Links on Android: what they are, where they are and why you need them in the system

If you have ever come across the term links on Androidbut could not understand what it is and how it affects the operation of your smartphone, this article will help you figure it out. In an operating system, the word "links" can refer to several concepts, from symbolic links in the file system to shortcuts in the interface or even network connections. But most often, users come across this term in the context Android The word "links" can refer to several concepts, from symbolic links in a file system to shortcuts in an interface or even network connections. But most often users encounter this term in the context file linksthat the system creates to optimize the operation of applications and save memory.

At first glance, the topic may seem too technical, but in practice an understanding of how they work links, helps solve a number of problems: from freeing up space on the device to eliminating errors when installing applications. For example, you may have noticed that some files are taking up less disk space than expected, or that the app's size hasn't increased since you updated it. This may just be due to the link mechanism. In this article we will look at what they are links on Android, where they are stored, how to check them and whether they can be deleted without harm to the system.

What are links in the context of Android: main types

B Android term "links" usually means one of three main types of links:

• 🔗 Symlinks (symlinks) - these are virtual files that point to other files or folders. They do not contain data themselves, but only store the path to the original file. For example, many system libraries in /system/lib are actually symlinks, leading to current versions in other folders.
• 📎 Hard links are a less common type that creates an additional name for the same file at the physical level. Unlike symlinks, hard links do not break if the original file is moved or renamed.
• 🌐 Network or short links are no longer a file system, but, for example, shortened URLs in a browser or application (as in Google Chrome or Firefox), or links to cloud resources (for example, in Google Drive).

The most important for users Android are symbolic links, since they are actively used by the system for:

• 📱 Space saving (one file can be accessed from several places without duplication).
• 🔄 Backward compatibility (old applications can access files using old paths, even if they are physically moved).
• 🛠️ Simplifying updates (for example, when changing version Android the system can simply update the link, rather than rewrite all the files).

Real life example: if you have ever looked into the folder /system/bin via Root Explorer or ADB, you might have noticed that many executable files there are - these are symlinks leading to /system/xbin or other directories. This allows Android to flexibly manage system utilities without unnecessary duplication.

Where links are stored on Android and how to find them

Symbolic and hard links in Android are stored directly in the file system, but you can only see them if you have root access or through ADB (Android Debug Bridge) Here are the main places where they are found:

To find symlinks on your device yourself:

1. Connect to your smartphone via ADB (instructions are in official documentation Android).
2. Run the command:

   adb shell
   ls -l /system/bin

   In the output, symlinks will be marked with an arrow, for example:

   lrwxrwxrwx 1 root root 11 2023-01-01 12:00 sh -> /system/bin/mksh
3. To check hard links, use:

   adb shell
   stat /path/to/file

   Pay attention to the field Links —if the value is greater than 1, then the file has hard links.

Without root you will not be able to view system symlinks, but you may be able to see links in user folders (for example in /sdcard), if they are there. However, most of the links in Android are hidden from the average user, since they are critical for the operation of the system.

Why Android uses links: advantages and risks

The use of links in Android is not just a technical feature, but an important optimization mechanism. Here are the key reasons why the system actively uses them:

• 💾 Memory saving: instead of duplicating the same files (for example, libraries) in different places, the system creates links. This is especially true for devices with limited storage.
• 🔄 Simplifying updates: when updating Android or applications, just update the original file, and all links will automatically point to the new version.
• 🛡️ Security: some symlinks are used to isolate applications (for example, in /data/data) to limit access to critical files.
• ⚡ Performance: access to a file via a link occurs almost instantly, since it does not require physical reading of duplicated data.

However, this mechanism also has a downside:

• ⚠️ "Broken" links: If the original file is deleted or moved, the symlink becomes broken ("broken"), which can cause errors in applications.
• 🔍 Difficulty of debugging: When searching for problems (for example, why an application does not start), it can be difficult to track which file is being used through a link.
• 🔒 Restrictions for users: without root access it is impossible to change or remove system symlinks, even if they interfere.

Important: some manufacturers (for example, Samsung or Xiaomi) actively use symlinks to implement proprietary functions, such as "Dual applications" or "Game Booster". Removing such links can lead to the inoperability of these features.

