[SOLVED] Function for use as conditional

Faki · 04-13-2023, 12:31 PM

I want to write a bash function that tests whether a number or array values fall within the 8-bit possible values.

I want to use it as a conditional about whether all array elements are valid. The difficulty is setting up the exit status correctly when at least one value is outside range.

Code:

octxt ()
 {
  typeset -n _octary="$1"

  local xst
  for i in "${_octary[@]}"; do
    if (( i < 0 || i > 255 )); then
      xst=1  # Fail Value outside 8-Bit extent
    else
      xst=0  # Success Value within 8-Bit extent
    fi
  done

  return $xst

 }

metaed · 04-13-2023, 02:14 PM

Something like this?

Code:

octxt ()
 {
  typeset -n _octary="$1"

  local xst
  xst=0
  for i in "${_octary[@]}"; do
    if (( i < 0 || i > 255 )); then
      xst=1  # Fail Value outside 8-Bit extent
    fi
  done

  return $xst

 }

MadeInGermany · 04-15-2023, 08:50 AM

Return as soon as possible

Code:

octxt (){
  local -n _octary="$1"
  local i
  for i in "${_octary[@]}"; do
    (( i >= 0 && i <= 255 )) || return  # Fail Value outside 8-Bit extent
  done
}

Knowing that the last exit status is returned.

pan64 · 04-15-2023, 09:14 AM

yes, return as soon as possible, when you know it is not valid.
But unfortunately:

Code:

a="adfgarfg"
(( a >= 0 )) && echo ok
(( a <= 255 )) && echo ok

It won't work for non-numerical inputs and also may produce strange results (for example if a="12w")
bash is not really good at it.