user1424739's questions -ubuntu

user1424739

Asked: 2021-05-02 18:07:41 +0800 CST

Does ubuntu have elfdump?

1

https://docs.oracle.com/cd/E19683-01/816-0210/6m6nb7m8b/index.html

I see SunOS has elfdump. Does ubuntu have it as well? I can not find this command.

user1424739

Asked: 2021-03-24 07:41:38 +0800 CST

Where is the manpage of endsgent?

0

https://code.woboq.org/userspace/glibc/gshadow/gshadow.h.html

I don't find the manpage of endsgent. Does anybody know which package has the manpage for endsgent?

user1424739

Asked: 2021-03-19 16:45:05 +0800 CST

the raw command to compile `login`

0

I want to manually compile the login command (with the exact CC and LD commands).

https://packages.ubuntu.com/groovy/login

/tmp/shadow_4.8.1.orig/src$ make VERBOSE=1
  CC       login.o
  CCLD     login

The above command doesn't show the exact command. When I run the following, I see the following error.

$ gcc -o login login.c
login.c:33:10: fatal error: config.h: No such file or directory
   33 | #include <config.h>
      |          ^~~~~~~~~~
compilation terminated.

Could anybody show me how to get the exact commands used to compile the program login? Thanks.

user1424739

Asked: 2021-03-04 20:19:34 +0800 CST

About files in /usr/include/x86_64-linux-gnu

0

I see libc6-dev have files installed in /usr/include/x86_64-linux-gnu.

It seems that files in /usr/include/x86_64-linux-gnu/sys are pointed by symlinks from /usr/include/sys. And it seems that /usr/include/bits/ and /usr/include/x86_64-linux-gnu/bits have the same files.

Are /usr/include/x86_64-linux-gnu/sys and /usr/include/sys exactly the same?

Are /usr/include/bits and /usr/include/x86_64-linux-gnu/bits exactly the same?

$ ls -gG /usr/include/sys/wait.h
lrwxrwxrwx 1 30 2021/01/05-00:47:42 /usr/include/sys/wait.h -> ../x86_64-linux-gnu/sys/wait.h
$ ls /usr/include/sys/ | wc -l
82
$ ls /usr/include/x86_64-linux-gnu/sys/ | wc -l
82
$ cmp /usr/include/bits/a.out.h /usr/include/x86_64-linux-gnu/bits/a.out.h
$ ls /usr/include/bits/ | wc -l
172
$ ls /usr/include/x86_64-linux-gnu/bits/ | wc -l
172

What files are in the sys/ directory and what files are in the bits/ directory?

Which package installs files in /usr/include/bits? I can not find the package that installs for example the following file.

$ apt-file search /usr/include/bits/a.out.h

Why only fpu_control.h in x86_64-linux-gnu/ is linked to /usr/include/?

/usr/include$ ls -l a.out.h fpu_control.h  ieee754.h
ls: cannot access 'a.out.h': No such file or directory
ls: cannot access 'ieee754.h': No such file or directory
lrwxrwxrwx 1 root root 30 2021/01/05-00:47:42 fpu_control.h -> x86_64-linux-gnu/fpu_control.h

