Manual Pages for UNIX Operating System command usage for man lindex

Tcl Built-In Commands                                  lindex(1T)



_________________________________________________________________

NAME
     lindex - Retrieve an element from a list

SYNOPSIS
     lindex list ?index...?
_________________________________________________________________

DESCRIPTION
     The lindex command  accepts  a  parameter,  list,  which  it  |
     treats  as  a Tcl list. It also accepts zero or more indices  |
     into the list.  The indices may be presented either consecu-  |
     tively  on  the  command  line, or grouped in a Tcl list and  |
     presented as a single argument.                               |

     If no indices are presented, the command takes the form:      |
          lindex list                                              |
     or                                                            |
          lindex list {}                                           |
     In this case, the return value of lindex is simply the value  |
     of the list parameter.                                        |

     When presented with  a  single  index,  the  lindex  command  |
     treats  list  as a Tcl list and returns the index'th element
     from it (0 refers to the first element  of  the  list).   In
     extracting  the element, lindex observes the same rules con-
     cerning braces and quotes and backslashes as the Tcl command
     interpreter; however, variable substitution and command sub-
     stitution do not occur.  If index  is  negative  or  greater
     than  or  equal  to the number of elements in value, then an
     empty string is returned.  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 additional index arguments are supplied, then each  argu-  |
     ment  is used in turn to select an element from the previous  |
     indexing operation, allowing the script to  select  elements  |
     from sublists.  The command,                                  |
          lindex $a 1 2 3                                          |
     or                                                            |
          lindex $a {1 2 3}                                        |
     is synonymous with                                            |
          lindex [lindex [lindex $a 1] 2] 3                        |

EXAMPLES                                                           |
          lindex {a b c}  => a b c                                 |
          lindex {a b c} {} => a b c                               |
          lindex {a b c} 0 => a                                    |
          lindex {a b c} 2 => c                                    |
          lindex {a b c} end => c                                  |



Tcl                     Last change: 8.4                        1






Tcl Built-In Commands                                  lindex(1T)



          lindex {a b c} end-1 => b                                |
          lindex {{a b c} {d e f} {g h i}} 2 1 => h                |
          lindex {{a b c} {d e f} {g h i}} {2 1} => h              |
          lindex {{{a b} {c d}} {{e f} {g h}}} 1 1 0 => g          |
          lindex {{{a b} {c d}} {{e f} {g h}}} {1 1 0} => g        |

SEE ALSO
     list(1T),     lappend(1T),     linsert(1T),     llength(1T),
     lsearch(1T), lset(1T), lsort(1T), lrange(1T), lreplace(1T)    |


KEYWORDS
     element, index, list

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     _______________________________________
    |   ATTRIBUTE TYPE   |  ATTRIBUTE VALUE|
    |____________________|__________________|_
    | Availability       |  runtime/tcl-8  |
    |____________________|__________________|_
    | Interface Stability|  Uncommitted    |
    |____________________|_________________|

NOTES
     Source for Tcl is available on http://opensolaris.org.



























Tcl                     Last change: 8.4                        2