Searching shared libraries in Linux - linux

please explain me why on x86_64 Scientific Linux no file under /etc/ld.so.conf.d contains the directory /usr/lib64?
The list of directories to be searched by program loader is stored in the file /etc/ld.so.conf. On my distributive, this file stores this row: include ld.so.conf.d/.conf*
And the above directory consists of:
[root#dev_host build]$ ls -la /etc/ld.so.conf.d
total 36
drwxr-xr-x. 2 root root 4096 Aug 29 23:13 .
drwxr-xr-x. 103 root root 12288 Sep 18 03:41 ..
-rw-r--r--. 1 root root 17 Mar 20 2012 atlas-x86_64.conf
-r--r--r--. 1 root root 324 May 7 23:40 kernel-2.6.32-431.17.1.el6.x86_64.conf
-r--r--r--. 1 root root 324 Nov 22 2013 kernel-2.6.32-431.el6.x86_64.conf
-rw-r--r--. 1 root root 17 Feb 12 2014 mysql-x86_64.conf
lrwxrwxrwx 1 root root 31 Aug 11 14:46 postgresql-pgdg-libs.conf -> /etc/alternatives/pgsql-ld-conf
-rw-r--r--. 1 root root 22 Sep 7 2011 qt-x86_64.conf
I examined all these files - there is no /usr/lib64. Why? Is it stored in /etc/ld.so.cache?

Related

Why some binaries are duplicated in the Linux filesystem?

Good Morning,
There are some commands that are both in /bin and in /usr/bin in our Yocto filesystem.
Is that normal? I don't think it's a mistake we made in building our Yocto filesystem because I see the same thing in my regular Debian Buster distribution (see below). But what is the purpose of that duplication?
Here is an example of what I'm talking about:
root#debian:~# ls -l /bin/zip* /usr/bin/zip*
-rwxr-xr-x 1 root root 213136 Aug 16 2015 /bin/zip
-rwxr-xr-x 1 root root 90432 Aug 16 2015 /bin/zipcloak
-rwxr-xr-x 1 root root 48497 Jul 21 2020 /bin/zipdetails
-rwxr-xr-x 1 root root 2953 Jan 10 16:12 /bin/zipgrep
-rwxr-xr-x 2 root root 183136 Jan 10 16:12 /bin/zipinfo
-rwxr-xr-x 1 root root 86048 Aug 16 2015 /bin/zipnote
-rwxr-xr-x 1 root root 86048 Aug 16 2015 /bin/zipsplit
-rwxr-xr-x 1 root root 213136 Aug 16 2015 /usr/bin/zip
-rwxr-xr-x 1 root root 90432 Aug 16 2015 /usr/bin/zipcloak
-rwxr-xr-x 1 root root 48497 Jul 21 2020 /usr/bin/zipdetails
-rwxr-xr-x 1 root root 2953 Jan 10 16:12 /usr/bin/zipgrep
-rwxr-xr-x 2 root root 183136 Jan 10 16:12 /usr/bin/zipinfo
-rwxr-xr-x 1 root root 86048 Aug 16 2015 /usr/bin/zipnote
-rwxr-xr-x 1 root root 86048 Aug 16 2015 /usr/bin/zipsplit
Thanks for your reading.
some of those binary does some special functions and purpose other than the main program.
just take a look at the grep program
original 'grep'
extended ones are - egrep, bgrep, pgrep, fgrep.
they all do the same thing but gives the user more flexibility and ease of usage