/usr/include/x86_64-linux-gnu/a.out.h
/usr/include/x86_64-linux-gnu/fpu_control.h
/usr/include/x86_64-linux-gnu/ieee754.h
/usr/include/x86_64-linux-gnu/bits/a.out.h
/usr/include/x86_64-linux-gnu/bits/argp-ldbl.h
/usr/include/x86_64-linux-gnu/bits/auxv.h
/usr/include/x86_64-linux-gnu/bits/byteswap.h
/usr/include/x86_64-linux-gnu/bits/cmathcalls.h
/usr/include/x86_64-linux-gnu/bits/confname.h
/usr/include/x86_64-linux-gnu/bits/cpu-set.h
/usr/include/x86_64-linux-gnu/bits/dirent.h
/usr/include/x86_64-linux-gnu/bits/dirent_ext.h
/usr/include/x86_64-linux-gnu/bits/dlfcn.h
/usr/include/x86_64-linux-gnu/bits/elfclass.h
/usr/include/x86_64-linux-gnu/bits/endian.h
/usr/include/x86_64-linux-gnu/bits/endianness.h
/usr/include/x86_64-linux-gnu/bits/environments.h
/usr/include/x86_64-linux-gnu/bits/epoll.h
/usr/include/x86_64-linux-gnu/bits/err-ldbl.h
/usr/include/x86_64-linux-gnu/bits/errno.h
/usr/include/x86_64-linux-gnu/bits/error-ldbl.h
/usr/include/x86_64-linux-gnu/bits/error.h
/usr/include/x86_64-linux-gnu/bits/eventfd.h
/usr/include/x86_64-linux-gnu/bits/fcntl-linux.h
/usr/include/x86_64-linux-gnu/bits/fcntl.h
/usr/include/x86_64-linux-gnu/bits/fcntl2.h
/usr/include/x86_64-linux-gnu/bits/fenv.h
/usr/include/x86_64-linux-gnu/bits/fenvinline.h
/usr/include/x86_64-linux-gnu/bits/floatn-common.h
/usr/include/x86_64-linux-gnu/bits/floatn.h
/usr/include/x86_64-linux-gnu/bits/flt-eval-method.h
/usr/include/x86_64-linux-gnu/bits/fp-fast.h
/usr/include/x86_64-linux-gnu/bits/fp-logb.h
/usr/include/x86_64-linux-gnu/bits/getopt_core.h
/usr/include/x86_64-linux-gnu/bits/getopt_ext.h
/usr/include/x86_64-linux-gnu/bits/getopt_posix.h
/usr/include/x86_64-linux-gnu/bits/hwcap.h
/usr/include/x86_64-linux-gnu/bits/in.h
/usr/include/x86_64-linux-gnu/bits/indirect-return.h
/usr/include/x86_64-linux-gnu/bits/initspin.h
/usr/include/x86_64-linux-gnu/bits/inotify.h
/usr/include/x86_64-linux-gnu/bits/ioctl-types.h
/usr/include/x86_64-linux-gnu/bits/ioctls.h
/usr/include/x86_64-linux-gnu/bits/ipc-perm.h
/usr/include/x86_64-linux-gnu/bits/ipc.h
/usr/include/x86_64-linux-gnu/bits/ipctypes.h
/usr/include/x86_64-linux-gnu/bits/iscanonical.h
/usr/include/x86_64-linux-gnu/bits/libc-header-start.h
/usr/include/x86_64-linux-gnu/bits/libm-simd-decl-stubs.h
/usr/include/x86_64-linux-gnu/bits/link.h
/usr/include/x86_64-linux-gnu/bits/local_lim.h
/usr/include/x86_64-linux-gnu/bits/locale.h
/usr/include/x86_64-linux-gnu/bits/long-double.h
/usr/include/x86_64-linux-gnu/bits/math-vector.h
/usr/include/x86_64-linux-gnu/bits/mathcalls-helper-functions.h
/usr/include/x86_64-linux-gnu/bits/mathcalls-narrow.h
/usr/include/x86_64-linux-gnu/bits/mathcalls.h
/usr/include/x86_64-linux-gnu/bits/mathdef.h
/usr/include/x86_64-linux-gnu/bits/mathinline.h
/usr/include/x86_64-linux-gnu/bits/mman-linux.h
/usr/include/x86_64-linux-gnu/bits/mman-map-flags-generic.h
/usr/include/x86_64-linux-gnu/bits/mman-shared.h
/usr/include/x86_64-linux-gnu/bits/mman.h
/usr/include/x86_64-linux-gnu/bits/monetary-ldbl.h
/usr/include/x86_64-linux-gnu/bits/mqueue.h
/usr/include/x86_64-linux-gnu/bits/mqueue2.h
/usr/include/x86_64-linux-gnu/bits/msq-pad.h
/usr/include/x86_64-linux-gnu/bits/msq.h
/usr/include/x86_64-linux-gnu/bits/netdb.h
/usr/include/x86_64-linux-gnu/bits/param.h
/usr/include/x86_64-linux-gnu/bits/poll.h
/usr/include/x86_64-linux-gnu/bits/poll2.h
/usr/include/x86_64-linux-gnu/bits/posix1_lim.h
/usr/include/x86_64-linux-gnu/bits/posix2_lim.h
