1 files changed, 62 insertions, 0 deletions
diff --git a/pkg/tbtables/fitsio/ftgext.f b/pkg/tbtables/fitsio/ftgext.f
new file mode 100644
index 00000000..66094d2f
--- /dev/null
+++ b/pkg/tbtables/fitsio/ftgext.f
@@ -0,0 +1,62 @@
+C----------------------------------------------------------------------
+        subroutine ftgext(iunit,extno,xtend,status)
+
+C       'Get Extension'
+C       move i/o pointer to another extension (or the primary HDU) and
+C       initialize all the common block parameters which describe the
+C       extension
+
+C       iunit   i  fortran unit number
+C       extno   i  number of the extension to point to.
+C       xtend   i  type of extension:   0 = the primary HDU
+C                                       1 = an ASCII table
+C                                       2 = a binary table
+C       status  i  output error status
+C
+C       written by Wm Pence, HEASARC/GSFC, June, 1991
+
+        integer iunit,extno,xtend,status
+
+C       COMMON BLOCK DEFINITIONS:--------------------------------------------
+        integer nb,ne
+        parameter (nb = 20)
+        parameter (ne = 200)
+        integer bufnum,chdu,hdutyp,maxhdu,hdstrt,hdend,nxthdr,dtstrt
+        integer nxtfld
+        logical wrmode
+        common/ft0001/bufnum(199),chdu(nb),hdutyp(nb),maxhdu(nb),
+     &  wrmode(nb),hdstrt(nb,ne),hdend(nb),nxthdr(nb),dtstrt(nb),nxtfld
+C       END OF COMMON BLOCK DEFINITIONS-----------------------------------
+
+        integer ibuff,xchdu,xhdend,xmaxhd
+
+        if (status .gt. 0)return
+
+        ibuff=bufnum(iunit)
+
+C       move to the beginning of the desired extension
+        call ftmbyt(iunit,hdstrt(ibuff,extno),.false.,status)
+        if (status .le. 0)then
+
+C               temporarily save parameters
+                xchdu=chdu(ibuff)
+                xmaxhd=maxhdu(ibuff)
+                xhdend=hdend(ibuff)
+
+C               initialize various parameters about the CHDU
+                chdu(ibuff)=extno
+                maxhdu(ibuff)=max(extno,maxhdu(ibuff))
+C               the location of the END record is currently unknown, so 
+C               temporarily just set it to a very large number
+                hdend(ibuff)=2000000000
+
+C               determine the structure of the CHDU
+                call ftrhdu(iunit,xtend,status)
+                if (status .gt. 0)then
+C                       couldn't read the extension so restore previous state
+                        chdu(ibuff)= xchdu
+                        maxhdu(ibuff)=xmaxhd
+                        hdend(ibuff)= xhdend
+                end if
+        end if
+        end