Is it possible to delete links on Android and when is it dangerous?

Question about deletion links to Android is one of the most controversial. The answer depends on type of link and its location:

⚠️ Attention: Removing system symlinks (for example, in /system) without understanding the consequences can lead to device inoperability ("brick"). You can often restore your smartphone after this only by flashing it.

Let's take a look at which links can be touched and which cannot:

• ✅ Custom symlinks (for example, in /sdcard): if you created them yourself (for example, for ease of access to files), they can be deleted without risk.
• ⚠️ Links in /data/data: application data is stored here Deleting links may break the operation of a specific application, but not the entire system.
• ❌ System symlinks (in /system, /vendor): deleting them almost always leads to critical errors. The exception is if you know exactly what you are doing (for example, when customizing the firmware).

If you are all If you want to delete symlink, do it via ADB:

adb shell
rm /path/to/symlink

For hard links, the process is more complicated - they cannot be deleted separately from the original file. When you delete a file, all its hard links become broken.

Make sure it's not a system link|Back up your important data|Check if the file is in use by the apps you want|Use the command ls -l to confirm the file type-->

How links affect device performance and memory

One of the main questions users: is it possible to free up space on android by deleting or changing links? The answer is ambiguous. On the one hand, symlinks themselves take up minimal space (usually a few bytes), since they only store the path to the file. On the other hand, they can indirectly affect memory: Is it possible to free up space on Android by deleting or changing links: thanks to symlinks, many files (for example, libraries) are not duplicated, which can save money on the system partition.

• 📉 Saving space: thanks to symlinks, many files (for example, libraries .so) are not duplicated, which can save hundreds of megabytes on the system partition.
• 🐢 Slowdown with broken links: if the symlink leads to nowhere, the system wastes time trying to access, which can slow down the launch of applications.
• 🔄 Caching: some links are used for optimization cache (for example, in /data/dalvik-cache), and deleting them may cause applications to be recompiled the next time you launch them.

To assess the impact of links on your device:

1. Check the free space in /system and /data via ADB:

   adb shell df -h

2. Find broken links (if there is a root):

   adb shell
   find /system -type l -xtype l

   (the command looks for symlinks leading to non-existent files).

3. Analyze the output: if there are a lot of broken links, this may be the reason lags.

In practice Removing symlinks rarely gives a significant increase in memory, but it can help in specific cases - for example, if the application constantly crashes due to a broken link to the library. In most cases, it is better to focus on clearing the cache or deleting unnecessary applications.

Problems with links: how to diagnose and fix errors

If your Androidsmartphone starts behaving strangely - applications crash, the system slows down, or errors like "File not found"appear - problems with links may be to blame. Here are typical symptoms and ways to eliminate them:

For diagnostics:

1. Check the system logs for errors related to files:

   adb logcat | grep -i "link\|file not found"

2. Use File Manager with root accessto manually check suspicious folders (for example, /data/app-lib).
3. If the problem is in the system link, the easiest way is reset the device to factory settings or reflash it.

⚠️ Attention: Some custom firmware (for example, LineageOS) may use non-standard symlinks. If you encounter problems after flashing the firmware, check the documentation for your version. Android.

adb shell
ln -s /path/to/original/file /path/to/symlink

Practical examples of working with links on Android

Let's look at several real-life scenarios where knowledge about symlinks can be useful:

• 📲 Transferring applications to an SD card: some applications (for example, App2SD) create symlinks to “trick” the system into thinking that files are in internal memory. This saves space, but can slow down the work if the card is slow.
• 🔧 Modifying system files: when rooting a device, you often have to replace system files (for example, build.propIn order not to break the original, you can create a symlink to a modified version.
• 🎮 Game mods: some cheats or mods for games (for example, in GTA San Andreas) are installed via symlinks, leading to modified files in /sdcard.

Example command for creating a symlink (requires root):

adb shell
su
ln -s /sdcard/modded_file.apk /data/app/com.example.game-1/base.apk

FAQ: Frequently asked questions about links on Android