/usr/include/x86_64-linux-gnu/bits/posix_opt.h
/usr/include/x86_64-linux-gnu/bits/printf-ldbl.h
/usr/include/x86_64-linux-gnu/bits/procfs-extra.h
/usr/include/x86_64-linux-gnu/bits/procfs-id.h
/usr/include/x86_64-linux-gnu/bits/procfs-prregset.h
/usr/include/x86_64-linux-gnu/bits/procfs.h
/usr/include/x86_64-linux-gnu/bits/pthreadtypes-arch.h
/usr/include/x86_64-linux-gnu/bits/pthreadtypes.h
/usr/include/x86_64-linux-gnu/bits/ptrace-shared.h
/usr/include/x86_64-linux-gnu/bits/resource.h
/usr/include/x86_64-linux-gnu/bits/sched.h
/usr/include/x86_64-linux-gnu/bits/select.h
/usr/include/x86_64-linux-gnu/bits/select2.h
/usr/include/x86_64-linux-gnu/bits/sem-pad.h
/usr/include/x86_64-linux-gnu/bits/sem.h
/usr/include/x86_64-linux-gnu/bits/semaphore.h
/usr/include/x86_64-linux-gnu/bits/setjmp.h
/usr/include/x86_64-linux-gnu/bits/setjmp2.h
/usr/include/x86_64-linux-gnu/bits/shm-pad.h
/usr/include/x86_64-linux-gnu/bits/shm.h
/usr/include/x86_64-linux-gnu/bits/shmlba.h
/usr/include/x86_64-linux-gnu/bits/sigaction.h
/usr/include/x86_64-linux-gnu/bits/sigcontext.h
/usr/include/x86_64-linux-gnu/bits/sigevent-consts.h
/usr/include/x86_64-linux-gnu/bits/siginfo-arch.h
/usr/include/x86_64-linux-gnu/bits/siginfo-consts-arch.h
/usr/include/x86_64-linux-gnu/bits/siginfo-consts.h
/usr/include/x86_64-linux-gnu/bits/signal_ext.h
/usr/include/x86_64-linux-gnu/bits/signalfd.h
/usr/include/x86_64-linux-gnu/bits/signum-generic.h
/usr/include/x86_64-linux-gnu/bits/signum.h
/usr/include/x86_64-linux-gnu/bits/sigstack.h
/usr/include/x86_64-linux-gnu/bits/sigthread.h
/usr/include/x86_64-linux-gnu/bits/sockaddr.h
/usr/include/x86_64-linux-gnu/bits/socket-constants.h
/usr/include/x86_64-linux-gnu/bits/socket.h
/usr/include/x86_64-linux-gnu/bits/socket2.h
/usr/include/x86_64-linux-gnu/bits/socket_type.h
/usr/include/x86_64-linux-gnu/bits/ss_flags.h
/usr/include/x86_64-linux-gnu/bits/stat.h
/usr/include/x86_64-linux-gnu/bits/statfs.h
/usr/include/x86_64-linux-gnu/bits/statvfs.h
/usr/include/x86_64-linux-gnu/bits/statx-generic.h
/usr/include/x86_64-linux-gnu/bits/statx.h
/usr/include/x86_64-linux-gnu/bits/stdint-intn.h
/usr/include/x86_64-linux-gnu/bits/stdint-uintn.h
/usr/include/x86_64-linux-gnu/bits/stdio-ldbl.h
/usr/include/x86_64-linux-gnu/bits/stdio.h
/usr/include/x86_64-linux-gnu/bits/stdio2.h
/usr/include/x86_64-linux-gnu/bits/stdio_lim.h
/usr/include/x86_64-linux-gnu/bits/stdlib-bsearch.h
/usr/include/x86_64-linux-gnu/bits/stdlib-float.h
/usr/include/x86_64-linux-gnu/bits/stdlib-ldbl.h
/usr/include/x86_64-linux-gnu/bits/stdlib.h
/usr/include/x86_64-linux-gnu/bits/string_fortified.h
/usr/include/x86_64-linux-gnu/bits/strings_fortified.h
/usr/include/x86_64-linux-gnu/bits/struct_mutex.h
/usr/include/x86_64-linux-gnu/bits/struct_rwlock.h
/usr/include/x86_64-linux-gnu/bits/sys_errlist.h
/usr/include/x86_64-linux-gnu/bits/syscall.h
/usr/include/x86_64-linux-gnu/bits/sysctl.h
/usr/include/x86_64-linux-gnu/bits/syslog-ldbl.h
/usr/include/x86_64-linux-gnu/bits/syslog-path.h
/usr/include/x86_64-linux-gnu/bits/syslog.h
/usr/include/x86_64-linux-gnu/bits/sysmacros.h
/usr/include/x86_64-linux-gnu/bits/termios-baud.h
/usr/include/x86_64-linux-gnu/bits/termios-c_cc.h
/usr/include/x86_64-linux-gnu/bits/termios-c_cflag.h
/usr/include/x86_64-linux-gnu/bits/termios-c_iflag.h
/usr/include/x86_64-linux-gnu/bits/termios-c_lflag.h
/usr/include/x86_64-linux-gnu/bits/termios-c_oflag.h
/usr/include/x86_64-linux-gnu/bits/termios-misc.h
