$ gdb --args ./miniperl -e '*foo' (gdb) br Perl_gv_fetchpvn_flags Breakpoint 1 at 0x806c485: file gv.c, line 710. (gdb) condition 1 nambeg[0] == 'f' (gdb) run Starting program: /local/build/perl-current/miniperl -e \*foo [New Thread 1074334048 (LWP 2919)] [Switching to Thread 1074334048 (LWP 2919)] Breakpoint 1, Perl_gv_fetchpvn_flags (my_perl=0x8199720, nambeg=0x8199ca9 "foo", full_len=3, flags=1, sv_type=12) at gv.c:710 710 register const char *name = nambeg; (gdb) bt #0 Perl_gv_fetchpvn_flags (my_perl=0x8199720, nambeg=0x8199ca9 "foo", full_len=3, flags=1, sv_type=12) at gv.c:710 #1 0x0806c406 in Perl_gv_fetchpv (my_perl=0x8199720, nambeg=0x8199ca9 "foo", add=1, sv_type=12) at gv.c:696 #2 0x08087238 in S_pending_ident (my_perl=0x8199720) at toke.c:5669 #3 0x08076115 in Perl_yylex (my_perl=0x8199720) at toke.c:2431 #4 0x08092b5b in Perl_yyparse (my_perl=0x8199720) at perly.c:412 #5 0x08063ebc in S_parse_body (my_perl=0x8199720, env=0x0, xsinit=0x804bb65 ) at perl.c:2136 #6 0x08062d16 in perl_parse (my_perl=0x8199720, xsinit=0x804bb65 , argc=3, argv=0xbffff3f4, env=0x0) at perl.c:1542 #7 0x0804baeb in main (argc=3, argv=0xbffff3f4, env=0xbffff404) at miniperlmain.c:101 #8 0x42015704 in __libc_start_main () from /lib/tls/libc.so.6