NAME
lsort - Sort the elements of a list
SYNOPSIS
lsort ?options? list
DESCRIPTION
-ascii
-dictionary
-integer
-real
-command command
-increasing
-decreasing
-index index
KEYWORDS

NAME

lsort - Sort the elements of a list

SYNOPSIS

lsort ?options? list

DESCRIPTION

This command sorts the elements of list, returning a new list in sorted order. The implementation of the lsort command uses the merge-sort algorithm which is a stable sort that has O(n log n) performance characteristics.

By default ASCII sorting is used with the result returned in increasing order. However, any of the following options may be specified before list to control the sorting process (unique abbreviations are accepted):

-ascii
Use string comparison with ASCII collation order. This is the default.

-dictionary
Use dictionary-style comparison. This is the same as -ascii except (a) case is ignored except as a tie-breaker and (b) if two strings contain embedded numbers, the numbers compare as integers, not characters. For example, in -dictionary mode, bigBoy sorts between bigbang and bigboy, and x10y sorts between x9y and x11y.

-integer
Convert list elements to integers and use integer comparison.

-real
Convert list elements to floating-point values and use floating comparison.

-command command
Use command as a comparison command. To compare two elements, evaluate a Tcl script consisting of command with the two elements appended as additional arguments. The script should return an integer less than, equal to, or greater than zero if the first element is to be considered less than, equal to, or greater than the second, respectively.

-increasing
Sort the list in increasing order (``smallest'' items first). This is the default.

-decreasing
Sort the list in decreasing order (``largest'' items first).

-index index
If this option is specified, each of the elements of list must itself be a proper Tcl sublist. Instead of sorting based on whole sublists, lsort will extract the index'th element from each sublist and sort based on the given element. The keyword end is allowed for the index to sort on the last sublist element. For example,
lsort -integer -index 1 {{First 24} {Second 18} {Third 30}}
returns {Second 18} {First 24} {Third 30}. This option is much more efficient than using -command to achieve the same effect.

KEYWORDS

element, list, order, sort
Copyright © 1993 The Regents of the University of California.
Copyright © 1994-1996 Sun Microsystems, Inc.
Copyright © 1999 Scriptics Corporation
Copyright © 1995-1997 Roger E. Critchlow Jr.