Jenkinsfile ,by using sh, says No such file or directory, but it exists

I'm studying jenkins, trying to package a maven project to a war, then move it to a previously started tomcat webapps directory(/opt/tomcat/latest/webpass), but it reports 'No such file or directory'.
Already find out what causes this, but don't know why. Jenkins don't use the same filesystem as original?
Here is my troubleshooting:
1、I create a directory in my linux server under / as temp20190808.
2、then in jenkins file add sh 'ls / -l', there is no temp20190808,also the description of each file in ls form show differenly compare with original(there are details under).
3、using jenkins file, i create a file under / as jenkinstmp2019, then ls / -l, it's there, but after rm the code of creating jenkinstmp2019, then rebuild, ls / -l, jenkinstmp2019 no longer there, so the jenkins file system is a onetime job?
Here are code elaboration on point 1,2:
in my linux server, using ls / -l, there is a tmp20190808 i just created.
total 24
lrwxrwxrwx. 1 root root 7 Jun 19 16:53 bin -> usr/bin
dr-xr-xr-x. 5 root root 4096 Aug 1 04:55 boot
drwxr-xr-x. 17 root root 2860 Aug 7 02:48 dev
drwxr-xr-x. 86 root root 8192 Aug 7 20:52 etc
drwxr-xr-x. 4 root root 46 Jul 12 08:12 home
lrwxrwxrwx. 1 root root 7 Jun 19 16:53 lib -> usr/lib
lrwxrwxrwx. 1 root root 9 Jun 19 16:53 lib64 -> usr/lib64
drwxr-xr-x. 2 root root 6 Apr 11 2018 media
drwxr-xr-x. 2 root root 6 Apr 11 2018 mnt
drwxr-xr-x. 5 root root 53 Jul 23 08:11 opt
dr-xr-xr-x. 101 root root 0 Aug 7 02:47 proc
dr-xr-x---. 7 root root 215 Aug 6 02:53 root
drwxr-xr-x. 28 root root 920 Aug 8 02:03 run
lrwxrwxrwx. 1 root root 8 Jun 19 16:53 sbin -> usr/sbin
drwxr-xr-x. 2 root root 6 Apr 11 2018 srv
dr-xr-xr-x. 13 root root 0 Aug 7 02:47 sys
drwxr-xr-x. 2 root root 6 Aug 8 01:50 temp1
drwxrwxrwt. 20 root root 4096 Aug 8 02:23 tmp
drwxr-xr-x. 2 root root 22 Aug 8 01:39 tmp20190808
drwxr-xr-x. 13 root root 155 Jun 19 16:53 usr
drwxr-xr-x. 20 root root 4096 Jul 12 07:36 var
in jenkins.
total 8448
drwxr-xr-x. 1 root root 19 Jun 9 2016 bin
drwxr-xr-x. 2 root root 6 May 30 2016 boot
-rw-------. 1 root root 8646656 Jun 9 2016 core
drwxr-xr-x. 5 root root 360 Aug 8 01:58 dev
drwxr-xr-x. 1 root root 66 Aug 8 01:58 etc
drwxr-xr-x. 2 root root 6 May 30 2016 home
drwxr-xr-x. 1 root root 45 Jun 9 2016 lib
drwxr-xr-x. 2 root root 34 Jun 8 2016 lib64
drwxr-xr-x. 2 root root 6 Jun 8 2016 media
drwxr-xr-x. 2 root root 6 Jun 8 2016 mnt
drwxr-xr-x. 2 root root 6 Jun 8 2016 opt
dr-xr-xr-x. 123 root root 0 Aug 8 01:58 proc
drwx------. 1 root root 33 Aug 8 01:58 root
drwxr-xr-x. 3 root root 30 Jun 8 2016 run
drwxr-xr-x. 2 root root 4096 Jun 8 2016 sbin
drwxr-xr-x. 2 root root 6 Jun 8 2016 srv
dr-xr-xr-x. 13 root root 0 Aug 7 02:47 sys
drwxrwxrwt. 1 root root 29 Jun 9 2016 tmp
drwxr-xr-x. 1 root root 30 Jun 10 2016 usr
drwxr-xr-x. 1 root root 41 Jun 9 2016 var
As you can see, it's like two totally different linux server, but it's the same one.
So i'm wondering whether jenkins create a temp virtual file server to execute it's job, so can't access to original file except it's own directory.
Find out the reason by myself.
The real cause is agent, i before used agent { docker { image 'XXX' } }, which makes jenkins run its job on docker image.Then i change it to agent any, so job will run on the server jenkins is deployed on.

`cd` to a folder in bash script not working: No such folder [duplicate]

This question already has answers here:
Why can't I change directories using "cd" in a script?
(33 answers)
'\r': command not found [duplicate]
(3 answers)
Closed 4 years ago.
This is my entire script. it is simply to avoid having to type it again and again
cd api
rails s -p 3001 -b 0.0.0.0
cd ..
When I am in the directory of the script and run cd api it works just fine. However when I run the script via ./start_server It does not work. Here is the output of ls -al:
mendel#DESKTOP-LIKG5E5:/mnt/c/Projects/chaverim-update$ ls -al
total 8
drwxrwxrwx 0 root root 512 Apr 13 12:32 .
drwxrwxrwx 0 root root 512 Apr 5 12:40 ..
drwxrwxrwx 0 root root 512 Apr 13 12:09 api
-rwxrwxrwx 1 root root 1237 Apr 5 12:40 boxfile.yml
drwxrwxrwx 0 root root 512 Apr 8 16:54 .bundle
drwxrwxrwx 0 root root 512 Apr 8 16:54 client
drwxrwxrwx 0 root root 512 Apr 13 12:09 .git
-rwxrwxrwx 1 root root 11 Apr 5 12:40 .gitignore
-rwxrwxrwx 1 root root 1097 Apr 5 12:40 LICENSE
drwxrwxrwx 0 root root 512 Apr 5 12:40 nginx
-rwxrwxrwx 1 root root 82 Apr 5 12:40 Procfile
-rwxrwxrwx 1 root root 67 Apr 5 12:40 README.md
-rwxrwxrwx 1 root root 188 Apr 5 12:40 run_tests
-rwxrwxrwx 1 root root 28 Apr 5 12:40 start_client
-rwxrwxrwx 1 root root 41 Apr 13 12:52 start_server
drwxrwxrwx 0 root root 512 Apr 8 16:54 vendor
As you can see there is a folder called api at the top and the start_server script is set to have execution permissions.

