当前位置： 文江博客话题详情

共享库有什么作用以及为什么 ls 需要加载这么多？

发布于 2025-01-19 07:24:16 字数 8072 浏览 2 评论 0原文

我一直在LS命令上使用Strace，并且在下面遇到了大部分文本，并且在进行一些研究时，我发现其中的绝大多数是加载或阅读共享库。我的问题是，从简单的初学者术语中，共享库是什么，如果最后几行完成了我们需要做的一切，为什么LS需要这么多？

对于上下文，我试图解释从被要求到终止的简单过程。

execve("/usr/bin/ls", ["ls"], 0x7ffeaa5999c0 /* 49 vars */) = 0
brk(NULL)                               = 0x5616fe4fa000
arch_prctl(0x3001 /* ARCH_??? */, 0x7ffc4fdc9040) = -1 EINVAL (Invalid argument)
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=58140, ...}) = 0
mmap(NULL, 58140, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f25a2a11000
close(3)                                = 0
openat(AT_FDCWD, "/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@p\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=163200, ...}) = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f25a2a0f000
mmap(NULL, 174600, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f25a29e4000
mprotect(0x7f25a29ea000, 135168, PROT_NONE) = 0
mmap(0x7f25a29ea000, 102400, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x6000) = 0x7f25a29ea000
mmap(0x7f25a2a03000, 28672, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1f000) = 0x7f25a2a03000 
mmap(0x7f25a2a0b000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x26000) = 0x7f25a2a0b000 
mmap(0x7f25a2a0d000, 6664, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f25a2a0d000
close(3)                                = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\360A\2\0\0\0\0\0"..., 832) = 832
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
pread64(3, "\4\0\0\0\20\0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0", 32, 848) = 32
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\237\333t\347\262\27\320l\223\27*\202C\370T\177"..., 68, 880) = 68
fstat(3, {st_mode=S_IFREG|0755, st_size=2029560, ...}) = 0
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
pread64(3, "\4\0\0\0\20\0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0", 32, 848) = 32
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\237\333t\347\262\27\320l\223\27*\202C\370T\177"..., 68, 880) = 68
mmap(NULL, 2037344, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f25a27f2000
mmap(0x7f25a2814000, 1540096, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x22000) = 0x7f25a2814000 
mmap(0x7f25a298c000, 319488, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x19a000) = 0x7f25a298c000 
mmap(0x7f25a29da000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1e7000) = 0x7f25a29da000 
mmap(0x7f25a29e0000, 13920, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f25a29e0000
close(3)                                = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libpcre2-8.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\340\"\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=584392, ...}) = 0
mmap(NULL, 586536, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f25a2762000
mmap(0x7f25a2764000, 409600, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2000) = 0x7f25a2764000 
mmap(0x7f25a27c8000, 163840, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x66000) = 0x7f25a27c8000 
mmap(0x7f25a27f0000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x8d000) = 0x7f25a27f0000 
close(3)                                = 0
openat(AT_FDCWD, "/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 \22\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=18816, ...}) = 0
mmap(NULL, 20752, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f25a275c000
mmap(0x7f25a275d000, 8192, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1000) = 0x7f25a275d000 
