getcap is a command-line utility that is used to display the capabilities of files on a Linux system. Capabilities are a security feature in Linux that allow fine-grained control over the privilege level of individual processes.
The capabilities are divided into three groups:
- Effective capabilities: The capabilities that are currently in effect for a process.
- Permitted capabilities: The capabilities that a process is allowed to use.
- Inheritable capabilities: The capabilities that a process can pass on to its child processes.
The getcap command is used to display the capabilities of files on a Linux system by checking the file’s capability bit-mask, which is a representation of the file’s capabilities. The capability bit-mask is stored in the file’s extended attributes, which can be viewed using the getcap command.
The getcap command takes the file names as arguments, and it displays the name of the file and its corresponding capabilities.
For example, if you want to see the capabilities of a file called ‘myfile’, you can use the command:
# getcap myfile
This will display the name of the file ‘myfile’ and its corresponding capabilities. The output of the command will be in the format of:
filename = capability1,capability2,capability3
It’s important to note that the getcap command can only display the capabilities of files that have been set with the setcap command, which is a tool used to set the capabilities of files.
If you encounter the below error while running the command getcap:
getcap: command not found
you may try installing the below package as per your choice of distribution:
| Distribution | Command |
|---|---|
| Debian | apt-get install libcap2-bin |
| Ubuntu | apt-get install libcap2-bin |
| Alpine | apk add libcap |
| Arch Linux | pacman -S libcap |
| Kali Linux | apt-get install libcap2-bin |
| CentOS | yum install libcap |
| Fedora | dnf install libcap |
| Raspbian | apt-get install libcap2-bin |
getcap Command Examples
1. Get capabilities for the given files:
# getcap /path/to/file1 path/to/file2 ...
2. Get capabilities for all the files recursively under the given directories:
# getcap -r /path/to/directory1 path/to/directory2 ...
3. Displays all searched entries even if no capabilities are set:
# getcap -v /path/to/file1 path/to/file2 ...
Summary
In summary, getcap is a command-line utility that is used to display the capabilities of files on a Linux system. Capabilities are a security feature in Linux that allow fine-grained control over the privilege level of individual processes. The getcap command is used to display the capabilities of files by checking the file’s capability bit-mask, which is stored in the file’s extended attributes. The output of the command will be in the format of filename = capability1,capability2,capability3 and it can only display the capabilities of files that have been set with the setcap command.