Split a line as if it were a command

cmdsplit.tcl

#!/usr/bin/env tclsh

# http://wiki.tcl.tk/21701
proc cmdSplit command {
    if {![info complete $command]} {error "non complete command"}
    set res ""; # the list of words
    set chunk ""
    foreach word [split $command " \t"] {
        # testing each word until the word being tested makes the
        # command up to it complete
        # example:
        # set "a b"
        # set -> complete, 1 word
        # set "a -> not complete
        # set "a b" -> complete, 2 words
        append chunk $word
        if {[info complete "$res $chunk\n"]} {
            lappend res $chunk
            set chunk ""
        } else {
            append chunk " "
        }
    }
    lsearch -inline -all -not $res {}   ;# empty words denote consecutive whitespace
}





proc proc_cmds { cmd } {
	set chan [open "old/${cmd}s-0.txt" r+]
	set cout [open "${cmd}s-1.txt" w]
	while { [gets $chan line] >= 0 } {	
		set  fields [cmdSplit $line]
		if { [lindex $fields 0] == $cmd } {
			set txt ["proc_$cmd" $fields]
			puts $cout $txt
		}
	}
	close $chan
	close $cout
}

proc proc_comm { fields } {
	# TODO destructing bind in gist
	lassign $fields cmd sym dn typ curr ticker desc
	return "comm\t$ticker\t$dn\t$typ\t$curr\t$desc"
}

proc proc_etran { fields } {
	lassign $fields cmd tax ds way acc sym qty amt
	set sym1 "$sym.L"
	set special [list AFUSO AUG AUS CRC CSAL FGF FGSS FSS HYH KEYS SHOS]
	if { [lsearch $special $sym] != -1 } { set sym1 $sym }
	set idxs [list FTAS]
	if { [lsearch idxs $sym] != -1 } { set sym1 "^$sym" }
	set sym2 $sym1
	return "etran $tax $ds $way $acc $sym2 $qty $amt"
}

proc proc_nacc { fields } {
	lassign $fields cmd dr cr typ m desc
	set dr1 [string map {"/" "_"} $dr]
	set cr1 [string map {"/" "_"} $cr]
	return "nacc $dr1\t$cr1\t$typ $m\t$desc"

}


proc proc_ntran { fields } {
	lassign $fields cmd ds dr cr amt cl desc
	return "ntran $ds $dr $cr\t$amt\t$desc"
}

proc_cmds comm
proc_cmds etran
proc_cmds nacc
proc_cmds ntran

#proc_comms

Taken from my file /mnt/vivo/home/mcarter/repos/redact/docs/accts2015/data/upgrade-1.tcl