strace netstat -nlpt

root@oscar ~> strace netstat -an
execve("/bin/netstat", ["netstat", "-an"], [/* 24 vars */]) = 0
brk(0)                                  = 0xfff000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f4d54e3a000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=17362, ...}) = 0
mmap(NULL, 17362, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f4d54e35000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\20\31\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1732912, ...}) = 0
mmap(NULL, 3845248, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f4d5486f000
mprotect(0x7f4d54a10000, 2097152, PROT_NONE) = 0
mmap(0x7f4d54c10000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1a1000) = 0x7f4d54c10000
mmap(0x7f4d54c16000, 15488, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f4d54c16000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f4d54e34000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f4d54e33000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f4d54e32000
arch_prctl(ARCH_SET_FS, 0x7f4d54e33700) = 0
mprotect(0x7f4d54c10000, 16384, PROT_READ) = 0
mprotect(0x7f4d54e3b000, 4096, PROT_READ) = 0
munmap(0x7f4d54e35000, 17362)           = 0
brk(0)                                  = 0xfff000
brk(0x1020000)                          = 0x1020000
open("/usr/lib64/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=115934000, ...}) = 0
mmap(NULL, 115934000, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f4d4d9de000
close(3)                                = 0
open("/usr/share/locale/locale.alias", O_RDONLY|O_CLOEXEC) = 3
fcntl(3, F_GETFD)                       = 0x1 (flags FD_CLOEXEC)
fstat(3, {st_mode=S_IFREG|0644, st_size=2868, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f4d54e39000
read(3, "# Locale name alias data base.\n#"..., 4096) = 2868
read(3, "", 4096)                       = 0
close(3)                                = 0
munmap(0x7f4d54e39000, 4096)            = 0
open("/usr/share/locale/pl_PL.UTF-8/LC_MESSAGES/net-tools.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/pl_PL.utf8/LC_MESSAGES/net-tools.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/pl_PL/LC_MESSAGES/net-tools.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/pl.UTF-8/LC_MESSAGES/net-tools.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/pl.utf8/LC_MESSAGES/net-tools.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/pl/LC_MESSAGES/net-tools.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 0), ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f4d54e39000
write(1, "Active Internet connections (ser"..., 54Active Internet connections (servers and established)
) = 54
write(1, "Proto Recv-Q Send-Q Local Addres"..., 80Proto Recv-Q Send-Q Local Address           Foreign Address         State
) = 80
socket(PF_NETLINK, SOCK_RAW, 4)         = 3
sendmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000}, msg_iov(1)=[{"L\0\0\0\22\0\1\3@\342\1\0\0\0\0\0\2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 76}], msg_controllen=0, msg_flags=0}, 0) = 76
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000}, msg_iov(1)=[{"`\0\0\0\2\0\0\0@\342\1\0\206u\0\0\241\377\377\377L\0\0\0\22\0\1\3@\342\1\0"..., 8192}], msg_controllen=0, msg_flags=0}, 0) = 96
close(3)                                = 0
exit_group(-1)                          = ?
root@oscar ~>