**More list commands - lsearch, lsort, lrange**
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Lists can be searched with the `lsearch` command, sorted with the `lsort` command, and a range of list entries can be extracted with the `lrange` command.
`lsearch ?options? list pattern`: Searches `list` for an entry that matches `pattern`, and returns the index for the first match, or a -1 if there is no match. By default, `lsearch` uses "glob" patterns for matching. See the section on [Tcl Tutorial Lesson 16a%|%Simple pattern matching - "globbing"%|%]
`lsort ?options? list`: Sorts `list` and returns a new list in the sorted order. By default, it sorts the list into alphabetic order. Note that this command returns the sorted list as a result, instead of sorting the list in place. If you have a list in a variable, the way to sort it is like so: `set lst [[lsort $lst]]`
`lrange list first last`: Returns a list composed of the `first` through `last` entries in the list. If `first` is less than or equal to 0, it is treated as the first list element. If `last` is `end` or a value greater than the number of elements in the list, it is treated as the end. If `first` is greater than `last` then an empty list is returned.
While the options are not discussed here, they make these commands very powerful.
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***Example***
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set list [list {Washington 1789} {Adams 1797} {Jefferson 1801} \
{Madison 1809} {Monroe 1817} {Adams 1825} ]
set x [lsearch $list Washington*]
set y [lsearch $list Madison*]
incr x
incr y -1 ;# Set range to be not-inclusive
set subsetlist [lrange $list $x $y]
puts "These presidents served between Washington and Madison"
foreach item $subsetlist {
puts "Starting in [lindex $item 1]: President [lindex $item 0]"
}
set x [lsearch $list Madison*]
set srtlist [lsort $list]
set y [lsearch $srtlist Madison*]
puts "\n$x Presidents came before Madison chronologically"
puts "$y Presidents came before Madison alphabetically"
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<<discussion>> Resulting output
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These presidents served between Washington and Madison
Starting in 1797: President Adams
Starting in 1801: President Jefferson
3 Presidents came before Madison chronologically
3 Presidents came before Madison alphabetically
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<<enddiscussion>>
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