mmap(0x7f25a275f000, 4096, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7f25a275f000 
mmap(0x7f25a2760000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7f25a2760000 
close(3)                                = 0
openat(AT_FDCWD, "/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\220q\0\0\0\0\0\0"..., 832) = 832
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\360\2300%\360\340\363'\246\332u/\364\377\246u"..., 68, 824) = 68
fstat(3, {st_mode=S_IFREG|0755, st_size=157224, ...}) = 0
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\360\2300%\360\340\363'\246\332u/\364\377\246u"..., 68, 824) = 68
mmap(NULL, 140408, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f25a2739000
mmap(0x7f25a273f000, 69632, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x6000) = 0x7f25a273f000 
mmap(0x7f25a2750000, 24576, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x17000) = 0x7f25a2750000 
mmap(0x7f25a2756000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1c000) = 0x7f25a2756000 
mmap(0x7f25a2758000, 13432, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f25a2758000
close(3)                                = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f25a2737000
arch_prctl(ARCH_SET_FS, 0x7f25a2738400) = 0 mprotect(0x7f25a29da000, 16384, PROT_READ) = 0 mprotect(0x7f25a2756000, 4096, PROT_READ) = 0 
mprotect(0x7f25a2760000, 4096, PROT_READ) = 0 
mprotect(0x7f25a27f0000, 4096, PROT_READ) = 0 
mprotect(0x7f25a2a0b000, 4096, PROT_READ) = 0 mprotect(0x5616fca52000, 4096, PROT_READ) = 0 mprotect(0x7f25a2a4d000, 4096, PROT_READ) = 0
munmap(0x7f25a2a11000, 58140)           = 0 
set_tid_address(0x7f25a27386d0)         = 1376 
set_robust_list(0x7f25a27386e0, 24)     = 0
rt_sigaction(SIGRTMIN, {sa_handler=0x7f25a273fbf0, sa_mask=[], sa_flags=SA_RESTORER|SA_SIGINFO, sa_restorer=0x7f25a274d3c0}, NULL, 8) = 0
rt_sigaction(SIGRT_1, {sa_handler=0x7f25a273fc90, sa_mask=[], sa_flags=SA_RESTORER|SA_RESTART|SA_SIGINFO, sa_restorer=0x7f25a274d3c0}, NULL, 8) = 0
rt_sigprocmask(SIG_UNBLOCK, [RTMIN RT_1], NULL, 8) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
statfs("/sys/fs/selinux", 0x7ffc4fdc8f90) = -1 ENOENT (No such file or directory)
statfs("/selinux", 0x7ffc4fdc8f90)      = -1 ENOENT (No such file or directory)
brk(NULL)                               = 0x5616fe4fa000 
brk(0x5616fe51b000)                     = 0x5616fe51b000 
openat(AT_FDCWD, "/proc/filesystems", O_RDONLY|O_CLOEXEC) = 3 
fstat(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
read(3, "nodev\tsysfs\nnodev\ttmpfs\nnodev\tbd"..., 1024) = 360 
read(3, "", 1024)                       = 0 close(3)                                = 0
access("/etc/selinux/config", F_OK)     = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=5699248, ...}) = 0
mmap(NULL, 5699248, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f25a21c7000 
close(3)                                = 0
ioctl(1, TCGETS, {B38400 opost isig icanon echo ...}) = 0
ioctl(1, TIOCGWINSZ, {ws_row=24, ws_col=80, ws_xpixel=0, ws_ypixel=0}) = 0
openat(AT_FDCWD, ".", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 3 
fstat(3, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
getdents64(3, /* 20 entries */, 32768)  = 624 getdents64(3, /* 0 entries */, 32768)   = 0
close(3)                                = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(0x88, 0), ...}) = 0 
write(1, "Desktop  Documents  Downloads  M"..., 72Desktop  Documents  Downloads  Music  Pictures    Public    Templates  Videos ) = 72 
close(1)                                = 0 close(2)                                = 0
exit_group(0)                           = ? +++ exited with 0 +++
原文