/usr/include/x86_64-linux-gnu/bits/termios-struct.h
/usr/include/x86_64-linux-gnu/bits/termios-tcflow.h
/usr/include/x86_64-linux-gnu/bits/termios.h
/usr/include/x86_64-linux-gnu/bits/thread-shared-types.h
/usr/include/x86_64-linux-gnu/bits/time.h
/usr/include/x86_64-linux-gnu/bits/time64.h
/usr/include/x86_64-linux-gnu/bits/timerfd.h
/usr/include/x86_64-linux-gnu/bits/timesize.h
/usr/include/x86_64-linux-gnu/bits/timex.h
/usr/include/x86_64-linux-gnu/bits/types.h
/usr/include/x86_64-linux-gnu/bits/typesizes.h
/usr/include/x86_64-linux-gnu/bits/uintn-identity.h
/usr/include/x86_64-linux-gnu/bits/uio-ext.h
/usr/include/x86_64-linux-gnu/bits/uio_lim.h
/usr/include/x86_64-linux-gnu/bits/unistd.h
/usr/include/x86_64-linux-gnu/bits/unistd_ext.h
/usr/include/x86_64-linux-gnu/bits/utmp.h
/usr/include/x86_64-linux-gnu/bits/utmpx.h
/usr/include/x86_64-linux-gnu/bits/utsname.h
/usr/include/x86_64-linux-gnu/bits/waitflags.h
/usr/include/x86_64-linux-gnu/bits/waitstatus.h
/usr/include/x86_64-linux-gnu/bits/wchar-ldbl.h
/usr/include/x86_64-linux-gnu/bits/wchar.h
/usr/include/x86_64-linux-gnu/bits/wchar2.h
/usr/include/x86_64-linux-gnu/bits/wctype-wchar.h
/usr/include/x86_64-linux-gnu/bits/wordsize.h
/usr/include/x86_64-linux-gnu/bits/xopen_lim.h
/usr/include/x86_64-linux-gnu/bits/types/FILE.h
/usr/include/x86_64-linux-gnu/bits/types/__FILE.h
/usr/include/x86_64-linux-gnu/bits/types/__fpos64_t.h
/usr/include/x86_64-linux-gnu/bits/types/__fpos_t.h
/usr/include/x86_64-linux-gnu/bits/types/__locale_t.h
/usr/include/x86_64-linux-gnu/bits/types/__mbstate_t.h
/usr/include/x86_64-linux-gnu/bits/types/__sigset_t.h
/usr/include/x86_64-linux-gnu/bits/types/__sigval_t.h
/usr/include/x86_64-linux-gnu/bits/types/clock_t.h
/usr/include/x86_64-linux-gnu/bits/types/clockid_t.h
/usr/include/x86_64-linux-gnu/bits/types/cookie_io_functions_t.h
/usr/include/x86_64-linux-gnu/bits/types/error_t.h
/usr/include/x86_64-linux-gnu/bits/types/locale_t.h
/usr/include/x86_64-linux-gnu/bits/types/mbstate_t.h
/usr/include/x86_64-linux-gnu/bits/types/res_state.h
/usr/include/x86_64-linux-gnu/bits/types/sig_atomic_t.h
/usr/include/x86_64-linux-gnu/bits/types/sigevent_t.h
/usr/include/x86_64-linux-gnu/bits/types/siginfo_t.h
/usr/include/x86_64-linux-gnu/bits/types/sigset_t.h
/usr/include/x86_64-linux-gnu/bits/types/sigval_t.h
/usr/include/x86_64-linux-gnu/bits/types/stack_t.h
/usr/include/x86_64-linux-gnu/bits/types/struct_FILE.h
/usr/include/x86_64-linux-gnu/bits/types/struct_iovec.h
/usr/include/x86_64-linux-gnu/bits/types/struct_itimerspec.h
/usr/include/x86_64-linux-gnu/bits/types/struct_osockaddr.h
/usr/include/x86_64-linux-gnu/bits/types/struct_rusage.h
/usr/include/x86_64-linux-gnu/bits/types/struct_sched_param.h
/usr/include/x86_64-linux-gnu/bits/types/struct_sigstack.h
/usr/include/x86_64-linux-gnu/bits/types/struct_statx.h
/usr/include/x86_64-linux-gnu/bits/types/struct_statx_timestamp.h
/usr/include/x86_64-linux-gnu/bits/types/struct_timespec.h
/usr/include/x86_64-linux-gnu/bits/types/struct_timeval.h
/usr/include/x86_64-linux-gnu/bits/types/struct_tm.h
/usr/include/x86_64-linux-gnu/bits/types/time_t.h
/usr/include/x86_64-linux-gnu/bits/types/timer_t.h
/usr/include/x86_64-linux-gnu/bits/types/wint_t.h
/usr/include/x86_64-linux-gnu/gnu/lib-names-64.h
/usr/include/x86_64-linux-gnu/gnu/lib-names.h
/usr/include/x86_64-linux-gnu/gnu/libc-version.h
/usr/include/x86_64-linux-gnu/gnu/stubs-64.h
/usr/include/x86_64-linux-gnu/gnu/stubs.h
/usr/include/x86_64-linux-gnu/sys/acct.h
