glob Function

public function glob(tame, wild)

NAME

glob(3f) - [fpm_strings:COMPARE] compare given string for match to
pattern which may contain wildcard characters
(LICENSE:PD)

SYNOPSIS

logical function glob(string, pattern )

 character(len=*),intent(in) :: string
 character(len=*),intent(in) :: pattern

DESCRIPTION

glob(3f) compares given STRING for match to PATTERN which may contain wildcard characters.

In this version to get a match the entire string must be described by PATTERN. Trailing whitespace is significant, so trim the input string to have trailing whitespace ignored.

OPTIONS

string   the input string to test to see if it contains the pattern.
pattern  the following simple globbing options are available

         o "?" matching any one character
         o "*" matching zero or more characters.
           Do NOT use adjacent asterisks.
         o Both strings may have trailing spaces which
           are ignored.
         o There is no escape character, so matching strings with
           literal question mark and asterisk is problematic.

EXAMPLES

Example program

program demo_glob
implicit none
! This main() routine passes a bunch of test strings
! into the above code.  In performance comparison mode,
! it does that over and over. Otherwise, it does it just
! once. Either way, it outputs a passed/failed result.
!
integer :: nReps
logical :: allpassed
integer :: i
 allpassed = .true.

 nReps = 10000
 ! Can choose as many repetitions as you're expecting
 ! in the real world.
 nReps = 1

 do i=1,nReps
  ! Cases with repeating character sequences.
  allpassed=allpassed .and. test("a*abab", "a*b", .true.)
  !!cycle
  allpassed=allpassed .and. test("ab", "*?", .true.)
  allpassed=allpassed .and. test("abc", "*?", .true.)
  allpassed=allpassed .and. test("abcccd", "*ccd", .true.)
  allpassed=allpassed .and. test("bLah", "bLaH", .false.)
  allpassed=allpassed .and. test("mississippi", "*sip*", .true.)
  allpassed=allpassed .and. &
   & test("xxxx*zzzzzzzzy*f", "xxx*zzy*f", .true.)
  allpassed=allpassed .and. &
   & test("xxxx*zzzzzzzzy*f", "xxxx*zzy*fffff", .false.)
  allpassed=allpassed .and. &
   & test("mississipissippi", "*issip*ss*", .true.)
  allpassed=allpassed .and. &
   & test("xxxxzzzzzzzzyf", "xxxx*zzy*fffff", .false.)
  allpassed=allpassed .and. &
   & test("xxxxzzzzzzzzyf", "xxxx*zzy*f", .true.)
  allpassed=allpassed .and. test("xyxyxyzyxyz", "xy*z*xyz", .true.)
  allpassed=allpassed .and. test("xyxyxyxyz", "xy*xyz", .true.)
  allpassed=allpassed .and. test("mississippi", "mi*sip*", .true.)
  allpassed=allpassed .and. test("ababac", "*abac*", .true.)
  allpassed=allpassed .and. test("aaazz", "a*zz*", .true.)
  allpassed=allpassed .and. test("a12b12", "*12*23", .false.)
  allpassed=allpassed .and. test("a12b12", "a12b", .false.)
  allpassed=allpassed .and. test("a12b12", "*12*12*", .true.)

  ! Additional cases where the '*' char appears in the tame string.
  allpassed=allpassed .and. test("*", "*", .true.)
  allpassed=allpassed .and. test("a*r", "a*", .true.)
  allpassed=allpassed .and. test("a*ar", "a*aar", .false.)

  ! More double wildcard scenarios.
  allpassed=allpassed .and. test("XYXYXYZYXYz", "XY*Z*XYz", .true.)
  allpassed=allpassed .and. test("missisSIPpi", "*SIP*", .true.)
  allpassed=allpassed .and. test("mississipPI", "*issip*PI", .true.)
  allpassed=allpassed .and. test("xyxyxyxyz", "xy*xyz", .true.)
  allpassed=allpassed .and. test("miSsissippi", "mi*sip*", .true.)
  allpassed=allpassed .and. test("miSsissippi", "mi*Sip*", .false.)
  allpassed=allpassed .and. test("abAbac", "*Abac*", .true.)
  allpassed=allpassed .and. test("aAazz", "a*zz*", .true.)
  allpassed=allpassed .and. test("A12b12", "*12*23", .false.)
  allpassed=allpassed .and. test("a12B12", "*12*12*", .true.)
  allpassed=allpassed .and. test("oWn", "*oWn*", .true.)

  ! Completely tame (no wildcards) cases.
  allpassed=allpassed .and. test("bLah", "bLah", .true.)

  ! Simple mixed wildcard tests suggested by IBMer Marlin Deckert.
  allpassed=allpassed .and. test("a", "*?", .true.)

