gcc -O -c psify.c
flex psify.lex
"psify.lex", line 276: warning, rule cannot be matched
"psify.lex", line 340: warning, rule cannot be matched
"psify.lex", line 341: warning, rule cannot be matched
gcc -O -c lex.yy.c
gcc  -o psify psify.o lex.yy.o