chdir $srcdir or die "$srcdir: $!";
opendir SRCDIR, "." or die "$srcdir: $!";
for (grep (/\.[ch]$/, readdir (SRCDIR))) { $exists{$_} = 1; }
closedir SRCDIR;
chdir $srcdir or die "$srcdir: $!";
opendir SRCDIR, "." or die "$srcdir: $!";
for (grep (/\.[ch]$/, readdir (SRCDIR))) { $exists{$_} = 1; }
closedir SRCDIR;