Suppose I have two lists:
lista="a b c d"
listb="e f"
I would like to write a function that returns the number of items on a given list:
>>foo $lista
4
>>foo $listb
2
I've tried using ${#<varname>[@]} syntax, also ${#!<varname>[@]}, unsuccessfully.
Thanks
You can use wc -w for this:
$ lista="a b c d"
$ wc -w <<< "$lista"
4
$ listb="e f"
$ wc -w <<< "$listb"
2
From man wc:
-w, --words
print the word counts
To make it function, use:
list_length () {
echo $(wc -w <<< "$@")
}
And then you can call it like:
list_length "a b c"
Put them into BASH array and look at array length.
a=($lista)
echo ${#a[@]}
4
a=($listb)
echo ${#a[@]}
2
If you indeed want to write a function, you can take advantage of normal parameter parsing and the fact that $# contains the number of parameters passed:
foo() { echo $#; }
