Shell Variables

• $@ is a list of all the parameters passed in to a function
• $# is the number of parameters passed in to a function
• $? is the exit status of the last ran function

which cat
/bin/cat
echo $?
0 # This is good

which
echo $?
1 # This is bad (an error because no argument was provided)

+
zsh: command not found: +
echo $?
127 # This is bad too (127 means "command not found")

• $1, $2, ..., represent variables used inside of functions.

myecho() { echo $1 }
myecho "hey"
"hey"