/usr/include/x86_64-linux-gnu/sys/auxv.h
/usr/include/x86_64-linux-gnu/sys/bitypes.h
/usr/include/x86_64-linux-gnu/sys/cdefs.h
/usr/include/x86_64-linux-gnu/sys/debugreg.h
/usr/include/x86_64-linux-gnu/sys/dir.h
/usr/include/x86_64-linux-gnu/sys/elf.h
/usr/include/x86_64-linux-gnu/sys/epoll.h
/usr/include/x86_64-linux-gnu/sys/errno.h
/usr/include/x86_64-linux-gnu/sys/eventfd.h
/usr/include/x86_64-linux-gnu/sys/fanotify.h
/usr/include/x86_64-linux-gnu/sys/fcntl.h
/usr/include/x86_64-linux-gnu/sys/file.h
/usr/include/x86_64-linux-gnu/sys/fsuid.h
/usr/include/x86_64-linux-gnu/sys/gmon.h
/usr/include/x86_64-linux-gnu/sys/gmon_out.h
/usr/include/x86_64-linux-gnu/sys/inotify.h
/usr/include/x86_64-linux-gnu/sys/io.h
/usr/include/x86_64-linux-gnu/sys/ioctl.h
/usr/include/x86_64-linux-gnu/sys/ipc.h
/usr/include/x86_64-linux-gnu/sys/kd.h
/usr/include/x86_64-linux-gnu/sys/klog.h
/usr/include/x86_64-linux-gnu/sys/mman.h
/usr/include/x86_64-linux-gnu/sys/mount.h
/usr/include/x86_64-linux-gnu/sys/msg.h
/usr/include/x86_64-linux-gnu/sys/mtio.h
/usr/include/x86_64-linux-gnu/sys/param.h
/usr/include/x86_64-linux-gnu/sys/pci.h
/usr/include/x86_64-linux-gnu/sys/perm.h
/usr/include/x86_64-linux-gnu/sys/personality.h
/usr/include/x86_64-linux-gnu/sys/poll.h
/usr/include/x86_64-linux-gnu/sys/prctl.h
/usr/include/x86_64-linux-gnu/sys/procfs.h
/usr/include/x86_64-linux-gnu/sys/profil.h
/usr/include/x86_64-linux-gnu/sys/ptrace.h
/usr/include/x86_64-linux-gnu/sys/queue.h
/usr/include/x86_64-linux-gnu/sys/quota.h
/usr/include/x86_64-linux-gnu/sys/random.h
/usr/include/x86_64-linux-gnu/sys/raw.h
/usr/include/x86_64-linux-gnu/sys/reboot.h
/usr/include/x86_64-linux-gnu/sys/reg.h
/usr/include/x86_64-linux-gnu/sys/resource.h
/usr/include/x86_64-linux-gnu/sys/select.h
/usr/include/x86_64-linux-gnu/sys/sem.h
/usr/include/x86_64-linux-gnu/sys/sendfile.h
/usr/include/x86_64-linux-gnu/sys/shm.h
/usr/include/x86_64-linux-gnu/sys/signal.h
/usr/include/x86_64-linux-gnu/sys/signalfd.h
/usr/include/x86_64-linux-gnu/sys/socket.h
/usr/include/x86_64-linux-gnu/sys/socketvar.h
/usr/include/x86_64-linux-gnu/sys/soundcard.h
/usr/include/x86_64-linux-gnu/sys/stat.h
/usr/include/x86_64-linux-gnu/sys/statfs.h
/usr/include/x86_64-linux-gnu/sys/statvfs.h
/usr/include/x86_64-linux-gnu/sys/swap.h
/usr/include/x86_64-linux-gnu/sys/syscall.h
/usr/include/x86_64-linux-gnu/sys/sysctl.h
/usr/include/x86_64-linux-gnu/sys/sysinfo.h
/usr/include/x86_64-linux-gnu/sys/syslog.h
/usr/include/x86_64-linux-gnu/sys/sysmacros.h
/usr/include/x86_64-linux-gnu/sys/termios.h
/usr/include/x86_64-linux-gnu/sys/time.h
/usr/include/x86_64-linux-gnu/sys/timeb.h
/usr/include/x86_64-linux-gnu/sys/timerfd.h
/usr/include/x86_64-linux-gnu/sys/times.h
/usr/include/x86_64-linux-gnu/sys/timex.h
/usr/include/x86_64-linux-gnu/sys/ttychars.h
/usr/include/x86_64-linux-gnu/sys/ttydefaults.h
/usr/include/x86_64-linux-gnu/sys/types.h
/usr/include/x86_64-linux-gnu/sys/ucontext.h
/usr/include/x86_64-linux-gnu/sys/uio.h
/usr/include/x86_64-linux-gnu/sys/un.h
/usr/include/x86_64-linux-gnu/sys/unistd.h
/usr/include/x86_64-linux-gnu/sys/user.h
/usr/include/x86_64-linux-gnu/sys/utsname.h
/usr/include/x86_64-linux-gnu/sys/vfs.h
/usr/include/x86_64-linux-gnu/sys/vlimit.h
/usr/include/x86_64-linux-gnu/sys/vm86.h
/usr/include/x86_64-linux-gnu/sys/vt.h
/usr/include/x86_64-linux-gnu/sys/vtimes.h
/usr/include/x86_64-linux-gnu/sys/wait.h
/usr/include/x86_64-linux-gnu/sys/xattr.h

