Yes you can pass arguments in borne style shells like bash. For example:
Code:
#!/bin/bash
my_func () {
echo "my_func number of arguments: $#"
echo "my_func arg 1 is $1"
echo "my_func arg 2 is $2"
echo "my_func arg 3 is $3"
echo "my_func arg 4 is $4"
echo "my_func arg 5 is $5"
}
my_func hello there bob
The return value is a little different - it must be an integer between 0 and 255, and is assigned to $? when the function returns. For example:
Code:
#!/bin/bash
random_0_to_3 () {
return $(($RANDOM % 4))
}
for ((i=0; i<5; i++)); do
random_0_to_3
echo "return value was $?"
done
In general, the return value is only used to determine success or failure of the function, in the same way you'd use the value of $? after calling a regular shell command.
If you want your function to produce some output which can then be used, you can use stdout, and run the command with the $() syntax. For example:
Code:
#!/bin/bash
quantity_description () {
if [ $1 -ge 4 ]; then echo "a lot of beaks to feed"
elif [ $1 -eq 3 ]; then echo "quite a few beady eyes staring at me"
elif [ $1 -ge 2 ]; then echo "a pair of them"
elif [ $1 -eq 1 ]; then echo "just one, all on his lonesome"
elif [ $1 -eq 0 ]; then echo "none at all"
fi
}
for ((i=0; i<10; i++)); do
number=$((RANDOM % 6))
echo "I have $number penguins, which makes $(quantity_description $number)"
done
pass arguments and return values from a function in UNIX
