/.adb
   cp `which bash` /sdcard/.adb
   cp $(ldd `which bash`|cut -d ">" -f2) /sdcard/.adb

in adb shell:

   cd /data/local/tmp
   cp /sdcard/.adb/bash
   cp /sdcard/.adb/*.so
   LD_LIBRARY_PATH=.
   ./bash