user1424739

Asked: 2021-03-03 11:44:12 +0800 CST

Where is the source code of libc6-dev-i386 from?

0

I see this. Where the source of libc6-dev-i386 is from?

$ apt-file search /usr/include/sys/socket.h
libc6-dev-i386: /usr/include/sys/socket.h

https://packages.debian.org/search?keywords=libc6

https://www.gnu.org/software/libc/sources.html

Is it from git://sourceware.org/git/glibc.git?

user1424739

Asked: 2021-03-02 21:53:34 +0800 CST

Are /proc/sys/net/ipv4/icmp_echo_ignore_all and net.ipv4.icmp_echo_ignore_all equivalent?

0

According to the following test, it seems that net.ipv4.icmp_echo_ignore_all and /proc/sys/net/ipv4/icmp_echo_ignore_all are exactly the same. Are they exactly the same? If so, which way is the best to use?

$ sudo sysctl -w net.ipv4.icmp_echo_ignore_all=1
net.ipv4.icmp_echo_ignore_all = 1
$ cat /proc/sys/net/ipv4/icmp_echo_ignore_all
1
$ sudo tee /proc/sys/net/ipv4/icmp_echo_ignore_all <<< 0
0
$ sysctl net.ipv4.icmp_echo_ignore_all
net.ipv4.icmp_echo_ignore_all = 0

user1424739

Asked: 2021-02-26 07:31:28 +0800 CST

How to just gain root permission without running anything?

25

When I run a command with sudo like the following, subsequent sudo commands will not ask for a password anymore.

sudo ls

But this still runs ls. If I don't want to run any command at the beginning, but just stop subsequent sudo commands from asking a password later on. Is there a way to do so?

user1424739

Asked: 2021-02-26 07:10:56 +0800 CST

Why a file generated with sudo is not owned by root?

0

I run the following command in a terminal.

sudo tcpdump -c 2 -w /tmp/z.pcap icmp

Then run the following command in a terminal.

ping 8.8.8.8

The file generated belongs to the user tcpdump instead of root.

$ stat /tmp/z.pcap 
  File: /tmp/z.pcap
  Size: 158             Blocks: 8          IO Block: 4096   regular file
Device: 801h/2049d      Inode: 4068722     Links: 1
Access: (0644/-rw-r--r--)  Uid: (  115/ tcpdump)   Gid: (  120/ tcpdump)
Access: 2021-02-25 10:05:52.910772287 -0500
Modify: 2021-02-25 10:06:00.102859691 -0500
Change: 2021-02-25 10:06:00.102859691 -0500
 Birth: 2021-02-25 10:05:52.910772287 -0500

The command tcpdump belongs to the root. Why the file generated does not belong to the root?

$ ls -l $(which tcpdump)
-rwxr-xr-x 1 root root 1261512 2021/01/15-17:41:47 /usr/bin/tcpdump

user1424739

Asked: 2021-02-24 10:00:15 +0800 CST

How to monitor packet sent by ping?

0

I just want to capture the packets sent by ping. I know there are tcpdump, but it doesn't just capture the packets for a single program. So is there a way to just capture the packet for a single program? Thanks.

user1424739

Asked: 2021-02-07 16:56:18 +0800 CST

How to download the manpages of all ubuntu packages at one shot?

0

Is there a way to download the manpages of all ubuntu packages without installing the packages. I just want to look up the manpages in a non-ubuntu machine. So I don't want to and can not install the packages.

user1424739

Asked: 2021-02-07 10:20:20 +0800 CST

Where are the database files stored for apt-file?

2

I want to know where the database files searched by apt-file are stored.

apt-file search /usr/bin/lshw-gtk

But I don't see any files shown by strace look like apt-file database files. Why is it so?

I see it says the apt-file files are stored at /var/cache/apt/archives/ below. Is it too slow to search so many deb files? Does apt-file use some cache file to speed up the search?

$ time apt-file search /usr/bin/lshw-gtk
lshw-gtk: /usr/bin/lshw-gtk               

real    0m0.542s
user    0m0.361s
sys 0m0.358s

Where are apt-get files stored?

