regmatch Function

public function regmatch(match, string, matches)

NAME

regmatch(3f) - [M_regex] return selected substring defined by the
               MATCHES(2,:) array

SYNOPSIS

function regmatch(match,string,matches)

character(len=matches(2,match)-matches(1,match)+1) :: regmatch
integer, intent(in)                                :: match, matches(2,*)
character(len=*), intent(in)                       :: string

DESCRIPTION

A convenience function to return a specific substring from the input
STRING, defined by the MATCHES() array.

OPTIONS

match      the count into the start and end matrix matches(:,MATCH)
string     the string to find the substrings in
matches    the start and end matrix generated from calling REGEXEC(3f).

RETURNS

regmatch   the selected substring extracted from STRING.

EXAMPLE

Sample program:

program demo_regmatch
! read regular expression from command line and look for it in lines read from stdin.
use M_regex, only: regex_type, regcomp, regexec, regmatch, regfree
implicit none
integer                      :: command_argument_length
character(len=:),allocatable :: command_argument
character(len=1024)          :: input_line
type(regex_type)             :: regex
logical                      :: match
integer,parameter            :: max_subexpressions=10
integer                      :: matches(2,max_subexpressions)
integer                      :: ios
   !find length of command argument
   call get_command_argument(number=1,length=command_argument_length)
   ! allocate a string long enough to hold the argument
   allocate(character(len=command_argument_length) :: command_argument)
   ! get the command argument
   call get_command_argument(1, command_argument)

   ! compile up regular expression
   call regcomp(regex,command_argument,'x')

   ! read lines and look for match to expression
   INFINITE: do
      read(*,'(a)',iostat=ios)input_line
      if(ios.ne.0)exit INFINITE
      ! look for a match in (remaining) string
      match=regexec(regex,input_line,matches)
      ! if no match found go for next line
      if(.not.match)cycle INFINITE
      ! show line with match
      write(*,'(a)') trim(input_line)
   enddo INFINITE

   ! free memory used for compiled regular expression
   call regfree(regex)

end program demo_regmatch

Arguments

Type IntentOptional Attributes Name
integer, intent(in) :: match
character(len=*), intent(in) :: string

character(len=matches(2,match)-matches(1,match)+1) :: regmatch ! intel internal compiler error version 19
integer, intent(in) :: matches(2,*)

Return Value character(len=:), allocatable


Source Code

function regmatch(match,string,matches)

! ident_3="@(#) M_exec regmatch(3f) return selected substrings defined by the regexec(3f) procedure"

integer, intent(in)                                :: match, matches(2,*)
character(len=*), intent(in)                       :: string
!!character(len=matches(2,match)-matches(1,match)+1) :: regmatch  ! intel internal compiler error version 19
character(len=:),allocatable :: regmatch

   regmatch = string(matches(1,match):matches(2,match))

end function regmatch