Lrwxrwxrwx 1 ec2-user ec2-user 30 Apr 25 21:10 AU -> /opt/apps/maps/world/australia Notice that the link in this case is using an absolute pathname where the one shown earlier was relative (in the current directory). This one points to a file in an altogether different directory. Looking at the symlink listed above, note that we have to use a special command - readlink - to see its contents as the OS will assume we want to see the contents of the file that it refers to - not the link itself. And, to be honest, a symbolic link could actually be set up to point to itself, though there would be little value in such a link. If you were to look at the contents of a symbolic link, you would see very clearly that all it contains is the file system path (absolute or relative) to some other file on the system - usually in another directory, though this won't always be the case. How soft (symbolic) links work is easy to determine. lrwxrwxrwx 1 lguy lguy 5 maybe-not -> maybe The first character in a long listing gives this away quite easily. If you look at a symbolic link using the ls command, you can easily tell that it's a symbolic link.
A soft or "symbolic" link is simply a file that points to another file. It's not an issue of malleability, but a very big difference in how each type of link is implemented in the file system. Hard vs soft linksĭon't let the names fool you.
Let's look at how links can be most useful, how you can find and identify them, and what you need to consider when setting them up. This is because the chmod command will apply the permission change to the target directory /etc.Īpparently, as a regular user “ kent”, we’re not permitted to change the permission of /etc.Symbolic and hard links provide a way to avoid duplicating data on Unix/Linux systems, but the uses and restrictions vary depending on which kind of link you choose to use. We cannot change the permission of the soft link /tmp/test3/etc. Finally, let’s attempt to change the permissions of the two soft links to 700: kent$ chmod 700 /tmp/test3/etcĬhmod: changing permissions of '/tmp/test3/etc': Operation not permitted Lrwxrwxrwx 1 kent kent 4 Mar 26 23:27 /tmp/test3/etc -> /etc/ Lrwxrwxrwx 1 kent kent 29 Mar 26 23:27 /tmp/test3/aDirectory -> /home/kent/Desktop/aDirectory/ Next, we’re going to create two links to the directories above under the directory /tmp/test3: kent$ ln -s /etc /home/kent/Desktop/aDirectory /tmp/test3 No matter whether the change is successful or not, the permission of the soft link is still 0777.įirst, let’s find two directories we want to link: kent$ ls -ld /etc /home/kent/Desktop/aDirectoryĭrwxr-xr-x 131 root root 12288 Mar 26 11:07 /etcĭrwxr-xr-x 2 kent kent 4096 Mar 26 23:23 /home/kent/Desktop/aDirectory Moreover, if we change the soft link’s permission, the chmod command will forward the change to the target file or directory. Size: 18 Blocks: 0 IO Block: 4096 symbolic linkĪs the stat output above shows, the two links are created under the directory /tmp/test and pointing to desired target directories.Īlternatively, we can create links to multiple directories in another form:
Let’s say we want to create two soft links under /tmp/test pointing to the Java JDK directory /usr/lib/jvm/java-15-jdk and Python directory /usr/lib/python3.9: $ ln -s -t /tmp/test /usr/lib/jvm/java-15-jdk /usr/lib/python3.9 Īs usual, let’s understand how the command works through an example. Now, let’s take a look at the syntax to do that: ln -s -t DIR_TO_CREATE_LINKS TARGET_DIR1 TARGET_DIR2.
0 kommentar(er)