$ strace -e trace=open,openat apt-file search /usr/bin/lshw-gtk
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libdl.so.2", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libm.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/dev/urandom", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/usr/bin/apt-file", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/strict.pm", O_RDONLY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/warnings.pm", O_RDONLY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/constant.pm", O_RDONLY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/warnings/register.pm", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/Getopt/Long.pm", O_RDONLY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/vars.pm", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/Exporter.pm", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/overload.pm", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/overloading.pm", O_RDONLY|O_CLOEXEC) = 6
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/Exporter/Heavy.pm", O_RDONLY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/File/Basename.pm", O_RDONLY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl5/5.32/AptPkg/Config.pm", O_RDONLY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl5/5.32/AptPkg.pm", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/DynaLoader.pm", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/Config.pm", O_RDONLY|O_CLOEXEC) = 6
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl5/5.32/auto/AptPkg/AptPkg.so", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libapt-pkg.so.6.0", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libstdc++.so.6", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libgcc_s.so.1", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libresolv.so.2", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libz.so.1", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libbz2.so.1.0", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/liblzma.so.5", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/liblz4.so.1", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libzstd.so.1", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libudev.so.1", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libsystemd.so.0", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libgcrypt.so.20", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libxxhash.so.0", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/librt.so.1", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libgpg-error.so.0", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl5/5.32/AptPkg/hash.pm", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/Scalar/Util.pm", O_RDONLY|O_CLOEXEC) = 6
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/List/Util.pm", O_RDONLY|O_CLOEXEC) = 6
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/XSLoader.pm", O_RDONLY|O_CLOEXEC) = 6
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/auto/List/Util/Util.so", O_RDONLY|O_CLOEXEC) = 6
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl-base/Carp.pm", O_RDONLY|O_CLOEXEC) = 5
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl/5.32/Time/HiRes.pm", O_RDONLY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/perl/5.32/auto/Time/HiRes/HiRes.so", O_RDONLY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/gconv/gconv-modules.cache", O_RDONLY) = 4
openat(AT_FDCWD, "/etc/apt/apt.conf.d/", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 4
openat(AT_FDCWD, "/etc/apt/apt.conf.d/00CDMountPoint", O_RDONLY|O_NOCTTY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/etc/apt/apt.conf.d/00aptitude", O_RDONLY|O_NOCTTY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/etc/apt/apt.conf.d/00trustcdrom", O_RDONLY|O_NOCTTY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/etc/apt/apt.conf.d/01autoremove", O_RDONLY|O_NOCTTY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/etc/apt/apt.conf.d/01autoremove-kernels", O_RDONLY|O_NOCTTY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/etc/apt/apt.conf.d/01autoremove-postgresql", O_RDONLY|O_NOCTTY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/etc/apt/apt.conf.d/50apt-file.conf", O_RDONLY|O_NOCTTY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/etc/apt/apt.conf.d/50command-not-found", O_RDONLY|O_NOCTTY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/etc/apt/apt.conf.d/50kali", O_RDONLY|O_NOCTTY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/etc/apt/apt.conf.d/70debconf", O_RDONLY|O_NOCTTY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/etc/apt/apt.conf.d/80debtags", O_RDONLY|O_NOCTTY|O_CLOEXEC) = 4
Finding relevant cache files to search ...--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=36892, si_uid=504, si_status=0, si_utime=0, si_stime=1} ---
Searching through filenames ...--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=36895, si_uid=504, si_status=0, si_utime=0, si_stime=0} ---
lshw-gtk: /usr/bin/lshw-gtk    
+++ exited with 0 +++

user1424739

Asked: 2021-02-07 09:03:41 +0800 CST

Where are the database files queried by dpkg-query?

0

I don't see where are the database files checked by dpkg-query -S in its manpage. Could anybody let me know where it is? Thanks.

user1424739

Asked: 2021-02-06 17:14:38 +0800 CST

How to know which package installs a given command? [duplicate]

1

I see that llvm-objdump-9 instead of llvm-objdump are installed. What is the command to figure out which package installs it? How to remove the suffix -9? Thanks.

EDIT: Please reopen the post. The second question is not answered.

To get llvm-objdump in my $PATH, do I need to add /usr/lib/llvm-9/bin in my $PATH?

$ dpkg -S llvm-objdump
llvm-9: /usr/share/man/man1/llvm-objdump-9.1.gz
llvm-9: /usr/lib/llvm-9/bin/llvm-objdump
llvm-9: /usr/bin/llvm-objdump-9

user1424739

Asked: 2014-03-11 17:08:46 +0800 CST

When are network, broadcast and gateway required for configuring a network interface manually?

10

https://wiki.debian.org/NetworkConfiguration#Bridging_without_Switching

The above URL says, the following. But it is not clear to me when they are optional and when they are not. Could you provide me with some link to references that describe this? Thanks.

If you're configuring it manually then something like this will set the default gateway (network, broadcast and gateway are optional):

auto eth0
iface eth0 inet static
    address 192.0.2.7
    netmask 255.255.255.0
    gateway 192.0.2.254

user1424739

Asked: 2014-03-10 14:01:42 +0800 CST

Why 'sudo service networking restart" do not work?

4

Normally, if I run sudo service networking restart, it will take some time before it finishes.

But, on one machine, it returns immediately, and the results in ifconfig does not change even when /etc/network/interfaces is changed. Then I have to restart the machine in order to load any changes in the interfaces file.

I'm wondering how to debug this problem.

My OS is ubuntu server 13.10.

user1424739

Asked: 2014-03-10 07:42:02 +0800 CST

Why bonding does not improve network speed?

7

I have the following content in /etc/network/interfaces on one of my server (say server1). On another server (say server2). The content of /etc/network/interfaces is similar. Except that the mac addresses are changed accordingly and the ip address is changed to 192.168.2.2. Ubuntu 13.10 is installed on both servers.

