How to Create a New User on Ubuntu Server?

1. Restricting User 'malawi' from Installing System-wide Programs and Verifying Permissions

   chmod o-rx /home/jhuang
   ls -ld /home/jhuang
   cd /home/jhuang
   groups malawi
   sudo deluser malawi sudo
   jhuang@hamm:~$ groups malawi
   #malawi : malawi
   jhuang@hamm:~$ groups jhuang
   #jhuang : jhuang adm cdrom sudo dip plugdev lpadmin sambashare docker

2. Ensuring Full Permissions for User 'malawi' in Their Home Directory

   #chmod -R u=rwx,go= /home/malawi
   ls -ld /home/malawi
   #drwxr-xr-x
   sudo chown malawi:malawi /home/malawi
   #sudo chmod 700 /home/malawi
   #sudo chmod -R 700 /home/malawi
   sudo chmod 755 /home/malawi
   sudo chmod -R 755 /home/malawi
   ls -ld /home/malawi

3. Protecting Other Users' Directories from Access by 'malawi'

   sudo chmod o-rx /home/jhuang
   sudo chmod o-rx /mnt/h1/jhuang
   #for dir in /home/*; do
   #  if [ -d "$dir" ]; then
   #    sudo chmod o-rx "$dir"
   #  fi
   #done
   ls -ld /home/jhuang

4. Changing User Passwords

   sudo passwd malawi
   passwd

5. Changing User Passwords

   if (!requireNamespace("BiocManager", quietly = TRUE))
       install.packages("BiocManager")
   BiocManager::install("SeuratObject")
   install.packages("Seurat")

6.

    #(NOT GOOD) from 775 to o-rx 
    #sudo chmod o-rx /mnt/h1/jhuang
    #sudo chmod -R o-rx /mnt/h1/jhuang
    #sudo chmod o-rx /home/jhuang
    #sudo chmod -R o-rx /home/jhuang
    #from 775 to 750
    sudo chmod 750 /mnt/h1/jhuang
    sudo chmod -R 750 /mnt/h1/jhuang
    sudo chmod 750 /home/jhuang
    sudo chmod -R 750 /home/jhuang
    #END

1. install r and r-seurat with miniconda3

   mkdir -p ~/miniconda3
   wget https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh -O ~/miniconda3/miniconda.sh
   bash ~/miniconda3/miniconda.sh -b -u -p ~/miniconda3
   rm -rf ~/miniconda3/miniconda.sh
   ~/miniconda3/bin/conda init bash
   conda create -n r -c bioconda r r-seurat
   conda activate r
   #> .libPaths()
   #[1] "/home/malawi/miniconda3/envs/r/lib/R/library"
   if (!requireNamespace("remotes", quietly = TRUE))
     install.packages("remotes")
   remotes::install_github("satijalab/seurat-data")
   conda deactivate
   conda activate r
   R
   library(Seurat)
   library(SeuratData)
   library(ggplot2)
   library(patchwork)
   library(dplyr)