4 Environment Variables

catremote takes some input from Unix shell environment variables and these variables can be used to control its behaviour. Some of the variables are optional, but others are mandatory and must be set before catremote is invoked. The variables used are listed in Table 1 and described briefly below.

CATREM_URLREADER

catremote uses a separate program to submit the URL constituting a query to the server and return the table of results. The options available are described in Section 9.

CATREM_CONFIG

specifies the configuration file to be used. It should be set to either the URL (for a remote file) or the local file name, including a directory specification (for a local file). Configuration files are described in SSN/75[3]. The default configuration file used by CURSA is at URL:

http://dev.starlink.ac.uk/\~pwd/catremote/cursa.cfg

CATREM_MAXOBJ

is the maximum number of objects which the returned table is allowed to contain.

CATREM_ECHOURL

Controls whether the URL representing the query submitted to the remote server is also displayed to the user. The default is ‘no’; to see the URL set CATREM_ECHOURL to ‘yes’. Seeing the URL is potentially useful when debugging configuration files and servers but is not usually required for normal operation.

These environment variables are set up automatically when CURSA is started. However, if catremote is being used outside CURSA they need to be set up manually. Figure 1 shows an example script for this purpose. On Starlink systems it is available as file: