The phrase "a command that" is correct and usable in written English.
It can be used when referring to a specific directive or instruction that is being given or discussed.
Example: "The software requires a command that initiates the backup process automatically."
Alternatives: "an instruction that" or "a directive that".
After the Japanese attack on Pearl Harbor (December 1941), Nimitz was elevated to commander in chief of the Pacific Fleet, a command that brought both land and sea forces under his authority.
This is a command that turns off the modem's speaker.
He called on Sunni Arabs to kill Shiites, a command that has been issued before.
Controllers sent a command that should have forced all four sensors to give a "dry" reading.
The batch file contains a command that reboots the local machine by calling c Windows32/System32/shutdown.
Stacked beneath, in far smaller type, was a command that began with a sexually explicit four-letter word and ended with the word "cake".
And he does, with an intelligence and a command that are very impressive, and that can also, like his subject's, be a little daunting.
It has emerged that staff at Pixar nearly deleted the animation for Toy Story 2 after someone mistakenly ran a command that removes everything on the file system.
West complains about massages and cars, culminating with a command that makes me smile every time I hear it: "Hurry up with my damn croissants!" The line, like his tweets, is something that only West could deliver with conviction.
In a separate episode in Oruzgan Province, two members of the United States Forces-Afghanistan, a command that includes many Special Operations forces, were killed on Thursday in what is also being investigated as a possible insider attack.
My household is staring down seven required-reading books, two reading journals and two hefty math assignments, plus the pointed suggestion (nearly a command) that each girl make a long list of the books she reads "for pleasure".
