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Name

lsearch - See if a list contains a particular element

Synopsis

lsearch ?options? list pattern

Description

This command searches the elements of list to see if one of them matches pattern. If so, the command returns the index of the first matching element (unless the options -all or -inline are specified.) If not, the command returns -1. The option arguments indicates how the elements of the list are to be matched against pattern and it must have one of the following values:

-all
Changes the result to be the list of all matching indices (or all matching values if -inline is specified as well.)
-ascii
The list elements are to be examined as Unicode strings (the name is for backward-compatability reasons.) This option is only meaningful when used with -exact or -sorted.
-decreasing
The list elements are sorted in decreasing order. This option is only meaningful when used with -sorted.
-dictionary
The list elements are to be compared using dictionary-style comparisons (see lsort for a fuller description). This option is only meaningful when used with -exact or -sorted, and it is only distinguishable from the -ascii option when the -sorted option is given, because values are only dictionary-equal when exactly equal.
-exact
The list element must contain exactly the same string as pattern.
-glob
Pattern is a glob-style pattern which is matched against each list element using the same rules as the string match command.
-increasing
The list elements are sorted in increasing order. This option is only meaningful when used with -sorted.
-inline
The matching value is returned instead of its index (or an empty string if no value matches.) If -all is also specified, then the result of the command is the list of all values that matched.
-integer
The list elements are to be compared as integers. This option is only meaningful when used with -exact or -sorted.
-not
This negates the sense of the match, returning the index of the first non-matching value in the list.
-real
The list elements are to be compared as floating-point values. This option is only meaningful when used with -exact or -sorted.
-regexp
Pattern is treated as a regular expression and matched against each list element using the rules described in the re_syntax reference page.
-sorted
The list elements are in sorted order. If this option is specified, lsearch will use a more efficient searching algorithm to search list. If no other options are specified, list is assumed to be sorted in increasing order, and to contain ASCII strings. This option is mutually exclusive with -glob and -regexp, and is treated exactly like -exact when either -all, or -not is specified.
-start index
The list is searched starting at position index. If index has the value end, it refers to the last element in the list, and end-integer refers to the last element in the list minus the specified integer offset.

If option is omitted then it defaults to -glob. If more than one of -exact, -glob, -regexp, and -sorted is specified, whichever option is specified last takes precedence. If more than one of -ascii, -dictionary, -integer and -real is specified, the option specified last takes precedence. If more than one of -increasing and -decreasing is specified, the option specified last takes precedence.

Examples


lsearch {a b c d e} c => 2
lsearch -all {a b c a b c} c => 2 5
lsearch -inline {a20 b35 c47} b* => b35
lsearch -inline -not {a20 b35 c47} b* => a20
lsearch -all -inline -not {a20 b35 c47} b* => a20 c47
lsearch -all -not {a20 b35 c47} b* => 0 2
lsearch -start 3 {a b c a b c} c => 5

See Also

foreach(n) , list(n) , lappend(n) , lindex(n) , linsert(n) , llength(n) , lset(n) , lsort(n) , lrange(n) , lreplace(n)

Keywords

list, match, pattern, regular expression, search, string

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