Very simple named arguments for bash functions

bash_function_named_args.bash

# Do not use in public facing servers as I am sure it can do bad things by malicious individuals
# Initialize variables and functions
  unset -f boo
  unset -f echoerror
  unset    other
  echoerr() { printf "%s\n" "$*" >&2; }

# Example bash function to show the use of:
#   required args                     "rqrd_arg"
#   named args                        "namd_arg"
#   named args with defaults          "namd_dflt"
#   pass by reference return variable "rvar"
# Only uses STDOUT if no return variable provided
  function boo() {
    echoerr ARGS:$@      ;# Illustration purpose only REMOVETHISLINE
    local rqrd_arg=$1; shift; [[ -z $rqrd_arg ]] && echoerr "ERROR: Missing required arg rqrd_arg" && return 1
    local namd_dflt=dflt ;# Define default argument
    unset rvar           ;# Prepare return value if provide
    local $*             ;# Evaluates named args. Ex: namd_dflt=4
    [[ -z $rvar ]] && echo "rqrd_arg:namd_dflt:namd_arg = $rqrd_arg:$namd_dflt:$namd_arg" || eval $rvar="'rqrd_arg:namd_dflt:namd_arg = $rqrd_arg:$namd_dflt:$namd_arg'"
  }

# Test the function boo
  export other
  boo 1 namd_arg=2           namd_dflt=4; echo errorcode=$? other=$other
  boo 1 namd_arg=2 invld_arg namd_dflt=4; echo errorcode=$? other=$other
  boo 1 namd_arg=2 invld_arg            ; echo errorcode=$? other=$other
  boo                                   ; echo errorcode=$? other=$other
  boo 1 rvar=other                      ; echo errorcode=$? other=$other



# Other useful examples

# Can override the env variables by passing them in as named args: Xproj2generic <file> PROJ=trunk
function Xgenric2proj() {
  # Help msg
  if [[ $# -lt 1 ]] || [[ $1 == help ]]; then
    echo "  ${FUNCNAME[0]} requires filename. Ex:Xproj2generic ~/.vim/session/prj_testbench.sxn.vim" >&2
    return 1
  fi
  file=$1; shift
  local $*; # Evaluate/create named args Ex: this=that 
  sed -i.bak "s/\$PROJ/$PROJ/g" $file
  sed -i.bak "s/\$USER/$USER/g" $file
  sed -i.bak "s/\$WORKSPACE/$WORKSPACE/g" $file
}

# Can override the env variables by passing them in as named args: Xproj2generic <file> PROJ=trunk
function Xproj2generic() {
  if [[ $# -lt 1 ]] || [[ $1 == help ]]; then
    echo "  ${FUNCNAME[0]} requires filename. Ex:Xgeneric2proj ~/.vim/session/prj_testbench.sxn.vim WORKSPACE=clean" >&2
    return 1
  fi
  file=$1; shift
  local $*; # Evaluate/create named args Ex: this=that 
  sed -i.bak "s/$PROJ/\$PROJ/g" $file
  sed -i.bak "s/$USER/\$USER/g" $file
  sed -i.bak "s/$WORKSPACE/\$WORKSPACE/g" $file
}