The optional truth-valued expression immediately following the command is a command postconditional that controls whether or not GT.M executes the command.

expr contains a list of object file names, with or without wildcards, which ZRUPDATE publishes new versions to subscribers.

To remove routines, delete the object files and publish the names of the deleted object files. Removal requires file names to be explicitly specified, because patterns with wildcards cannot match deleted files.

ZRUPDATE rejects file-name arguments that are symbolic links or start with a percent-sign (%)

ZRUPDATE recognizes question-mark (?) as a single character wild-card

If the path to a file is non-existent, the request is ignored except in the case where one desires a currently shared object file (one that was accessed before it was deleted) to no longer be shared.

To effect auto-relink, GT.M creates small temporary files in the directory referred to by $gtm_linktmpdir (defaulting to $gtm_tmp, which in turn defaults to /tmp, if unspecified). The names of these files are of the form gtm-relinkctl<md5sum> where <md5sum> is a hash of the realpath() to an auto-relink directory. The group and permissions match those for the directory as described in the section Shared Resources Authorization Permissions in Appendix E (GT.M Security Philosophy) of the UNIX Administration and Operations Guide. FIS recommends that all processes that share a directory whose contents are subject to ZRUPDATE use the same value for $gtm_linktmpdir so that all processes see update notifications - with different values of $gtm_linktmpdir, a ZRUPDATE by a process with one value of $gtm_linktmpdir would not be observed by a process with a different value of that environment variable.

ZRUPDATE always updates the existing shared memory relinkctl information for a file with an existing entry.