Installation Of Cassandra

I have download cassandra via terminal but problem is where are the other folders like data, conf, lib, doc etc.
i can see only some files as shown in figure i.e Click here
where is the other folders ?
By "download cassandra via terminal" and your screenshot, I'll assume that you installed Cassandra via apt-get.
From the Apache Cassandra project Wiki, section on Installation from Debian packages:
The default location of configuration files is /etc/cassandra.
The default location of log and data directories is /var/log/cassandra/ and /var/lib/cassandra.
As for the lib directory, check how your $CASSANDRA_HOME is being set:
$ grep CASSANDRA_HOME /etc/init.d/cassandra
CASSANDRA_HOME=/usr/share/cassandra
$ ls -al /usr/share/cassandra/
total 8312
drwxr-xr-x 3 root root 4096 Dec 13 07:57 .
drwxr-xr-x 372 root root 12288 Nov 28 08:51 ..
-rw-r--r-- 1 root root 5962385 Jun 1 2016 apache-cassandra-3.6.jar
lrwxrwxrwx 1 root root 24 Jun 1 2016 apache-cassandra.jar -> apache-cassandra-3.6.jar
-rw-r--r-- 1 root root 1902216 Jun 1 2016 apache-cassandra-thrift-3.6.jar
-rw-r--r-- 1 root root 875 May 31 2016 cassandra.in.sh
drwxr-xr-x 3 root root 12288 Dec 13 07:57 lib
-rw-r----- 1 root root 82123 Oct 20 2015 metrics-core-2.2.0.jar
-rw-r----- 1 root root 9639 Oct 20 2015 metrics-graphite-2.2.0.jar
-rw-r--r-- 1 root root 509144 Jun 1 2016 stress.jar
Note that Cassandra's lib directory is shown in the middle of the directory listing above.

CHROOT : Allowing outside access to chrooted users with mount bind

I have a chrooted user(username: clientdev) which I have jailed inside their home directory. This chroot directory is /home/clientdev/ which is owned by root.
Now I need this clientdev user to be able access the tomcat web application folder which is residing under /mnt/datadrive/tomcat/webapps.
What I have done is :
chroot the user with a public key of their own to the home
directory.
Create a folder under /home/clientdev called tomcat_ROOT and gave
the ownership to clientdev.
Now when I run the command :
mount -bind /mnn/datadrive/tomcat/webapps /home/clientdev/tomcat_ROOT
The folder disappears from the directory listing inside /home/clientdev if I login with clientdev. My root user can see it but now the desired user.
Any help would be greatly appreciated
Thanks in advance,
Peter
Output of ls -l /home/clientdev/tomcat_ROOT:
drwxr-xr-x. 6 root root 4096 Apr 11 15:07 .
drwxrwxr-x. 12 root root 4096 Apr 11 15:07 ..
drwxr-xr-x. 3 root root 4096 Apr 9 22:10 webapp1
drwxr-xr-x. 4 root root 4096 Mar 18 18:43 webapp2
drwxr-xr-x. 3 root root 4096 Apr 9 22:11 webapp3
drwxrwxr-x. 10 root root 4096 Apr 11 15:20 ROOT
Output of ls -l /home/clientdev/:
drwx------. 4 clientdev clientdev 4096 Apr 10 21:36 .
drwxr-xr-x. 7 root root 4096 Apr 10 22:07 ..
-rw-------. 1 clientdev clientdev 664 Apr 10 21:43 .bash_history
-rw-r--r--. 1 clientdev clientdev 18 Apr 23 2012 .bash_logout
-rw-r--r--. 1 clientdev clientdev 176 Apr 23 2012 .bash_profile
-rw-r--r--. 1 clientdev clientdev 124 Apr 23 2012 .bashrc
drwx------. 2 clientdev clientdev 4096 Apr 10 19:20 .ssh
drwxr-xr-x. 2 clientdev clientdev 4096 Apr 10 21:34 tomcat_ROOT

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