The command `ldd bin/${EPICS_HOST_ARCH}/xxx | grep vmc` is used to determine if the **xxx** binary executable file in the **bin/${EPICS_HOST_ARCH}** directory has a dynamic dependency on any shared libraries containing the string "vmc" in their names. Here's what the command does:
-`ldd` lists the dynamic dependencies of a binary executable file. It shows the shared libraries that the executable requires to run successfully.
-`bin/${EPICS_HOST_ARCH}/xxx` specifies the path to the **xxx** binary executable file.
-`| grep vmc`:
- the `|` symbol is a pipe operator that redirects the output of the `ldd` command to the next command in the pipeline.
-`grep vmc` is a command that searches for the string "vmc" in the output of the previous command (`ldd` in this case). It filters the output and displays only the lines that contain the string "vmc".
