tn_setmode
{ "isig", "Enable signal trapping", tn_setmode, 1, MODE_TRAPSIG },
{ "+isig", 0, tn_setmode, 1, MODE_TRAPSIG },
{ "edit", "Enable character editing", tn_setmode, 1, MODE_EDIT },
{ "+edit", 0, tn_setmode, 1, MODE_EDIT },
{ "softtabs", "Enable tab expansion", tn_setmode, 1, MODE_SOFT_TAB },
{ "+softtabs", 0, tn_setmode, 1, MODE_SOFT_TAB },
{ "litecho", "Enable literal character echo", tn_setmode, 1, MODE_LIT_ECHO },
{ "+litecho", 0, tn_setmode, 1, MODE_LIT_ECHO },