The "Linux" kernel handles the scheduling/multitasking and all the I/O, and it knows what an UIDs/owner is.
But it does not know what a shell is, and does not know that a UID is stored in a passwd file.
Nevertheless the kernel handle many atomic operations. Its API towards userland is in man page section 2; in Linux you can list them with:
Code:
man -k . | grep '(2)'
The userland is all the processes. The shell is a normal process. A lot userland code is stored in shared libraries, so the processes simply load the libraries and stay small. The ps -ef command also lists some kernel threads and assignes the PID 0, while the real processes in userland have PID 1 and higher.
The criteria interactive/non-interactive and login/non-login is a matter of the shell, or of the process that invokes it. You can read more of it in the man page
Code:
man sh
man bash
The invocation of a new process is done via a couple of the kernel API functions, basically fork() and exec().
Hello fellow *nix users!
I am a bit confused how could I get an environment of a "fresh/clean" login shell, that is, the environment at that moment when user has started e.g. a new terminal/console or so.
So this is the sequence of actions I should be able to do in a single shell session:
... (6 Replies)
Can anybody help me to write a shell script to login interactive system
once u open a connection using telnet it will ask for
USERCODE:
PASSWORD:
DOMAIN: (1 Reply)
Q. Write a script that behaves both in interactive and non interactive mode. When no arguments are supplied it picks up each C program from the directory and prints first 10 lines.
It then prompts for deletion of the file.
If user supplies arguments with the script , then it works on those files... (1 Reply)
I would like to practice shell scripting and need an environment - free shell account. I tried Arbornet and the freeshell.org. But both always give me error: "File operations disabled, server identity can't be verified". Any idea what I should do? thanks in advance. (9 Replies)
Hi Guys,
Excuse if am asking silly Que ... :rolleyes:
Please explain me whats difference between login and interactive shell in Linux .. Have googled but still in doubt .. :confused:
--Shirish Shukla (4 Replies)
Hi i need a c programm to login in unix(solaris).
non-interactivley because it seems difficult to do it with unix shell scripting and passwd command cant be used and also
i don't have expect installed and i am not allowed to installed expect in our servers.
is there any c programm that can help... (1 Reply)
Hello experts,
Is it possible to have an user account on RHEL 6.3 as a su-only account, but with ssh capability and no interactive login? Let me elaborate.
Say, we have a cluster of 5 RHEL 6.3 servers and an user account (strmadmin) on each of the server as an su-only... (1 Reply)
Hello all,
for security reasons my compagny imposes that my script be launch remotly via ssh under the users login shell.
So serverA launches the ssh command to serverB which has a local user with my script as a login shell.
Local script works like a charm on his own.
serverB$ grep... (20 Replies)
Hey folks,
When a user is added to a new group, the user has to be log out and log in again to make the new group effective. Is there any system command or technique to refresh user group ID update without re-login?
I am not talking about to use "login" or "su -l" commands which can only make... (2 Replies)
I am sorry for creating a new topic after my previous inquiry was closed, but I tried and tried and I do not know how to edit my previous post. This is not exactly any homework, this is one of 40 questions we were expected to prepare for one of the labs. I searched and read what I could and still... (4 Replies)
Discussion started by: me_me_me
4 Replies
LEARN ABOUT BSD
pldd
PLDD(1) Linux User Manual PLDD(1)NAME
pldd - display dynamic shared objects linked into a process
SYNOPSIS
pldd pid
pldd option
DESCRIPTION
The pldd command displays a list of the dynamic shared objects that are linked into the process with the specified process ID. The list
includes the libraries that have been dynamically loaded using dlopen(3).
OPTIONS
-?, --help
Display program help message.
--usage
Display a short usage message.
-V, --version
Display the program version.
EXIT STATUS
On success, pldd exits with the status 0. If the specified process does not exist, the user does not have permission to access its dynamic
shared object list, or no command-line arguments are supplied, pldd exists with a status of 1. If given an invalid option, it exits with
the status 64.
VERSIONS
pldd is available since glibc 2.15.
CONFORMING TO
The pldd command is not specified by POSIX.1. Some other systems have a similar command.
NOTES
The command
lsof -p PID
also shows output that includes the dynamic shared objects that are linked into a process.
The gdb(1) info shared command also shows the shared libraries being used by a process, so that one can obtain similar output to pldd using
a command such as the following (to monitor the process with the specified pid):
$ gdb -ex "set confirm off" -ex "set height 0" -ex "info shared"
-ex "quit" -p $pid | grep '^0x.*0x'
BUGS
Since glibc 2.19, pldd is broken: it just hangs when executed. It is unclear if it will ever be fixed.
EXAMPLE
$ echo $$ # Display PID of shell
1143
$ pldd $$ # Display DSOs linked into the shell
1143: /usr/bin/bash
linux-vdso.so.1
/lib64/libtinfo.so.5
/lib64/libdl.so.2
/lib64/libc.so.6
/lib64/ld-linux-x86-64.so.2
/lib64/libnss_files.so.2
SEE ALSO ldd(1), lsof(1), dlopen(3), ld.so(8)COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the
latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
GNU 2017-09-15 PLDD(1)