  ! More mixed wildcard tests including coverage for false positives.
  allpassed=allpassed .and. test("a", "??", .false.)
  allpassed=allpassed .and. test("ab", "?*?", .true.)
  allpassed=allpassed .and. test("ab", "*?*?*", .true.)
  allpassed=allpassed .and. test("abc", "?**?*?", .true.)
  allpassed=allpassed .and. test("abc", "?**?*&?", .false.)
  allpassed=allpassed .and. test("abcd", "?b*??", .true.)
  allpassed=allpassed .and. test("abcd", "?a*??", .false.)
  allpassed=allpassed .and. test("abcd", "?**?c?", .true.)
  allpassed=allpassed .and. test("abcd", "?**?d?", .false.)
  allpassed=allpassed .and. test("abcde", "?*b*?*d*?", .true.)

  ! Single-character-match cases.
  allpassed=allpassed .and. test("bLah", "bL?h", .true.)
  allpassed=allpassed .and. test("bLaaa", "bLa?", .false.)
  allpassed=allpassed .and. test("bLah", "bLa?", .true.)
  allpassed=allpassed .and. test("bLaH", "?Lah", .false.)
  allpassed=allpassed .and. test("bLaH", "?LaH", .true.)

  ! Many-wildcard scenarios.
  allpassed=allpassed .and. test(&
  &"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa&
  &aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab",&
  &"a*a*a*a*a*a*aa*aaa*a*a*b",&
  &.true.)
  allpassed=allpassed .and. test(&
  &"abababababababababababababababababababaacacacacacacac&
  &adaeafagahaiajakalaaaaaaaaaaaaaaaaaffafagaagggagaaaaaaaab",&
  &"*a*b*ba*ca*a*aa*aaa*fa*ga*b*",&
  &.true.)
  allpassed=allpassed .and. test(&
  &"abababababababababababababababababababaacacacacacaca&
  &cadaeafagahaiajakalaaaaaaaaaaaaaaaaaffafagaagggagaaaaaaaab",&
  &"*a*b*ba*ca*a*x*aaa*fa*ga*b*",&
  &.false.)
  allpassed=allpassed .and. test(&
  &"abababababababababababababababababababaacacacacacacacad&
  &aeafagahaiajakalaaaaaaaaaaaaaaaaaffafagaagggagaaaaaaaab",&
  &"*a*b*ba*ca*aaaa*fa*ga*gggg*b*",&
  &.false.)
  allpassed=allpassed .and. test(&
  &"abababababababababababababababababababaacacacacacacacad&
  &aeafagahaiajakalaaaaaaaaaaaaaaaaaffafagaagggagaaaaaaaab",&
  &"*a*b*ba*ca*aaaa*fa*ga*ggg*b*",&
  &.true.)
  allpassed=allpassed .and. test("aaabbaabbaab", "*aabbaa*a*", .true.)
  allpassed=allpassed .and. &
  test("a*a*a*a*a*a*a*a*a*a*a*a*a*a*a*a*a*",&
  &"a*a*a*a*a*a*a*a*a*a*a*a*a*a*a*a*a*", .true.)
  allpassed=allpassed .and. test("aaaaaaaaaaaaaaaaa",&
  &"*a*a*a*a*a*a*a*a*a*a*a*a*a*a*a*a*a*", .true.)
  allpassed=allpassed .and. test("aaaaaaaaaaaaaaaa",&
  &"*a*a*a*a*a*a*a*a*a*a*a*a*a*a*a*a*a*", .false.)
  allpassed=allpassed .and. test(&
  &"abc*abcd*abcde*abcdef*abcdefg*abcdefgh*abcdefghi*abcdefghij&
  &*abcdefghijk*abcdefghijkl*abcdefghijklm*abcdefghijklmn",&
  & "abc*abc*abc*abc*abc*abc*abc*abc*abc*abc*abc*abc*abc*abc&
  &*abc*abc*abc*",&
  &.false.)
  allpassed=allpassed .and. test(&
  &"abc*abcd*abcde*abcdef*abcdefg*abcdefgh*abcdefghi*abcdefghij&
  &*abcdefghijk*abcdefghijkl*abcdefghijklm*abcdefghijklmn",&
  &"abc*abc*abc*abc*abc*abc*abc*abc*abc*abc*abc*abc*",&
  &.true.)
  allpassed=allpassed .and. test("abc*abcd*abcd*abc*abcd",&
  &"abc*abc*abc*abc*abc", .false.)
  allpassed=allpassed .and. test( "abc*abcd*abcd*abc*abcd*abcd&
  &*abc*abcd*abc*abc*abcd", &
  &"abc*abc*abc*abc*abc*abc*abc*abc*abc*abc*abcd",&
  &.true.)
  allpassed=allpassed .and. test("abc",&
  &"********a********b********c********", .true.)
  allpassed=allpassed .and.&
  &test("********a********b********c********", "abc", .false.)
  allpassed=allpassed .and. &
  &test("abc", "********a********b********b********", .false.)
  allpassed=allpassed .and. test("*abc*", "***a*b*c***", .true.)

