1 files changed, 80 insertions, 0 deletions
diff --git a/sys/qpoe/qpread.x b/sys/qpoe/qpread.x
new file mode 100644
index 00000000..c25fe506
--- /dev/null
+++ b/sys/qpoe/qpread.x
@@ -0,0 +1,80 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include <syserr.h>
+include "qpoe.h"
+
+# QP_READ -- Read a range of elements from a parameter.  Works for any
+# parameter, including scalar parameters and both static and variable
+# length array valued parameters.  Automatic datatype conversion is
+# performed for the primitive types.
+
+int procedure qp_read (qp, param, buf, maxelem, first, datatype)
+
+pointer qp			#I QPOE descriptor
+char	param[ARB]		#I parameter name
+char	buf[ARB]		#O user data buffer to receive data
+int	maxelem			#I max number of data elements to read
+int	first			#I first data element to read
+char	datatype[ARB]		#I datatype to be returned
+
+pointer	sp, fm, sym, tbuf, isym, osym
+int	fd, sz_itype, sz_otype, nelem, itype, otype
+
+pointer	qp_gpsym()
+int	fm_getfd(), qp_sizeof(), read(), qp_dtype()
+errchk	qp_bind, qp_gpsym, fm_getfd, seek, read, syserrs
+
+begin
+	if (QP_ACTIVE(qp) == NO)
+	    call qp_bind (qp)
+
+	fm = QP_FM(qp)
+	otype = qp_dtype (qp, datatype, osym)
+
+	# Lookup the symbol in the symbol table.
+	sym = qp_gpsym (qp, param)
+	if (sym == NULL)
+	    call syserrs (SYS_QPUKNPAR, param)
+	else {
+	    itype = S_DTYPE(sym)
+	    isym  = sym
+	}
+
+	# Determine the number of inbounds elements.
+	nelem = max(0, min(maxelem, S_NELEM(sym) - first + 1))
+	if (first <= 0)
+	    call syserrs (SYS_QPINDXOOR, param)
+
+	# Verify that any type conversion is legal.
+	if (otype != itype)
+	    if (min(otype,itype) < TY_CHAR || max(otype,itype) > TY_DOUBLE)
+		call syserrs (SYS_QPBADCONV, param)
+
+	# Open the lfile and read the data segment.
+	fd = fm_getfd (fm, S_LFILE(sym), READ_ONLY, 0)
+
+	if (nelem > 0) {
+	    sz_itype = qp_sizeof (qp, itype, isym, IMMEDIATE)
+	    sz_otype = qp_sizeof (qp, otype, osym, INSTANCEOF)
+
+	    # Read and output the data.
+	    call seek (fd, S_OFFSET(sym) + (first - 1) * sz_itype)
+	    if (sz_itype <= sz_otype) {
+		# Read the data directly into the user's buffer.
+		nelem = read (fd, buf, nelem * sz_itype) / sz_itype
+		if (nelem > 0 && otype != itype)
+		    call acht (buf, buf, nelem, itype, otype)
+	    } else {
+		# Read the data into a temporary buffer.
+		call smark (sp)
+		call salloc (tbuf, nelem * sz_itype, TY_CHAR)
+		nelem = read (fd, Memc[tbuf], nelem * sz_itype) / sz_itype
+		if (nelem > 0)
+		    call acht (Memc[tbuf], buf, nelem, itype, otype)
+		call sfree (sp)
+	    }
+	}
+
+	call fm_retfd (fm, S_LFILE(sym))
+	return (nelem)
+end