amatch Interface

amatch(3f) - [M_MATCH] look for pattern matching regular expression; returns its location
(LICENSE:PD)

loc = amatch(line, from, pat, tagbeg, tagend)

 character(len=*),intent(in) :: line
 integer,intent(in)          :: from
 character                   :: pat(MAXPAT)
 integer                     :: tagbeg(MAXTAGS), tagend(MAXTAGS)
 integer                     :: loc

AMATCH scans LINE starting at location FROM, looking
for a pattern which matches the regular expression coded
in PAT. If the pattern is found, its starting location
in LINE is returned. If the pattern is not found, AMATCH
returns 0.

The regular expression in PAT must have been previously
encoded by GETPAT(3f) or MAKPAT(3f). (For a complete description
of regular expressions, see the manpage for M_match.)

AMATCH(3f) is a special-purpose version of MATCH(3f), which should
be used in most cases.

LINE           input line to scan
FROM           beginning location to start scan from
PAT            coded regular expression encoded by GETPAT(3f) or MAKPAT(3f)
TAGBEG,TAGEND  element "i + 1" returns start or end, respectively, of "i"th tagged subpattern

LOC   returns location match was found or zero (0) if no match remains

 program demo_amatch
 use :: M_match, only : getpat, amatch
 use :: M_match, only : MAXPAT, MAXARG, MAXLINE, MAXTAGS, YES, ERR
 implicit none
 ! find _ find patterns in text
 integer                      :: pat(MAXPAT)
 character(len=MAXARG-1)      :: argument
 integer                      :: stat
 integer                      :: ios
 integer                      :: len_arg
 integer                      :: loc
 integer                      :: ii
 character(len=MAXLINE-2)     :: line
 integer                      :: tagbeg(MAXTAGS),tagend(MAXTAGS)
 call get_command_argument(1, argument,status=stat,length=len_arg)
 if(stat.ne.0.or.argument.eq.'')then
    write(*,*)"usage: find pattern."
 elseif(getpat(argument(:len_arg), pat) .eq. ERR) then
    write(*,*)"illegal pattern."
 else
    INFINITE: do
       read(*,'(a)',iostat=ios)line
       tagbeg=-9999;tagend=-9999
       if(ios.ne.0)exit
       loc = amatch(trim(line), 1, pat, tagbeg, tagend) ! returns location/0
       if(loc.gt.0)then ! matched; if no match, loc is returned as 0
          write(*,'(*(a))')trim(line)
          ! (element "i + 1" returns start or end, respectively, of "i"th tagged subpattern)
          write(*,'(*(i0,1x,i0,1x,i0,/))')(ii,tagbeg(ii),tagend(ii),ii=1,size(tagbeg))
       endif
    enddo INFINITE
 endif
 end program demo_amatch

match, getpat, makpat

None

John S. Urban

"Software Tools" by Kernighan and Plauger , 1976

Public Domain