10-22-2008
Using unset to delete array elements
Hi,
I am writing a BASH script. My questions regard deleting elements of arrays.
I have an array:
michael-browns-powerbook-g4-15:~ msb65$ test_array=(1 2 3 4)
michael-browns-powerbook-g4-15:~ msb65$ echo ${test_array[@]}
1 2 3 4
To delete the second element of test_array I type:
michael-browns-powerbook-g4-15:~ msb65$ unset test_array[1]
michael-browns-powerbook-g4-15:~ msb65$ echo ${test_array[@]}
1 3 4
I would like to again delete the second element (which is now 3). So I repeat the previous two lines of code:
michael-browns-powerbook-g4-15:~ msb65$ unset test_array[1]
michael-browns-powerbook-g4-15:~ msb65$ echo ${test_array[@]}
1 3 4
- Why is it that the second element was not deleted? Am I not deleting array elements properly?
Thanks.
Mike
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LEARN ABOUT REDHAT
lreplace
lreplace(n) Tcl Built-In Commands lreplace(n)
__________________________________________________________________________________________________________________________________________________
NAME
lreplace - Replace elements in a list with new elements
SYNOPSIS
lreplace list first last ?element element ...?
_________________________________________________________________
DESCRIPTION
lreplace returns a new list formed by replacing one or more elements of list with the element arguments. first and last specify the first
and last index of the range of elements to replace. 0 refers to the first element of the list, and end (or any abbreviation of it) may be
used to refer to the last element of the list. If list is empty, then first and last are ignored.
If first is less than zero, it is considered to refer to the first element of the list. For non-empty lists, the element indicated by
first must exist.
If last is less than zero but greater than first, then any specified elements will be prepended to the list. If last is less than first
then no elements are deleted; the new elements are simply inserted before first.
The element arguments specify zero or more new arguments to be added to the list in place of those that were deleted. Each element argu-
ment will become a separate element of the list. If no element arguments are specified, then the elements between first and last are sim-
ply deleted. If list is empty, any element arguments are added to the end of the list.
SEE ALSO
lappend(n), lindex(n), linsert(n), list(n), llength(n), lrange(n), lsearch(n), lsort(n)
KEYWORDS
element, list, replace
Tcl 7.4 lreplace(n)