strace sz xx
execve("/usr/bin/sz", ["sz", "xx"], [/* 33 vars */]) = 0
brk(0)                                  = 0x9c5000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f6bd0d12000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/usr/local/lib/tls/x86_64/libnsl.so.1", O_RDONLY) = -1 ENOENT (No such file or directory)
stat("/usr/local/lib/tls/x86_64", 0x7fff3fefc590) = -1 ENOENT (No such file or directory)
open("/usr/local/lib/tls/libnsl.so.1", O_RDONLY) = -1 ENOENT (No such file or directory)
stat("/usr/local/lib/tls", 0x7fff3fefc590) = -1 ENOENT (No such file or directory)
open("/usr/local/lib/x86_64/libnsl.so.1", O_RDONLY) = -1 ENOENT (No such file or directory)
stat("/usr/local/lib/x86_64", 0x7fff3fefc590) = -1 ENOENT (No such file or directory)
open("/usr/local/lib/libnsl.so.1", O_RDONLY) = -1 ENOENT (No such file or directory)
stat("/usr/local/lib", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
open("tls/x86_64/libnsl.so.1", O_RDONLY) = -1 ENOENT (No such file or directory)
open("tls/libnsl.so.1", O_RDONLY)       = -1 ENOENT (No such file or directory)
open("x86_64/libnsl.so.1", O_RDONLY)    = -1 ENOENT (No such file or directory)
open("libnsl.so.1", O_RDONLY)           = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=68752, ...}) = 0
mmap(NULL, 68752, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f6bd0d01000
close(3)                                = 0
open("/lib64/libnsl.so.1", O_RDONLY)    = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0p@\300\235<\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=116368, ...}) = 0
mmap(0x3c9dc00000, 2198192, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3c9dc00000
mprotect(0x3c9dc16000, 2093056, PROT_NONE) = 0
mmap(0x3c9de15000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x15000) = 0x3c9de15000
mmap(0x3c9de17000, 6832, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3c9de17000
close(3)                                = 0
open("/usr/local/lib/libc.so.6", O_RDONLY) = -1 ENOENT (No such file or directory)
open("tls/x86_64/libc.so.6", O_RDONLY)  = -1 ENOENT (No such file or directory)
open("tls/libc.so.6", O_RDONLY)         = -1 ENOENT (No such file or directory)
open("x86_64/libc.so.6", O_RDONLY)      = -1 ENOENT (No such file or directory)
open("libc.so.6", O_RDONLY)             = -1 ENOENT (No such file or directory)
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\360\355\201\234<\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922112, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f6bd0d00000
mmap(0x3c9c800000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3c9c800000
mprotect(0x3c9c989000, 2097152, PROT_NONE) = 0
mmap(0x3c9cb89000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3c9cb89000
mmap(0x3c9cb8e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3c9cb8e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f6bd0cff000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f6bd0cfe000
arch_prctl(ARCH_SET_FS, 0x7f6bd0cff700) = 0
mprotect(0x3c9de15000, 4096, PROT_READ) = 0
mprotect(0x3c9cb89000, 16384, PROT_READ) = 0
mprotect(0x3c9c21f000, 4096, PROT_READ) = 0
munmap(0x7f6bd0d01000, 68752)           = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 13), ...}) = 0
fstat(2, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 13), ...}) = 0
brk(0)                                  = 0x9c5000
brk(0x9e6000)                           = 0x9e6000
open("/usr/lib/locale/locale-archive", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=99158576, ...}) = 0
mmap(NULL, 99158576, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f6bcae6d000
close(3)                                = 0
) = 21
      open("xx", O_RDONLY)                    = 3
                                                 fstat(3, {st_mode=S_IFREG|0664, st_size=0, ...}) = 0
                                                                                                     rt_sigaction(SIGALRM, {0x4081b0, [ALRM], SA_RESTORER, 0x3c9c832920}, {SIG_DFL, [], SA_RESTORER, 0x3c9c832920}, 8) = 0
                                              alarm(10)                               = 0
                                                                                         read(0, "30B01000000039a32\215\212\21", 128) = 21
                                                                                                                                          alarm(0)                                = 6
         rt_sigaction(SIGINT, {SIG_IGN, [INT], SA_RESTORER|SA_RESTART, 0x3c9c832920}, {0x4023e0, [INT], SA_RESTORER|SA_RESTART, 0x3c9c832920}, 8) = 0
                                                                                                                                                     ioctl(0, SNDCTL_TMR_STOP or TCSETSW, {B38400 -opost -isig -icanon -echo ...}) = 0
                                                          fstat(0, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 13), ...}) = 0
                                                                                                                             fstat(3, {st_mode=S_IFREG|0664, st_size=0, ...}) = 0
     fstat(3, {st_mode=S_IFREG|0664, st_size=0, ...}) = 0
                                                         write(1, "30A\4\0\0\0\0\) = 20, 10 
                                                                                       ioctl(0, TCSBRK, 0x1)                   = 0
                                                                                                                                  ioctl(0, TCFLSH, 0x2)                   = 0
 ioctl(0, SNDCTL_TMR_STOP or TCSETSW, {B38400 opost isig icanon echo ...}) = 0
ioctl(0, TCXONC, TCOON)                 = 0
exit_group(128)                         = ?