Plan 9 from Bell Labs’s /usr/web/sources/contrib/gabidiaz/root/sys/src/cmd/perl/h2pl/getioctlsizes
#!/usr/bin/perl open (IOCTLS,'/usr/include/sys/ioctl.h') || die "ioctl open failed"; while (<IOCTLS>) { if (/^\s*#\s*define\s+\w+\s+_IO(R|W|WR)\('?\w+'?,\s*\w+,\s*([^)]+)/) { $need{$2}++; } } foreach $key ( sort keys %need ) { print $key,"\n"; }