cconcat is one of many Tclx commands.

cconcat ?string1? ?string2? ?...?

Concatenate the arguments, returning the resulting string. While string concatenation is normally performed by the parser, it is occasionally useful to have a command that returns a string. The is generally useful when a command to evaluate is required. No separators are inserted between the strings.

This command is UTF-aware.

An example of the use of this would be

package require Tclx
set cstring [cconcat abc [glob xyz.tcl]]

which might produce output such as


A minimal pure-Tcl substitute would be

proc cconcat args {join $args ""} ;# RS

See also string concat for contemplations about adding this functionality as a subcommand of string.