ex
Computer program
>
&tbnh=174&tbnw=289&usg=AI4_-kTIOLDMVpllQn3C4Xy7h3uegVbixA&vet=1&docid=IHXMefw0qM259M&itg=1&sa=X&ved=2ahUKEwjErdOu8N6FAxWicPEDHdxmBNEQ9QF6BAgAEAQ)
&tbnh=116&tbnw=116&usg=AI4_-kQWBL4yY-n6cHoQe-ayXnYVrHaT_w&vet=1&docid=0nHfNZctjbMW2M&sa=X&ved=2ahUKEwjErdOu8N6FAxWicPEDHdxmBNEQ9QF6BAgAEAY)
&tbnh=52&tbnw=148&usg=AI4_-kSXMQEo1wgRwQ5krEmoXCtcRnZ9Fw&vet=1&docid=bV94dqnyLXOQqM&sa=X&ved=2ahUKEwjErdOu8N6FAxWicPEDHdxmBNEQ9QF6BAgAEAg)
&tbnh=58&tbnw=150&usg=AI4_-kQPKF4gHL_wmwQKtwDCzCBemnZ8ZQ&vet=1&docid=bV94dqnyLXOQqM&sa=X&ved=2ahUKEwjErdOu8N6FAxWicPEDHdxmBNEQ9QF6BAgAEAo)
ex, short for EXtended, is a line editor for Unix systems originally written by Bill Joy in 1976, beginning with an earlier program written by Charles Haley. Multiple implementations of the program exist; they are standardized by POSIX. Wikipedia