I am trying to understand how Bash executes commands. When I run cal, I see this:
December 2021
Su Mo Tu We Th Fr Sa
1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31
However, when I run CAL, I see this:
December 2021
Mo 6 13 20 27
Tu 7 14 21 28
We 1 8 15 22 29
Th 2 9 16 23 30
Fr 3 10 17 24 31
Sa 4 11 18 25
Su 5 12 19 26
As the results are slightly different, I assumed that two separate programs were running. When I run which cal, I see /usr/bin/cal. When I run which CAL, I see /usr/bin/CAL. However, when I run ls -l /usr/bin I do not see an entry for CAL listed.
What is CAL? Is it a program? Is it an alias to another program? Where is it defined?
Thank you.
