STScI Logo

imnode xray.ximages



imnode -- edit the pixfile directory info of one or more IRAF images


imnode images node


Imnode edits one or more IRAF image files to change the i_pixfile specification of the pixel file. The pixel file pathname is stored in the IRAF parameter "i_pixfile" and describes where the pixel file (containing the actual data) is stored. This pixfile parameter usually has a node name in it, so that images can be accessed from remote machines using IRAF networking calls. These IRAF networking calls prompt for a password before accessing remote images, in order to protect against unauthorized access over the network.

For example, if an image has a pixfile value such as


then accessing the image from cfa242 does not require networking, but accessing the image from any other machine does require networking and the user will be prompted for his password. This is unnecessary in cases where the directory (e.g. /pool30) is actually mounted on the remote machine, since ordinary I/O access would be sufficient. Pool directories, for example, are commonly mounted everywhere on a LAN.

For such cases, imnode can be used to "de-node" the pathname, so that node information is removed in the pixel path name. To do this, specify a null string "" or "0!" for the node parameter. In both cases, the actual node is changed to "0!". IRAF recognizes this special node as signifying that no networking I/O is performed (and therefore no password is required).

One can, however, specify any node name (with a trailing "!") or any directory name (with a trailing "/"). For example, if one normally runs IRAF on cfa242, but is running on cfa241 temporarily, the node of an image can be changed to cfa241 so that networking be turned off while accessing that image from cfa241. If one has moved the .pix files from one directory to another, the task can be used to change the i_pixfile pathname to find the data in the new directory.


images = "" prompt = list of images to de-node

A list of image files (.imh) to be edited. Templates can be used to specify one or more images (e.g., "f*.imh").

node = "0!" prompt = new node or directory name

The new pixfile dir name. This can be a new node name (ending with "!") or a new pathname (ending with "/"). If the null string is input, the node "0!" is used, which means that no IRAF networking will be performed.

(display = 2) [int]

The display level. A value of 0 indicates no display, 1 lists the image names as they are processed, >=2 lists the image names as well as the pixfile parameter value before and after editing.


1. De-node a list of images beginning with the letter f.

	ni> imnode f*.imh display=2 node=""

foo.imh:  cfa242!/pool30/eric/foo.pix -> 0!/pool30/eric/foo.pix
foo1.imh:  cfa242!/pool30/eric/foo1.pix -> 0!/pool30/eric/foo1.pix
foo2.imh:  cfa242!/pool30/eric/foo2.pix -> 0!/pool30/eric/foo2.pix
foo3.imh:  cfa242!/pool30/eric/foo3.pix -> 0!/pool30/eric/foo3.pix

2. Change the pixfile directory of images beginning with f.

	ni> imnode f*.imh display=2 node="/u7/eric/test/"

foo.imh:  cfa242!/pool30/eric/foo.pix -> /u7/eric/test/foo.pix
foo1.imh:  cfa242!/pool30/eric/foo1.pix -> /u7/eric/test/foo1.pix
foo2.imh:  cfa242!/pool30/eric/foo2.pix -> /u7/eric/test/foo2.pix
foo3.imh:  cfa242!/pool30/eric/foo3.pix -> /u7/eric/test/foo3.pix


The task is fast, since it only edits one parameter in each image.



Source Code · Search Form · STSDAS