I've been using strace on the ls command and I came across the large chunk of text below, and in doing a bit of research I've found that the vast majority of this is loading or reading shared libraries. My question is, in simple beginner terms, what are shared libraries and why does ls need so many if the final few lines completes all we need to do?

For context, I'm trying to explain what a simple process like ls does from being called upon to being terminated.

execve("/usr/bin/ls", ["ls"], 0x7ffeaa5999c0 /* 49 vars */) = 0
brk(NULL)                               = 0x5616fe4fa000
arch_prctl(0x3001 /* ARCH_??? */, 0x7ffc4fdc9040) = -1 EINVAL (Invalid argument)
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=58140, ...}) = 0
mmap(NULL, 58140, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f25a2a11000
close(3)                                = 0
openat(AT_FDCWD, "/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@p\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=163200, ...}) = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f25a2a0f000
mmap(NULL, 174600, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f25a29e4000
mprotect(0x7f25a29ea000, 135168, PROT_NONE) = 0
mmap(0x7f25a29ea000, 102400, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x6000) = 0x7f25a29ea000
mmap(0x7f25a2a03000, 28672, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1f000) = 0x7f25a2a03000 
mmap(0x7f25a2a0b000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x26000) = 0x7f25a2a0b000 
mmap(0x7f25a2a0d000, 6664, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f25a2a0d000
close(3)                                = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\360A\2\0\0\0\0\0"..., 832) = 832
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
pread64(3, "\4\0\0\0\20\0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0", 32, 848) = 32
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\237\333t\347\262\27\320l\223\27*\202C\370T\177"..., 68, 880) = 68
fstat(3, {st_mode=S_IFREG|0755, st_size=2029560, ...}) = 0
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
pread64(3, "\4\0\0\0\20\0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0", 32, 848) = 32
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\237\333t\347\262\27\320l\223\27*\202C\370T\177"..., 68, 880) = 68
mmap(NULL, 2037344, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f25a27f2000
mmap(0x7f25a2814000, 1540096, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x22000) = 0x7f25a2814000 
mmap(0x7f25a298c000, 319488, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x19a000) = 0x7f25a298c000 
mmap(0x7f25a29da000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1e7000) = 0x7f25a29da000 
mmap(0x7f25a29e0000, 13920, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f25a29e0000
close(3)                                = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libpcre2-8.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\340\"\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=584392, ...}) = 0
mmap(NULL, 586536, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f25a2762000
mmap(0x7f25a2764000, 409600, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2000) = 0x7f25a2764000 
mmap(0x7f25a27c8000, 163840, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x66000) = 0x7f25a27c8000 
mmap(0x7f25a27f0000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x8d000) = 0x7f25a27f0000 
close(3)                                = 0
openat(AT_FDCWD, "/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 \22\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=18816, ...}) = 0
mmap(NULL, 20752, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f25a275c000
mmap(0x7f25a275d000, 8192, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1000) = 0x7f25a275d000 
mmap(0x7f25a275f000, 4096, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7f25a275f000 
mmap(0x7f25a2760000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7f25a2760000 
close(3)                                = 0
openat(AT_FDCWD, "/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\220q\0\0\0\0\0\0"..., 832) = 832
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\360\2300%\360\340\363'\246\332u/\364\377\246u"..., 68, 824) = 68
fstat(3, {st_mode=S_IFREG|0755, st_size=157224, ...}) = 0
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\360\2300%\360\340\363'\246\332u/\364\377\246u"..., 68, 824) = 68
mmap(NULL, 140408, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f25a2739000
mmap(0x7f25a273f000, 69632, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x6000) = 0x7f25a273f000 
mmap(0x7f25a2750000, 24576, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x17000) = 0x7f25a2750000 
mmap(0x7f25a2756000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1c000) = 0x7f25a2756000 
mmap(0x7f25a2758000, 13432, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f25a2758000
close(3)                                = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f25a2737000
arch_prctl(ARCH_SET_FS, 0x7f25a2738400) = 0 mprotect(0x7f25a29da000, 16384, PROT_READ) = 0 mprotect(0x7f25a2756000, 4096, PROT_READ) = 0 
mprotect(0x7f25a2760000, 4096, PROT_READ) = 0 
mprotect(0x7f25a27f0000, 4096, PROT_READ) = 0 
mprotect(0x7f25a2a0b000, 4096, PROT_READ) = 0 mprotect(0x5616fca52000, 4096, PROT_READ) = 0 mprotect(0x7f25a2a4d000, 4096, PROT_READ) = 0
munmap(0x7f25a2a11000, 58140)           = 0 
set_tid_address(0x7f25a27386d0)         = 1376 
set_robust_list(0x7f25a27386e0, 24)     = 0
rt_sigaction(SIGRTMIN, {sa_handler=0x7f25a273fbf0, sa_mask=[], sa_flags=SA_RESTORER|SA_SIGINFO, sa_restorer=0x7f25a274d3c0}, NULL, 8) = 0
rt_sigaction(SIGRT_1, {sa_handler=0x7f25a273fc90, sa_mask=[], sa_flags=SA_RESTORER|SA_RESTART|SA_SIGINFO, sa_restorer=0x7f25a274d3c0}, NULL, 8) = 0
rt_sigprocmask(SIG_UNBLOCK, [RTMIN RT_1], NULL, 8) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
statfs("/sys/fs/selinux", 0x7ffc4fdc8f90) = -1 ENOENT (No such file or directory)
statfs("/selinux", 0x7ffc4fdc8f90)      = -1 ENOENT (No such file or directory)
brk(NULL)                               = 0x5616fe4fa000 
brk(0x5616fe51b000)                     = 0x5616fe51b000 
openat(AT_FDCWD, "/proc/filesystems", O_RDONLY|O_CLOEXEC) = 3 
fstat(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
read(3, "nodev\tsysfs\nnodev\ttmpfs\nnodev\tbd"..., 1024) = 360 
read(3, "", 1024)                       = 0 close(3)                                = 0
access("/etc/selinux/config", F_OK)     = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=5699248, ...}) = 0
mmap(NULL, 5699248, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f25a21c7000 
close(3)                                = 0
ioctl(1, TCGETS, {B38400 opost isig icanon echo ...}) = 0
ioctl(1, TIOCGWINSZ, {ws_row=24, ws_col=80, ws_xpixel=0, ws_ypixel=0}) = 0
openat(AT_FDCWD, ".", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 3 
fstat(3, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
getdents64(3, /* 20 entries */, 32768)  = 624 getdents64(3, /* 0 entries */, 32768)   = 0
close(3)                                = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(0x88, 0), ...}) = 0 
write(1, "Desktop  Documents  Downloads  M"..., 72Desktop  Documents  Downloads  Music  Pictures    Public    Templates  Videos ) = 72 
close(1)                                = 0 close(2)                                = 0
exit_group(0)                           = ? +++ exited with 0 +++

