string(3Tcl)

NAME
     string - Manipulate strings

SYNOPSIS
     string option arg ?arg ...?


DESCRIPTION
     Performs one of several string operations, depending on option.  The
     legal options (which may be abbreviated) are:

     string compare string1 string2
          Perform a character-by-character comparison of strings string1 and
          string2 in the same way as the C strcmp procedure.  Return -1, 0, or
          1, depending on whether string1 is lexicographically less than,
          equal to, or greater than string2.

     string first string1 string2
          Search string2 for a sequence of characters that exactly match the
          characters in string1.  If found, return the index of the first
          character in the first such match within string2.  If not found,
          return -1.

     string index string charIndex
          Returns the charIndex'th character of the string argument.  A
          charIndex of 0 corresponds to the first character of the string.  If
          charIndex is less than 0 or greater than or equal to the length of
          the string then an empty string is returned.

     string last string1 string2
          Search string2 for a sequence of characters that exactly match the
          characters in string1.  If found, return the index of the first
          character in the last such match within string2.  If there is no
          match, then return -1.

     string length string
          Returns a decimal string giving the number of characters in string.

     string match pattern string
          See if pattern matches string; return 1 if it does, 0 if it doesn't.
          Matching is done in a fashion similar to that used by the C-shell.
          For the two strings to match, their contents must be identical
          except that the following special sequences may appear in pattern:

          *         Matches any sequence of characters in string, including a
                    null string.

          ?         Matches any single character in string.

          [chars]   Matches any character in the set given by chars.  If a
                    sequence of the form x-y appears in chars, then any
                    character between x and y, inclusive, will match.
          \x        Matches the single character x.  This provides a way of
                    avoiding the special interpretation of the characters
                    *?[]\ in pattern.

     string range string first last
          Returns a range of consecutive characters from string, starting with
          the character whose index is first and ending with the character
          whose index is last.  An index of 0 refers to the first character of
          the string.  Last may be end (or any abbreviation of it) to refer to
          the last character of the string.  If first is less than zero then
          it is treated as if it were zero, and if last is greater than or
          equal to the length of the string then it is treated as if it were
          end.  If first is greater than last then an empty string is
          returned.

     string tolower string
          Returns a value equal to string except that all upper case letters
          have been converted to lower case.

     string toupper string
          Returns a value equal to string except that all lower case letters
          have been converted to upper case.

     string trim string ?chars?
          Returns a value equal to string except that any leading or trailing
          characters from the set given by chars are removed.  If chars is not
          specified then white space is removed (spaces, tabs, newlines, and
          carriage returns).

     string trimleft string ?chars?
          Returns a value equal to string except that any leading characters
          from the set given by chars are removed.  If chars is not specified
          then white space is removed (spaces, tabs, newlines, and carriage
          returns).

     string trimright string ?chars?
          Returns a value equal to string except that any trailing characters
          from the set given by chars are removed.  If chars is not specified
          then white space is removed (spaces, tabs, newlines, and carriage
          returns).

     string wordend string index
          Returns the index of the character just after the last one in the   |
          word containing character index of string.  A word is considered to |
          be any contiguous range of alphanumeric or underscore characters, or|
          any single character other than these.

     string wordstart string index
          Returns the index of the first character in the word containing     |
          character index of string.  A word is considered to be any          |
          contiguous range of alphanumeric or underscore characters, or any   |
          single character other than these.
KEYWORDS
     case conversion, compare, index, match, pattern, string, word