name=isaacgd
useradd -m -s $(which bash) -d /users/$name $name
passwd $name
getent passwd $name

value=`cat config.txt`
value=$(<config.txt)

# Fork a pipe
echo "Hello world." | tee >(sed 's/^/1: /')  >(sed 's/^/2: /') >/dev/null

# Fork a pipe bis: more sophisticated
echo "Hello world." | tee >(md5sum | tee out1 | sed 's/^/md5 : /') >(sha1sum | tee out2 | sed 's/^/sha1: /') > out3

# For a pipe posix compliant
(
# 6
(
# 5
(
# 4
echo "Hello World" | tee /dev/fd/{4,5} > /dev/null
) 4>&1 | ( sed 's/^/one: /' > /dev/fd/6 )
) 5>&1 | ( sed 's/^/two: /' > /dev/fd/6 )
) 6>&1

shopt -s lastpipe; set +m
# permit last pipe command to execute in current shell; disable Monitor mode (i.e. job control)
{ echo -e "begin\ngrepme\nend" | tee /dev/fd/3 | sed -n '/grepme/p' | readarray -t a_filter; } 3>&1; echo "${a_filter[*]}"



# :from: https://catonmat.net/bash-redirections-cheat-sheet
cmd > file
# Redirect the standard output (stdout) ofcmdto a file.
cmd 1> file
# Same ascmd > file. 1 is the default file descriptor (fd) for stdout.
cmd 2> file
# Redirect the standard error (stderr) ofcmdto a file. 2 is the default fd for stderr.
cmd >> file
# Append stdout ofcmdto a file.
cmd 2>> file
# Append stderr ofcmdto a file.
cmd &> file
# Redirect stdout and stderr ofcmdto a file.
cmd > file 2>&1
# Another way to redirect both stdout and stderr ofascmd 2>&1 > file. Redirection order matters! cmdto a file. This is notthe same
cmd > /dev/null
# Discard stdout ofcmd.
cmd 2> /dev/null
# Discard stderr ofcmd.
cmd &> /dev/null
# Discard stdout and stderr ofcmd.
cmd < file
# Redirect the contents of the file to the standard input (stdin) ofcmd.


# Redirect a bunch of lines to the stdin. If'EOL'is quoted, text is treated literally. This is called a here-document.
cmd << EOL
line
line
EOL


# Redirect a bunch of lines to the stdin and strip the leading tabs.
cmd <<- EOL
<tab>foo
<tab><tab>bar
EOL

exec &> >(tee -a log.out)
# Redirect stdout and stderr to file
exec &> /dev/tty
# Reset stdout and stderr 

cmd <<< "string"
# Redirect a single line of text to the stdin ofcmd. This is called a here-string.
exec 2> file
# Redirect stderr of all commands to a file forever.
exec 3< file
# Open a file for reading using a custom file descriptor.
exec 3> file
# Open a file for writing using a custom file descriptor.
exec 3<> file
# Open a file for reading and writing using a custom file descriptor.
exec 3>&-
# Close a file descriptor.
exec 4>&3
# Make file descriptor 4 to be a copy of file descriptor 3. (Copy fd 3 to 4 .)
exec 4>&3-
# Copy file descriptor 3 to 4 and close file descriptor 3.
echo "foo" >&3
# Write to a custom file descriptor.
cat <&3
# Read from a custom file descriptor.
(cmd1; cmd2) > file
# Redirect stdout from multiple commands to a file (using a sub-shell).
{ cmd1; cmd2; } > file
# Redirect stdout from multiple commands to a file (faster; not using a sub-shell).
exec 3<> /dev/tcp/host/port
# Open a TCP connection tohost:port. (This is a bash feature, not Linux feature).
exec 3<> /dev/udp/host/port
# Open a UDP connection tohost:port. (This is a bash feature, not Linux feature).
cmd <(cmd1)
# Redirect stdout ofUseful whencmddoesn’t read from stdin directly.cmd1to an anonymous fifo, then pass the fifo tocmdas an argument.
cmd < <(cmd1)
# Redirect stdout ofBest example:diff <(find /path1 | sort) <(find /path2 | sort)cmd1to an anonymous fifo, then redirect the fifo to stdin of. cmd.
cmd <(cmd1) <(cmd2)
# Redirect stdout ofarguments tocmd. cmd1andcmd2to two anonymous fifos, then pass both fifos as
cmd1 >(cmd2)
# Runpipe as an argument tocmd2with its stdin connected to an anonymous fifo, and pass the filename of thecmd1.
cmd1 > >(cmd2)
# Runto this anonymous pipe.cmd2with its stdin connected to an anonymous fifo, then redirect stdout ofcmd
cmd1 | cmd2
# Redirect stdout ofsame ascmd2 < <(cmd1)cmd1to stdin of, same ascmd2> >(cmd2) cmd1. Pro-tip: This is the same as, same as< <(cmd1) cmd2cmd1 > >(cmd2). ,
cmd1 |& cmd2
#  Redirect stdout and stderr ofcmd1 2>&1 | cmd2for older bashes.cmd1 to stdin of cmd2 (bash 4.0+ only). Use
cmd | tee file
# Redirect stdout ofcmdto a file and print it to screen.
exec {filew}> file
# Open a file for writing using a named file descriptor called{filew}(bash 4.1+).
cmd 3>&1 1>&2 2>&3
# Swap stdout and stderr ofcmd.
cmd > >(cmd1) 2> >(cmd2)
# Send stdout ofcmdtocmd1and stderr ofcmdtocmd2.
cmd1 | cmd2 | cmd3 | cmd; echo ${PIPESTATUS[@]}
# Find out the exit codes of all piped commands.


# 

bash --init-file my-init-script

eval "$(declare -F | sed -e 's/-f /-fx /')"

# shellcheck disable=SC2155  # Declare and assign separately to avoid masking return values -> Prevent declare -a

# shellcheck disable=SC2092  # Remove backticks

# $@ is all command line parameters passed to the script.

# -o is for short options like -v

# -l is for long options with double dash like --version
options=$(getopt \
  -l "all,help,rosetta,site,vim,html,wiki" \
  -o "ahrsvxw" -- "$@")


# set --:

# If no arguments follow this option, then the positional parameters are unset. Otherwise, the positional parameters

# are set to the arguments, even if some of them begin with a ‘-’.
eval set -- "$options"
echo -n "Args: "
while true; do
  case "$1" in
    -a|--all)
      echo -n "All, "
      ((ball=1))
      ;;
    -h|--help)
      usage
      ;;
    -r|--rosetta)
      echo -n "Rosetta, "
      ((brosetta=1))
      ;;
    -s|--site)
      echo -n "Site, "
      ((bsite=1))
      ;;
    -v|--vim)
      echo -n "Vim, "
      ((bvim=1))
      ;;
    -w|--wiki)
      echo -n "Wiki, "
      ((bwiki=1))
      ;;
    -x|--html)
      echo -n "Html, "
      ((bhtml=1))
      ;;
    --)
      shift
      break
      ;;
  esac
  shift
done
echo