ipcs provides information on the ipc facilities for which the calling process has read access.
In some implementations of ipcs the -a option will print all information available. In other implementations the -a option will print all resource types. Therefore, applications shall not use the -a option.
Some implements of ipcs implement more output formats than are specified here. These options are not consistent between differing implementations of ipcs. Therefore, only the -t -c and -p option flags may be used. At least one of the -t -c and -p options shall be specified.