tcl7.6 User Commands - string






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  argu-
          ment.   A charIndex of 0 corresponds to the first char-
          acter 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  charac-
          ters 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  pro-
                    vides a way of avoiding the special interpre-
                    tation 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. An
          index of end (or any abbreviation of it) refers 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  trail-
          ing 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 con-
          sidered 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