preg_match and regex - allow or exclude characters

Question

I have problem with allowing specified characters in preg_match. I've tried making following pattern: /^[A-Za-z0-9 !@#$%&()-_\\[\\]:;\\"'|,.\\?\\/]/ Right now it allows everything, even * which is not there.

I know that there's this rule that before regex specified characters I have to put "\\" before character. Correct me if I'm wrong.

Can someone explain me how does this work?

I want to allow this chars: AZ az 0-9 !@#$%&()-_[]:;"'|,.?/ (and of course spaces)

And exclude this: ~`^*+={}<>\\

Answer 1

An unescaped hyphen needs to be at first or last position in a character class or it needs to be escaped. Otherwise it is considered a range. So use:

/^[A-Za-z0-9 !@#$%&()_\[\]:;\"'|,.\?\/-]/

In your regex /^[A-Za-z0-9 !@#$%&()-_\\[\\]:;\\"'|,.\\?\\/]/ where - is in the middle of and ) (ASCII: 41) and _ (ASCII: 95), hence matching all the characters in this range.

Also you need to use anchors to match entire input:

/^[A-Za-z0-9 !@#$%&()_\[\]:;\"'|,.\?\/-]+$/

Answer 2

This part )-_ in the character class is a range of characters.
From ) to _ .

You probably should escape the dash .. )\\-_ then its just a character.

  41    29  )       73  49  I      
  42    2A  *       74  4A  J      
  43    2B  +       75  4B  K      
  44    2C  ,       76  4C  L      
  45    2D  -       77  4D  M      
  46    2E  .       78  4E  N      
  47    2F  /       79  4F  O      
  48    30  0       80  50  P      
  49    31  1       81  51  Q      
  50    32  2       82  52  R      
  51    33  3       83  53  S      
  52    34  4       84  54  T      
  53    35  5       85  55  U      
  54    36  6       86  56  V      
  55    37  7       87  57  W      
  56    38  8       88  58  X      
  57    39  9       89  59  Y      
  58    3A  :       90  5A  Z      
  59    3B  ;       91  5B  [      
  60    3C  <       92  5C  \      
  61    3D  =       93  5D  ]      
  62    3E  >       94  5E  ^      
  63    3F  ?       95  5F  _