TCL - String comparisons - compare match first last wordend

There are 6 string subcommands that do pattern and string matching. These are relatively fast operations, certainly faster than regular expressions, albeit less powerful.

string compare string1 string2

Compares string1 to string2 and returns:

• -1 ..... If string1 is less than string2
• 0 ........ If string1 is equal to string2
• 1 ........ If string1 is greater than string2

These comparisons are done alphabetically, not numerically - in other words "a" is less than "b", and "10" is less than "2".

string first string1 string2

Returns the index of the character in string1 that starts the first match to string2, or -1 if there is no match.

string last string1 string2

Returns the index of the character in string1 that starts the last match to string2, or -1 if there is no match.

string wordend string index

Returns the index of the character just after the last one in the word which contains the index'th character ofstring. A word is any contiguous set of letters, numbers or underscore characters, or a single other character.

string wordstart string index

Returns the index of the first character in the word that contains the index'th character of string. A word is any contiguous set of letters, numbers or underscore characters, or a single other character.

string match pattern string

Returns 1 if the pattern matches string. The pattern is a glob style pattern.

---

Example

set fullpath "/usr/home/clif/TCL_STUFF/TclTutor/Lsn.17"
set relativepath "CVS/Entries"

set paths [list $fullpath $re
set directorypath "/usr/bin/"

lativepath $directorypath]


h]
    set last [strin
foreach path $paths  {
    set first [string first "/" $pa
tg last "/" $path]

    # Report whether path is absolute or relative


se {
        puts "$pa
if {$first != 0} {
        puts "$path is a relative path"
    } e
lth is an absolute path"
    }


racter in $path, report the last word.
    # else, remove the last "/"
# If "/" is not the last ch
a, and find the next to last "/", and
    #   report the last word.

    incr last

t end]
        puts "The file referenced 
if {$last != [string length $path]} {
        set name [string range $path $la
sin $path is $name"
    } else {
        incr last -2;
        set tmp [string range $path 0 $last]

 end]
        puts "The final directory
set last [string last "/" $tmp]
        incr last;
        set name [string range $tmp $las
t in $path is $name"
    }

    # CVS is a directory created by the CVS source code control system.
    #



    # Compare to "a" to determine whet
if {[string match "*CVS*" $path]} {
        puts "$path is part of the source code control tree"
    }

n >= 0} {
        puts "$name starts with
her the first char is upper or lower case
    set comparison [string  compare $name "a"]
    if {$comparis
o a lowercase letter\n"
    } else {
        puts "$name starts with an uppercase letter\n"
    }


}