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 string2string1 to string2 and returns:
string1 is less than string2string1 is equal to
string2string1 is greater than
string2string first string1 string2string1 that starts the first match to string2, or -1 if there is no match.string last string1 string2string1 that starts the last match to string2, or -1 if there is no match.string wordend string indexindex'th
character of string. A word is any
contiguous set of letters, numbers or underscore characters, or a
single other character.string wordstart string indexindex'th
character of string. A word is any
contiguous set of letters, numbers or underscore characters, or a
single other character.string match pattern stringpattern matches string. The pattern is
a glob style pattern.
set fullpath "/usr/home/clif/TCL_STUFF/TclTutor/Lsn.17"
set relativepath "CVS/Entries"
set directorypath "/usr/bin/"
set paths [list $fullpath $relativepath $directorypath]
foreach path $paths {
set first [string first "/" $path]
set last [string last "/" $path]
# Report whether path is absolute or relative
if {$first != 0} {
puts "$path is a relative path"
} else {
puts "$path is an absolute path"
}
# If "/" is not the last character in $path, report the last word.
# else, remove the last "/", and find the next to last "/", and
# report the last word.
incr last
if {$last != [string length $path]} {
set name [string range $path $last end]
puts "The file referenced in $path is $name"
} else {
incr last -2;
set tmp [string range $path 0 $last]
set last [string last "/" $tmp]
incr last;
set name [string range $tmp $last end]
puts "The final directory in $path is $name"
}
# CVS is a directory created by the CVS source code control system.
#
if {[string match "*CVS*" $path]} {
puts "$path is part of the source code control tree"
}
# Compare to "a" to determine whether the first char is upper or lower case
set comparison [string compare $name "a"]
if {$comparison >= 0} {
puts "$name starts with a lowercase letter\n"
} else {
puts "$name starts with an uppercase letter\n"
}
}