{{indexmenu_n>7}}
====== VEOS User Guide ======

**VEOS** is a Linux-based operating system designed for managing telecom equipment and services.\\  
This guide contains basic instructions for working with the system, information about common commands, and usage techniques.

**Key user features:**
  * Multi-user operation with permission separation
  * Execution of standard Linux commands and utilities
  * Access to the built-in help system (''%%man%%'', ''%%info%%'')
  * File and process management from the command line
  * Installation of additional software using the package manager (''%%dnf%%'')

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===== 1. System boot and login =====

=== 1.1. Booting VEOS ===

VEOS starts automatically after the computer is powered on. The **GRUB** bootloader menu appears on the screen, listing the available boot options.

^ Action ^ Key ^
| Select a boot option | ''%%Up%%'' / ''%%Down%%'' arrow keys |
| Immediately boot the selected option | ''%%Enter%%'' |
| Edit boot parameters | ''%%E%%'' |
| Switch to graphical boot display mode | ''%%Esc%%'' |

During the boot process, messages about starting various services are displayed on the screen. Each line begins with the status **[Message]** and either ''%%OK%%'' or ''%%FAILED%%''.

<note warning>
If any boot stage finishes with the ''%%FAILED%%'' status, administrator intervention may be required.
</note>

Main boot stages:
  * Kernel loading
  * Mounting file systems
  * Starting system services
  * (If required) checking file systems for errors

=== 1.2. Logging into the system ===

After boot is completed, the system switches to console mode and displays a login and password prompt.

<code>
Login: _ 
Password: _
</code>

Credentials are provided by the system administrator. After successful authentication, a command shell (usually ''%%bash%%'') is opened.

<note important>
**Important:** Use the ''%%Ctrl+Alt+F1%%'' … ''%%Ctrl+Alt+F6%%'' key combinations to switch between virtual consoles.
</note>

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===== 2. Built-in documentation =====

VEOS includes an extensive built-in help system.

=== 2.1. The ''man'' utility ===

The ''%%man%%'' command (short for manual) is used to view manual pages for commands, configuration files, and other system objects.

^ Action ^ Command ^
| View help for the ''%%ls%%'' command | ''%%man ls%%'' |
| Search for a command by keyword | ''%%apropos <keyword>%%'' |
| Search for a command by keyword (short form) | ''%%man -k <keyword>%%'' |
| Help for the ''%%man%%'' utility itself | ''%%man man%%'' |

**Navigation inside a manual page:**

^ Key ^ Action ^
| ''%%Space%%'' | Go to the next page |
| ''%%q%%'' | Exit viewing mode |

=== 2.2. The ''info'' utility ===

Unlike linear ''%%man%%'' pages, the ''%%info%%'' system provides hypertext-style documentation.

^ Command ^ Action ^
| ''%%info%%'' | Display the list of all ''%%info%%'' documents in the system |
| ''%%info info%%'' | Open the navigation guide for ''%%info%%'' |
| ''%%h%%'' | Show navigation help (inside ''%%info%%'') |

----

===== 3. Software installation and updates =====

The ''%%dnf%%'' (or ''%%yum%%'') package managers are used to manage software. Installation and updates require superuser privileges.

=== 3.1. Basic package operations ===

^ Operation ^ Command (as root) ^
| Install a package from a repository | ''%%dnf install <package_name>%%'' |
| Remove a package | ''%%dnf remove <package_name>%%'' |
| Update all system packages | ''%%dnf update%%'' |
| Install a local ''%%rpm%%'' package | ''%%rpm -ih <path_to_file.rpm>%%'' |
| Update a local ''%%rpm%%'' package | ''%%rpm -Uh <path_to_file.rpm>%%'' |

**Example of installing the ''%%fastdpi%%'' (DPI) package:**
<code bash>
dnf install fastdpi
</code>

<note important>
VEOS is preconfigured with access to the official VAS Experts repositories, so company packages can be installed without additional repository configuration.
</note>

----

===== 4. Basic commands for working with the system =====

All commands listed in this section are standard Linux commands and can be executed from the command line.

<note>
Most short command options start with a single hyphen (''%%-l%%''), after which multiple letters can be specified consecutively (for example: ''%%ls -lF%%'' instead of ''%%ls -l -F%%'').
</note>

=== 4.1. User management ===

^ Command ^ Action ^ Note ^
| ''%%su -%%'' | Obtain superuser (root) privileges | The root password will be requested |
| ''%%exit%%'' | Exit the superuser session | Returns to the regular user |
| ''%%id%%'' | Display information about the current user | Shows UID, GID, and group list |
| ''%%id <login>%%'' | Display information about another user | |
| ''%%passwd%%'' | Change the current user's password | The old password must be entered |
| ''%%passwd <login>%%'' | Change another user's password | Only root can execute this |

