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Full Discussion: IF statement with square brackets
Top Forums Shell Programming and Scripting IF statement with square brackets Post 302983624 by Don Cragun on Friday 14th of October 2016 03:21:22 AM
Old 10-14-2016
The real question is not what the region is when the code works or fails, but to what do the expansions of the three shell variables: com_dir, dup_file_name_chk, and save_dir expand when the code works and to what do they expand when it fails. One might guess that it is failing when one of those variables contain one or more whitespace characters. One might also guess that the following would also work:
Code:
if [ -f "$com_dir/$dup_file_name_chk" ] || 
[ -f "$save_dir/$dup_file_name_chk" ]
then
.
.
.
fi

You haven't told us what shell you're using, but if [[ expression ]] is working and you're running on AIX, I'll assume you are using ksh or bash. The command:
Code:
[ -f $com_dir/$dup_file_name_chk ]

is a shell built-in utility that performs the same parameter expansion and field splitting that happens whenever the shell evaluates a command line. Without the double quotes surrounding the parameter expansions, if there are whitespace characters in the expansions of those variables, field splitting will cause one or both of those tests to fail. It will also fail if $dup_file_name_chk expands to an empty string. but in that case the double bracket test would also fail.

The command:
Code:
[[ -f $com_dir/$dup_file_name_chk ]]

is part of the syntax of the shell; not a utility. Parameter expansion still occurs in this case, but field splitting does not occur.
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LEARN ABOUT HPUX

xpolygonregion

XPolygonRegion()														  XPolygonRegion()

Name
  XPolygonRegion - generate a region from points in a polygon.

Synopsis
  Region XPolygonRegion(points, n, fill_rule)
	XPoint points[];
	int n;
	int fill_rule;

Arguments
  points    Specifies a pointer to an array of points.

  n	    Specifies the number of points in the polygon.

  fill_rule Specifies  whether	areas overlapping an odd number of times should be part of the region (WindingRule) or not part of the region
	    (EvenOddRule).  See Volume One, Chapter 5, The Graphics Context, for a description of the fill rule.

Returns
  The created region.

Description
  XPolygonRegion() creates a region defined by connecting the specified points, and returns a pointer to be used to refer to the region.

  Regions are located relative to a point (the region origin) which is common to all regions.  In XPolygonRegion(), the coordinates specified
  in points are relative to the region origin.	By specifying all points relative to the drawable in which they will be used, the region ori-
  gin can be coincident with the drawable origin.  It is up to the application whether to interpret the location of the region relative to  a
  drawable or not.

  If  the  region  is to be used as a clip_mask by calling XSetRegion(), the upper-left corner of the region relative to the drawable used in
  the graphics request will be at (xoffset + clip_x_origin, yoffset + clip_y_origin), where xoffset and yoffset are the offset of the  region
  (if  any)  and  clip_x_origin  and clip_y_origin are elements of the GC used in the graphics request.  The fill_rule can be either of these
  values:

  EvenOddRule	 Areas overlapping an odd number of times are not part of the region.

  WindingRule	 Overlapping areas are always filled.

  For more information on structures, see Volume One, Chapter 6, Drawing Graphics and Text.

Structures
  Region is a pointer to an opaque structure type.

See Also
  XClipBox(), XCreateRegion(),	XDestroyRegion(),  XEmptyRegion(),  XEqualRegion(),  XIntersectRegion(),  XOffsetRegion(),  XPointInRegion(),
  XRectInRegion(), XSetRegion(), XShrinkRegion(), XSubtractRegion(), XUnionRectWithRegion(), XUnionRegion(), XXorRegion().

Xlib - Regions															  XPolygonRegion()
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