  ! A case-insensitive algorithm test.
  ! allpassed=allpassed .and. test("mississippi", "*issip*PI", .true.)
 enddo

 if (allpassed)then
    write(*,'(a)')"Passed",nReps
 else
    write(*,'(a)')"Failed"
 endif
contains
! This is a test program for wildcard matching routines.
! It can be used either to test a single routine for correctness,
! or to compare the timings of two (or more) different wildcard
! matching routines.
!
function test(tame, wild, bExpectedResult) result(bpassed)
use fpm_strings, only : glob
   character(len=*) :: tame
   character(len=*) :: wild
   logical          :: bExpectedResult
   logical          :: bResult
   logical          :: bPassed
   bResult = .true.    ! We'll do "&=" cumulative checking.
   bPassed = .false.   ! Assume the worst.
   write(*,*)repeat('=',79)
   bResult = glob(tame, wild) ! Call a wildcard matching routine.

   ! To assist correctness checking, output the two strings in any
   ! failing scenarios.
   if (bExpectedResult .eqv. bResult) then
      bPassed = .true.
      if(nReps == 1) write(*,*)"Passed match on ",tame," vs. ", wild
   else
      if(nReps == 1) write(*,*)"Failed match on ",tame," vs. ", wild
   endif

end function test
end program demo_glob

Expected output

REFERENCE

The article “Matching Wildcards: An Empirical Way to Tame an Algorithm” in Dr Dobb’s Journal, By Kirk J. Krauss, October 07, 2014

Arguments

Type IntentOptional Attributes Name
character(len=*) :: tame

A string without wildcards to compare to the globbing expression

character(len=*) :: wild

A (potentially) corresponding string with wildcards

Return Value logical

result of test


Source Code

function glob(tame,wild)

! @(#)fpm_strings::glob(3f): function compares text strings, one of which can have wildcards ('*' or '?').

logical                    :: glob       !! result of test
character(len=*)           :: tame       !! A string without wildcards to compare to the globbing expression
character(len=*)           :: wild       !! A (potentially) corresponding string with wildcards
character(len=len(tame)+1) :: tametext
character(len=len(wild)+1) :: wildtext
character(len=1),parameter :: NULL=char(0)
integer                    :: wlen
integer                    :: ti, wi
integer                    :: i
character(len=:),allocatable :: tbookmark, wbookmark
! These two values are set when we observe a wildcard character. They
! represent the locations, in the two strings, from which we start once we've observed it.
   tametext=tame//NULL
   wildtext=wild//NULL
   tbookmark = NULL
   wbookmark = NULL
   wlen=len(wild)
   wi=1
   ti=1
   do                                            ! Walk the text strings one character at a time.
      if(wildtext(wi:wi) == '*')then             ! How do you match a unique text string?
         do i=wi,wlen                            ! Easy: unique up on it!
            if(wildtext(wi:wi)=='*')then
               wi=wi+1
            else
               exit
            endif
         enddo
         if(wildtext(wi:wi)==NULL) then        ! "x" matches "*"
            glob=.true.
            return
         endif
         if(wildtext(wi:wi) /= '?') then
            ! Fast-forward to next possible match.
            do while (tametext(ti:ti) /= wildtext(wi:wi))
               ti=ti+1
               if (tametext(ti:ti)==NULL)then
                  glob=.false.
                  return                         ! "x" doesn't match "*y*"
               endif
            enddo
         endif
         wbookmark = wildtext(wi:)
         tbookmark = tametext(ti:)
      elseif(tametext(ti:ti) /= wildtext(wi:wi) .and. wildtext(wi:wi) /= '?') then
         ! Got a non-match. If we've set our bookmarks, back up to one or both of them and retry.
         if(wbookmark/=NULL) then
            if(wildtext(wi:)/= wbookmark) then
               wildtext = wbookmark;
               wlen=len_trim(wbookmark)
               wi=1
               ! Don't go this far back again.
               if (tametext(ti:ti) /= wildtext(wi:wi)) then
                  tbookmark=tbookmark(2:)
                  tametext = tbookmark
                  ti=1
                  cycle                          ! "xy" matches "*y"
               else
                  wi=wi+1
               endif
            endif
            if (tametext(ti:ti)/=NULL) then
               ti=ti+1
               cycle                             ! "mississippi" matches "*sip*"
            endif
         endif
         glob=.false.
         return                                  ! "xy" doesn't match "x"
      endif
      ti=ti+1
      wi=wi+1
      if (tametext(ti:ti)==NULL) then          ! How do you match a tame text string?
         if(wildtext(wi:wi)/=NULL)then
            do while (wildtext(wi:wi) == '*')    ! The tame way: unique up on it!
               wi=wi+1                           ! "x" matches "x*"
               if(wildtext(wi:wi)==NULL)exit
            enddo
         endif
         if (wildtext(wi:wi)==NULL)then
            glob=.true.
            return                               ! "x" matches "x"
         endif
         glob=.false.
         return                                  ! "x" doesn't match "xy"
      endif
   enddo
end function glob