=== 4.2. Navigation and file operations ===

^ Command ^ Description ^ Examples / Notes ^
| ''%%ls%%'' | View directory contents | ''%%ls -la%%'' — show all files with detailed information |
| ''%%cd%%'' | Change the current directory | ''%%cd /usr/bin%%'' — switch to an absolute path, ''%%cd ..%%'' — move one level up, ''%%cd -%%'' — return to the previous directory |
| ''%%pwd%%'' | Show the absolute path to the current directory | |
| ''%%mkdir <directory>%%'' | Create a new directory | ''%%mkdir -p path/to/dir%%'' — create a directory with parent directories |
| ''%%rmdir <directory>%%'' | Remove an empty directory | ''%%rm -rf%%'' is often used for non-empty directories |
| ''%%rm <file>%%'' | Remove a file | ''%%rm -i%%'' — request confirmation, ''%%rm -rf%%'' — recursive deletion **use with caution!** |
| ''%%cp <source> <target>%%'' | Copy a file or directory | ''%%cp -rp dir1 dir2%%'' — recursive copy preserving permissions |
| ''%%mv <source> <target>%%'' | Move or rename | ''%%mv file.txt dir/%%'' — move a file into a directory |
| ''%%cat <file>%%'' | Display file contents in the console | ''%%cat -n file.txt%%'' — with line numbering |
| ''%%head <file>%%'' | Display the first lines of a file | ''%%head -n 20 file.txt%%'' — show the first 20 lines |
| ''%%less <file>%%'' | View a file page by page | ''%%q%%'' — exit |

<note warning>
**Warning:** The ''%%rm%%'' and ''%%rmdir%%'' commands permanently delete files during normal operation, bypassing the Trash. Be especially careful with recursive deletion (''%%-r%%'').
</note>

=== 4.3. Searching for files and commands ===

^ Command ^ Description ^ Example ^
| ''%%grep <pattern> <file>%%'' | Search for a string in a file | ''%%grep error /var/log/messages%%'' |
| ''%%find [path] [expression]%%'' | Search for files by condition | ''%%find . -name "*.conf"%%'' — find all ''%%.conf%%'' files in the current directory |
| ''%%whereis <command>%%'' | Show the location of a program, source files, and documentation | ''%%whereis bash%%'' |
| ''%%which <command>%%'' | Show the full path to a command executable | ''%%which ls%%'' |

=== 4.4. Access permissions ===

^ Command ^ Description ^ Example ^
| ''%%chmod <mode> <file>%%'' | Change file permissions | ''%%chmod +x script.sh%%'' — make the file executable for everyone |
| ''%%chown <owner>:<group> <file>%%'' | Change the owner and group of a file | ''%%chown test:users file.txt%%'' |

=== 4.5. System and process monitoring ===

^ Command ^ Description ^ Example ^
| ''%%ps%%'' | Display the list of the current user's processes | ''%%ps aux%%'' — detailed list of all processes |
| ''%%kill <PID>%%'' | Stop a process by its identifier | ''%%kill -9 <PID>%%'' — force termination |
| ''%%df%%'' | Show disk space usage | ''%%df -h%%'' — human-readable format |
| ''%%du%%'' | Estimate disk space used by files and directories | ''%%du -sh ~/%%'' — total size of the home directory |
| ''%%&%%'' | Run a program in the background | ''%%./long_task.sh &%%'' |
| ''%%bg%%'' | Resume a stopped job in the background | |
| ''%%fg%%'' | Bring a background job to the foreground | |

----

===== 5. File archiving and compression =====

The **''%%tar%%'' command** is used to create archives (without compression). Additional programs (''%%gzip%%'', ''%%bzip2%%'', ''%%xz%%'') are used for archive compression.

^ Operation ^ Command ^
| Archive a directory | ''%%tar -cf <archive.tar> <directory>%%'' |
| Extract an archive | ''%%tar -xf <archive.tar>%%'' |
| Extract a compressed archive (''%%.tar.gz%%'' or ''%%.tgz%%'') | ''%%tar -xzf <archive.tar.gz>%%'' |
| Create a compressed ''%%.tar.gz%%'' archive | ''%%tar -czf <archive.tar.gz> <directory>%%'' |

**Example:**
<code bash>
# Archive the Documents directory into my_docs.tar
tar -cf my_docs.tar Documents/

# Extract a gzip-compressed archive into the current directory
tar -xzf archive.tar.gz
</code>

----

===== 6. Frequently asked questions (FAQ) =====

**Question:** How do I obtain superuser (root) privileges?\\  
**Answer:** Run the ''%%su -%%'' command. You will be prompted for the ''%%root%%'' user password. Use the ''%%exit%%'' command to return to the regular user.

**Question:** How do I officially install a VAS Experts package?\\  
**Answer:** ''%%dnf install <package_name>%%''. Search for packages using: ''%%dnf search <keyword>%%''.

**Question:** Where can I find help for the ''%%ls%%'' command?\\  
**Answer:** Use the built-in documentation: ''%%man ls%%'' or ''%%info ls%%''.

**Question:** How do I run a program in the background?\\  
**Answer:** Add the ''%%&%%'' symbol at the end of the command, for example: ''%%./backup_script.sh &%%''.

**Question:** Can I search within file contents?\\  
**Answer:** Yes, use the ''%%grep%%'' command. Example: ''%%grep -r "error" /var/log/%%''.

----

<details>
<summary>📌 Technical document information</summary>

**Document last reviewed:** 2026-05-12\\  
**Applicable VEOS version:** 8.6 and later\\  
**Author:** VAS Experts

</details>