output of `strace ls`

strace_example

ubuntu@ip-172-31-40-117:~$ strace ls
execve("/bin/ls", ["ls"], [/* 19 vars */]) = 0
brk(0)                                  = 0x67c000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f525ac75000
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=22763, ...}) = 0
mmap(NULL, 22763, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f525ac6f000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libselinux.so.1", 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\20T\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=121936, ...}) = 0
mmap(NULL, 2221680, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f525a836000
mprotect(0x7f525a853000, 2093056, PROT_NONE) = 0
mmap(0x7f525aa52000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1c000) = 0x7f525aa52000
mmap(0x7f525aa54000, 1648, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f525aa54000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/librt.so.1", 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\340!\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=31752, ...}) = 0
mmap(NULL, 2128984, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f525a62e000
mprotect(0x7f525a635000, 2093056, PROT_NONE) = 0
mmap(0x7f525a834000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x6000) = 0x7f525a834000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libacl.so.1", 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\0P\33\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=31096, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f525ac6e000
mmap(NULL, 2126312, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f525a426000
mprotect(0x7f525a42d000, 2093056, PROT_NONE) = 0
mmap(0x7f525a62c000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x6000) = 0x7f525a62c000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/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\200\30\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1815224, ...}) = 0
mmap(NULL, 3929304, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f525a066000
mprotect(0x7f525a21b000, 2097152, PROT_NONE) = 0
mmap(0x7f525a41b000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1b5000) = 0x7f525a41b000
mmap(0x7f525a421000, 17624, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f525a421000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libdl.so.2", 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\340\r\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=14768, ...}) = 0
mmap(NULL, 2109704, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f5259e62000
mprotect(0x7f5259e64000, 2097152, PROT_NONE) = 0
mmap(0x7f525a064000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2000) = 0x7f525a064000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libpthread.so.0", 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\200l\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=135366, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f525ac6d000
mmap(NULL, 2212904, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f5259c45000
mprotect(0x7f5259c5d000, 2093056, PROT_NONE) = 0
mmap(0x7f5259e5c000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x17000) = 0x7f5259e5c000
mmap(0x7f5259e5e000, 13352, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f5259e5e000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libattr.so.1", 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\340\17\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=18552, ...}) = 0
mmap(NULL, 2113736, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f5259a40000
mprotect(0x7f5259a44000, 2093056, PROT_NONE) = 0
mmap(0x7f5259c43000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7f5259c43000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f525ac6c000
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f525ac6a000
arch_prctl(ARCH_SET_FS, 0x7f525ac6a7c0) = 0
mprotect(0x7f525a41b000, 16384, PROT_READ) = 0
mprotect(0x7f5259c43000, 4096, PROT_READ) = 0
mprotect(0x7f5259e5c000, 4096, PROT_READ) = 0
mprotect(0x7f525a064000, 4096, PROT_READ) = 0
mprotect(0x7f525a62c000, 4096, PROT_READ) = 0
mprotect(0x7f525a834000, 4096, PROT_READ) = 0
mprotect(0x7f525aa52000, 4096, PROT_READ) = 0
mprotect(0x618000, 4096, PROT_READ)     = 0
mprotect(0x7f525ac77000, 4096, PROT_READ) = 0
munmap(0x7f525ac6f000, 22763)           = 0
set_tid_address(0x7f525ac6aa90)         = 13999
set_robust_list(0x7f525ac6aaa0, 0x18)   = 0
futex(0x7fffd5be82fc, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME, 1, NULL, 7f525ac6a7c0) = -1 EAGAIN (Resource temporarily unavailable)
rt_sigaction(SIGRTMIN, {0x7f5259c4b750, [], SA_RESTORER|SA_SIGINFO, 0x7f5259c54cb0}, NULL, 8) = 0
rt_sigaction(SIGRT_1, {0x7f5259c4b7e0, [], SA_RESTORER|SA_RESTART|SA_SIGINFO, 0x7f5259c54cb0}, NULL, 8) = 0
rt_sigprocmask(SIG_UNBLOCK, [RTMIN RT_1], NULL, 8) = 0
getrlimit(RLIMIT_STACK, {rlim_cur=8192*1024, rlim_max=RLIM_INFINITY}) = 0
statfs("/selinux", {f_type="EXT2_SUPER_MAGIC", f_bsize=4096, f_blocks=2580302, f_bfree=2071292, f_bavail=1940223, f_files=655360, f_ffree=582850, f_fsid={176746833, 672429856}, f_namelen=255, f_frsize=4096}) = 0
brk(0)                                  = 0x67c000
brk(0x69d000)                           = 0x69d000
open("/proc/filesystems", O_RDONLY)     = 3
fstat(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f525ac74000
read(3, "nodev\tsysfs\nnodev\trootfs\nnodev\tb"..., 1024) = 313
read(3, "", 1024)                       = 0
close(3)                                = 0
munmap(0x7f525ac74000, 4096)            = 0
open("/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=1607664, ...}) = 0
mmap(NULL, 1607664, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f525aae1000
close(3)                                = 0
ioctl(1, SNDCTL_TMR_TIMEBASE or TCGETS, {B38400 opost isig icanon echo ...}) = 0
ioctl(1, TIOCGWINSZ, {ws_row=56, ws_col=180, ws_xpixel=0, ws_ypixel=0}) = 0
openat(AT_FDCWD, ".", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 3
getdents(3, /* 20 entries */, 32768)    = 656
getdents(3, /* 0 entries */, 32768)     = 0
close(3)                                = 0
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) = 0x7f525ac74000
write(1, "metrics  node_modules  npm-www.b"..., 115metrics  node_modules  npm-www.box  registry.replication  skimdb-aws  THIS_IS_SKIMDB_AWS_5  tmp  users.replication
) = 115
close(1)                                = 0
munmap(0x7f525ac74000, 4096)            = 0
close(2)                                = 0
exit_group(0)                           = ?
ubuntu@ip-172-31-40-117:~$