如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

扫码二维码加入Web技术交流群

发布评论

需要 登录 才能够评论， 你可以免费 注册 一个本站的账号。

评论（1）

摇划花蜜的午后 2025-01-26 07:24:16

用简单的初学者术语来说，什么是共享库

共享库允许

  1. 二进制文件共享公共代码，因此您不必在磁盘和 RAM 中存储 1000 多个单独的 printf 代码实例，并且
  2. 允许错误修复同时影响所有二进制文件。

(1) 过去，当磁盘大小为 10MiB，而 64KiB 的 RAM很多 时，这一点很重要，但现在这个原因的重要性已经减弱。

(2) 的重要性已显着增加——单个系统上有数千个二进制文件，将它们全部重建是不切实际的（如果不是共享库，则需要使错误修复生效）。

为什么 ls 需要这么多

它只使用很少库：libc.so.6、libdl.so.2和libpthread .so.0、libselinux.so.1 和 libpcre2-8.so.0。作为比较，firefox 或 google-chrome 使用 90+，而我使用的一些二进制文件使用 10,000+。

ls 不一定是一个简单的程序——它可以处理颜色，可以在多个语言环境中显示和排序文件名，等等。

in simple beginner terms, what are shared libraries

Shared libraries allow

  1. binaries to share common code, so you don't store 1000+ separate instances of printf code on disk and in RAM, and
  2. allow a bug fix to affect all binaries at once.

(1) used to be important when disks were 10MiB and 64KiB was a lot of RAM, but now this reason has diminished in importance.

The importance of (2) has dramatically increased -- with 1000s of binaries on a single system it's impractical to rebuild them all (which would be required for bug fix to take effect if not for shared libraries).

and why does ls need so many

It only uses few libraries: libc.so.6, libdl.so.2 and libpthread.so.0, libselinux.so.1 and libpcre2-8.so.0. For comparison, something like firefox or google-chrome use 90+, and some binaries I work with use 10,000+.

ls is not necessarily a simple program -- it can do color, it can display and sort file names in multiple locales, etc.

回复 原文
~没有更多了~

关于作者

征﹌骨岁月お

暂无简介

文章
评论
27 人气
发私信

相关话题

更多

热门标签

操作系统 程序设计 IT运维 Linux系统管理 JavaScript 服务器应用 solaris C/C++ PHP Shell BSD Vue.js aix Oracle Python HTML 系统管理 HTML5 CSS 前端
更多

推荐作者

alipaysp_snBf0MSZIv

文章 0 评论 0

梦断已成空

文章 0 评论 0

瞎闹

文章 0 评论 0

凯凯我们等你回来

文章 0 评论 0

寄意

文章 0 评论 0

似梦非梦

文章 0 评论 0

更多

友情链接

文江博客
    我们使用 Cookies 和其他技术来定制您的体验包括您的登录状态等。通过阅读我们的 隐私政策 了解更多相关信息。 单击 接受 或继续使用网站，即表示您同意使用 Cookies 和您的相关数据。
    原文