m4

# cat test.conf
define(`readconf',`ifelse($#,0,,`sinclude($1)readconf(shift($*))')')
readconf(translit(esyscmd(echo -n *.m4),` ',`,'))
# m4 -dtae test.conf
m4trace: -1- define(readconf, ifelse($#,0,,`sinclude($1)readconf(shift($*))'))
m4trace: -3- esyscmd(echo -n *.m4) -> aa.m4 bb.m4
m4trace: -2- translit(aa.m4 bb.m4,  , ,) -> aa.m4,bb.m4
m4trace: -1- readconf(aa.m4, bb.m4) -> ifelse(2,0,,`sinclude(aa.m4)readconf(shift(aa.m4,bb.m4))')
m4trace: -1- ifelse(2, 0, , sinclude(aa.m4)readconf(shift(aa.m4,bb.m4))) -> sinclude(aa.m4)readconf(shift(aa.m4,bb.m4))
m4trace: -1- sinclude(aa.m4)
m4trace: -1- define(aa, foo)

m4trace: -2- shift(aa.m4, bb.m4) -> `bb.m4'
m4trace: -1- readconf(bb.m4) -> ifelse(1,0,,`sinclude(bb.m4)readconf(shift(bb.m4))')
m4trace: -1- ifelse(1, 0, , sinclude(bb.m4)readconf(shift(bb.m4))) -> sinclude(bb.m4)readconf(shift(bb.m4))
m4trace: -1- sinclude(bb.m4)
m4trace: -1- define(bb, bar)

m4trace: -2- shift(bb.m4)
m4trace: -1- readconf() -> ifelse(1,0,,`sinclude()readconf(shift())')
m4trace: -1- ifelse(1, 0, , sinclude()readconf(shift())) -> sinclude()readconf(shift())
m4trace: -1- sinclude()
m4trace: -2- shift()
m4trace: -1- readconf() -> ifelse(1,0,,`sinclude()readconf(shift())')
m4trace: -1- ifelse(1, 0, , sinclude()readconf(shift())) -> sinclude()readconf(shift())
m4trace: -1- sinclude()
m4trace: -2- shift()
m4trace: -1- readconf() -> ifelse(1,0,,`sinclude()readconf(shift())')
m4trace: -1- ifelse(1, 0, , sinclude()readconf(shift())) -> sinclude()readconf(shift())
m4trace: -1- sinclude()
m4trace: -2- shift()
m4trace: -1- readconf() -> ifelse(1,0,,`sinclude()readconf(shift())')
m4trace: -1- ifelse(1, 0, , sinclude()readconf(shift())) -> sinclude()readconf(shift())
...
#

вот такая вот фигня... :(