But when I use iperf -s on server1 and iperf -c 192.168.2.1 to test the speed. I only get around 10Gbps speed (the speed of a single NIC). My switch is configured as a layer 2 switch. Does anybody know how to make the speed to be 20Gbps through bonding? Thanks.

auto em1
iface em1 inet manual
hwaddress ether c8:1f:66:e2:90:43
bond-master bond0

auto em2
iface em2 inet manual
hwaddress ether c8:1f:66:e2:90:45  
bond-master bond0

auto bond0
iface bond0 inet static
address 192.168.2.1
netmask 255.255.255.0
network 192.168.2.0
bond-mode 4
bond-miimon 100
bond-lacp-rate 1
bond-slaves em1 em2

The output of iperf is the following.

server2:~$ iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
[  4] local 192.168.2.2 port 5001 connected with 192.168.2.1 port 34014
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  11.0 GBytes  9.41 Gbits/sec

server1:~$ iperf -c 192.168.2.2
------------------------------------------------------------
Client connecting to 192.168.2.2, TCP port 5001
TCP window size: 22.9 KByte (default)
------------------------------------------------------------
[  4] local 192.168.2.1 port 34014 connected with 192.168.2.2 port 5001
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  11.0 GBytes  9.41 Gbits/sec

I also tried to change the mode to balance-alb and balance-rr. But they don't lead to improved performance as well. Does anybody know to debug the problem? Thanks.

auto bond0
iface bond0 inet static
address 192.168.2.1
netmask 255.255.255.0
network 192.168.2.0
#bond-mode balance-rr
bond-mode balance-alb
bond-miimon 100
bond-slaves em1 em2

user1424739

Asked: 2014-03-10 06:30:24 +0800 CST

Is it wise to run computing virtual machines on KVM?

0

I have a physical server with 384GB memory. My main applications are to run CPU and I/O intensive programs. I could run everything on the physical server.

But I'm wondering if it is better to host a virtual machine on the physical server to simplify future system restoration issues. For example, if the physical server crashes, I can still grab the image of the virtual machine and run it somewhere else. If most of my applications are installed in the virtual machine, then few applications shall be installed on the physical machine. It sounds this strategy can make the system restoration much easier. Also, when I want to duplicate the system configuration, I just need to make a copy of the image of the virtual machine.

On the other hand, running processes on a virtual machine is slower than running on a physical machine. And since I have a large memory, the swap space for the virtual machine is also large (should it be 384GB) and is not based on a physical partition. I think that this can cause performance issues.

Could any experienced users provide some recommendations on whether it is wise to run virtual machines for computing purposes? Thanks.

user1424739

Asked: 2014-01-08 18:33:05 +0800 CST

What is the difference between security, updates, proposed and backports in /etc/apt/apt.conf.d/50unattended-upgrades?

24

I see the following lines in /etc/apt/apt.conf.d/50unattended-upgrades. But I'm not able to find the man page for them. Could anybody point me the detailed document for each of them? Thanks.

Unattended-Upgrade::Allowed-Origins {
  "${distro_id}:${distro_codename}-security";
  "${distro_id}:${distro_codename}-updates";
//  "${distro_id}:${distro_codename}-proposed";
//  "${distro_id}:${distro_codename}-backports";
};

user1424739

Asked: 2014-01-03 15:57:53 +0800 CST

Does ubuntu apt eliminate the need of backporting (as described by RedHat)?

0

I see Backporting mentioned below.

https://access.redhat.com/site/security/updates/backporting/

I'm not sure what they mean by "module". For the example scenario mentioned in the link, it sounds that, in ubuntu, if users only use packages managed by apt, there is no need to backport packages in the sense that RedHat means. Is it so? Thanks.

Does ubuntu have elfdump?

Where is the manpage of endsgent?

the raw command to compile `login`

About files in /usr/include/x86_64-linux-gnu

Where is the source code of libc6-dev-i386 from?

Are /proc/sys/net/ipv4/icmp_echo_ignore_all and net.ipv4.icmp_echo_ignore_all equivalent?

How to just gain root permission without running anything?

Why a file generated with sudo is not owned by root?

How to monitor packet sent by ping?

How to download the manpages of all ubuntu packages at one shot?

Where are the database files stored for apt-file?

Where are the database files queried by dpkg-query?

How to know which package installs a given command? [duplicate]

When are network, broadcast and gateway required for configuring a network interface manually?

Why 'sudo service networking restart" do not work?

Why bonding does not improve network speed?

Is it wise to run computing virtual machines on KVM?

What is the difference between security, updates, proposed and backports in /etc/apt/apt.conf.d/50unattended-upgrades?

Does ubuntu apt eliminate the need of backporting (as described by RedHat)?

How to install Google Chrome

Is there a command to list all users? Also to add, delete, modify users, in the terminal?

How to delete a non-empty directory in Terminal?

How to unzip a zip file from the Terminal?

How can I copy the contents of a folder to another folder in a different directory using terminal?

How do I install a .deb file via the command line?

How do I run .sh scripts?

How do I install a .tar.gz (or .tar.bz2) file?

How to list all installed packages

Unable to lock the administration directory (/var/lib/dpkg/) is another process using it?