sublist

Prototype: sublist(list, head_or_tail, max_elements)

Return type: slist

Description: Returns list of up to max_elements of list, obtained from head or tail depending on head_or_tail.

This function can accept many types of data parameters.

Arguments:

list: string - CFEngine variable identifier or inline JSON - in the range: .*
head_or_tail: - Whether to return elements from the head or from the tail of the list - one of
- head
- tail
max_elements: int - Maximum number of elements to return - in the range: 0,99999999999

Example:

body common control
{
  bundlesequence => { "test" };
}

bundle agent test
{
  vars:
    "test"
      slist => {
        1, 2, 3, "one", "two", "three", "long string", "four", "fix", "six",
      };

    "test_head9999" slist => sublist("test", "head", 9999);
    "test_head1" slist => sublist("test", "head", 1);
    "test_head0" slist => sublist("test", "head", 0);
    "test_tail9999" slist => sublist("test", "tail", 9999);
    "test_tail10" slist => sublist("test", "tail", 10);
    "test_tail2" slist => sublist("test", "tail", 2);
    "test_tail1" slist => sublist("test", "tail", 1);
    "test_tail0" slist => sublist("test", "tail", 0);

  reports:
    "The test list is $(test)";
    "This line should not appear: $(test_head0)";
    "The head(1) of the test list is $(test_head1)";
    "The head(9999) of the test list is $(test_head9999)";
    "This line should not appear: $(test_tail0)";
    "The tail(1) of the test list is $(test_tail1)";
    "The tail(10) of the test list is $(test_tail10)";
    "The tail(2) of the test list is $(test_tail2)";
    "The tail(9999) of the test list is $(test_tail9999)";
}

R: The test list is 1
R: The test list is 2
R: The test list is 3
R: The test list is one
R: The test list is two
R: The test list is three
R: The test list is long string
R: The test list is four
R: The test list is fix
R: The test list is six
R: The head(1) of the test list is 1
R: The head(9999) of the test list is 1
R: The head(9999) of the test list is 2
R: The head(9999) of the test list is 3
R: The head(9999) of the test list is one
R: The head(9999) of the test list is two
R: The head(9999) of the test list is three
R: The head(9999) of the test list is long string
R: The head(9999) of the test list is four
R: The head(9999) of the test list is fix
R: The head(9999) of the test list is six
R: The tail(1) of the test list is six
R: The tail(10) of the test list is 1
R: The tail(10) of the test list is 2
R: The tail(10) of the test list is 3
R: The tail(10) of the test list is one
R: The tail(10) of the test list is two
R: The tail(10) of the test list is three
R: The tail(10) of the test list is long string
R: The tail(10) of the test list is four
R: The tail(10) of the test list is fix
R: The tail(10) of the test list is six
R: The tail(2) of the test list is fix
R: The tail(2) of the test list is six
R: The tail(9999) of the test list is 1
R: The tail(9999) of the test list is 2
R: The tail(9999) of the test list is 3
R: The tail(9999) of the test list is one
R: The tail(9999) of the test list is two
R: The tail(9999) of the test list is three
R: The tail(9999) of the test list is long string
R: The tail(9999) of the test list is four
R: The tail(9999) of the test list is fix
R: The tail(9999) of the test list is six

Output:

R: The test list is 1
R: The test list is 2
R: The test list is 3
R: The test list is one
R: The test list is two
R: The test list is three
R: The test list is long string
R: The test list is four
R: The test list is fix
R: The test list is six
R: The head(1) of the test list is 1
R: The head(9999) of the test list is 1
R: The head(9999) of the test list is 2
R: The head(9999) of the test list is 3
R: The head(9999) of the test list is one
R: The head(9999) of the test list is two
R: The head(9999) of the test list is three
R: The head(9999) of the test list is long string
R: The head(9999) of the test list is four
R: The head(9999) of the test list is fix
R: The head(9999) of the test list is six
R: The tail(1) of the test list is six
R: The tail(10) of the test list is 1
R: The tail(10) of the test list is 2
R: The tail(10) of the test list is 3
R: The tail(10) of the test list is one
R: The tail(10) of the test list is two
R: The tail(10) of the test list is three
R: The tail(10) of the test list is long string
R: The tail(10) of the test list is four
R: The tail(10) of the test list is fix
R: The tail(10) of the test list is six
R: The tail(2) of the test list is fix
R: The tail(2) of the test list is six
R: The tail(9999) of the test list is 1
R: The tail(9999) of the test list is 2
R: The tail(9999) of the test list is 3
R: The tail(9999) of the test list is one
R: The tail(9999) of the test list is two
R: The tail(9999) of the test list is three
R: The tail(9999) of the test list is long string
R: The tail(9999) of the test list is four
R: The tail(9999) of the test list is fix
R: The tail(9999) of the test list is six

History: The collecting function behavior was added in 3.9.

See also: nth(), filter(), about collecting functions, and data documentation.

sublist

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