# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.

include	"qpoe.h"

# QP_ASTR -- Set the value of a string parameter, creating the parameter if
# it does not already exist.  This works for the common case of string
# parameters allocated a fixed amount of space at create time (any type of
# string parameter can be written into if it already exists).  Additional
# control over the parameter attributes is possible if the parameter is
# explicitly created with qp_addf before being written into.

procedure qp_astr (qp, param, value, comment)

pointer	qp			#I QPOE descriptor
char	param[ARB]		#I parameter name
char	value[ARB]		#I parameter value
char	comment[ARB]		#I comment field, if creating parameter

int	nchars
int	qp_accessf(), strlen()
errchk	qp_accessf, qp_addf

begin
	# By default we allocate a somewhat bigger storage area than needed
	# to store the string, to permit updates of a similar length.	If
	# more control over the maximum string length is needed, QP_ADDF
	# should be called explicitly.

	if (qp_accessf (qp, param) == NO) {
	    nchars = (strlen(value) + INC_STRLEN-1) / INC_STRLEN * INC_STRLEN
	    call qp_addf (qp, param, "c", nchars, comment, 0)
	}

	call qp_pstr (qp, param, value)
end