Provided by: tcl8.6-doc_8.6.14+dfsg-1build1_all bug

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 or (if options -all or -inline are
       specified) the empty string.  The option arguments indicates how the elements of the  list
       are to be matched against pattern and must have one of the values below:

   MATCHING STYLE OPTIONS
       If  all  matching style options are omitted, the default matching style is -glob.  If more
       than one matching style is specified, the last matching style given takes precedence.

       -exact Pattern is a literal string that is compared for exact equality against  each  list
              element.

       -glob  Pattern  is  a  glob-style pattern which is matched against each list element using
              the same rules as the string match command.

       -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 are specified.

   GENERAL MODIFIER OPTIONS
       These options may be given with all matching styles.

       -all   Changes  the  result to be the list of all matching indices (or all matching values
              if -inline is specified as well.) If indices are returned, the indices will  be  in
              numeric order. If values are returned, the order of the values will be the order of
              those values within the input list.

       -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.

       -not   This negates the sense of the match, returning the index of the first  non-matching
              value in the list.

       -start index
              The  list  is searched starting at position index.  The interpretation of the index
              value is the same  as  for  the  command  string  index,  supporting  simple  index
              arithmetic and indices relative to the end of the list.

   CONTENTS DESCRIPTION OPTIONS
       These  options  describe  how to interpret the items in the list being searched.  They are
       only meaningful when used with the -exact and  -sorted  options.   If  more  than  one  is
       specified, the last one takes precedence.  The default is -ascii.

       -ascii The  list elements are to be examined as Unicode strings (the name is for backward-
              compatibility reasons.)

       -dictionary
              The list elements are to be compared using dictionary-style comparisons (see  lsort
              for  a  fuller description). Note that this only makes a meaningful difference from
              the -ascii option when the  -sorted  option  is  given,  because  values  are  only
              dictionary-equal when exactly equal.

       -integer
              The list elements are to be compared as integers.

       -nocase
              Causes  comparisons  to  be handled in a case-insensitive manner.  Has no effect if
              combined with the -dictionary, -integer, or -real options.

       -real  The list elements are to be compared as floating-point values.

   SORTED LIST OPTIONS
       These options (only meaningful with the -sorted option) specify how the  list  is  sorted.
       If  more  than  one  is  given,  the  last  one  takes  precedence.  The default option is
       -increasing.

       -decreasing
              The list elements are sorted in decreasing order.  This option is  only  meaningful
              when used with -sorted.

       -increasing
              The  list  elements are sorted in increasing order.  This option is only meaningful
              when used with -sorted.

       -bisect
              Inexact search when the list elements are in sorted order. For an  increasing  list │
              the  last index where the element is less than or equal to the pattern is returned. │
              For a decreasing list the last index where the element is greater than or equal  to │
              the  pattern is returned. If the pattern is before the first element or the list is │
              empty, -1 is returned.  This option implies -sorted and cannot be used with  either │
              -all or -not.

   NESTED LIST OPTIONS
       These options are used to search lists of lists.  They may be used with any other options.

       -index indexList
              This  option is designed for use when searching within nested lists.  The indexList
              argument gives a path of indices (much as might be used with  the  lindex  or  lset
              commands)  within  each  element  to  allow  the location of the term being matched
              against.

       -subindices
              If this option is given, the index result from this command (or every index  result
              when  -all is also specified) will be a complete path (suitable for use with lindex
              or lset) within the overall list to the term found.   This  option  has  no  effect
              unless the -index is also specified, and is just a convenience short-cut.

EXAMPLES

       Basic searching:

              lsearch {a b c d e} c
                     2
              lsearch -all {a b c a b c} c
                     2 5

       Using lsearch to filter lists:

              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

       This can even do a “set-like” removal operation:

              lsearch -all -inline -not -exact {a b c a d e a f g a} a
                     b c d e f g

       Searching may start part-way through the list:

              lsearch -start 3 {a b c a b c} c
                     5

       It is also possible to search inside elements:

              lsearch -index 1 -all -inline {{a abc} {b bcd} {c cde}} *bc*
                     {a abc} {b bcd}

SEE ALSO

       foreach(3tcl),  list(3tcl),  lappend(3tcl),  lindex(3tcl),  linsert(3tcl),  llength(3tcl),
       lset(3tcl), lsort(3tcl), lrange(3tcl), lreplace(3tcl), string(3tcl)

KEYWORDS

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