Unix toolbox

Unix Toolbox

This document is a collection of Unix/Linux/BSD commands and tasks which are useful for IT work or for advanced users. This is a practical guide with concise explanations, however the reader is supposed to know what s/he is doing.

1. System
2. Processes
3. File System
4. Network
5. SSH SCP
6. VPN with SSH
7. RSYNC
8. SUDO
9. Encrypt Files10. Encrypt Partitions
11. SSL Certificates
12. CVS
13. SVN
14. Useful Commands
15. Install Software
16. Convert Media
17. Printing
18. Databases
19. Disk Quota
20. Shells
21. Scripting
22. Programming
23. Online Help

System

HARDWARE | STATISTICS | USERS | LIMITS | RUNLEVELS | ROOT PASSWORD | COMPILE KERNEL | REPAIR GRUB
Running kernel and systeminformation
# uname -a # Get the kernel version (and BSD version)
# lsb_release -a # Full release info of any LSB distribution
# cat /etc/SuSE-release # Get SuSE version
# cat /etc/debian_version # Get Debian version
Use /etc/DISTR-release with DISTR= lsb (Ubuntu), redhat, gentoo, mandrake, sun (Solaris), and so on. See also/etc/issue.
# uptime # Show how long the system has been running + load
# hostname # system's host name
# hostname -i # Display the IP address of the host. (Linux only)
# man hier # Description of the file system hierarchy
# last reboot # Show system reboot historyHardware Informations

Kernel detected hardware
# dmesg # Detected hardware and boot messages
# lsdev # information about installed hardware
# dd if=/dev/mem bs=1k skip=768 count=256 2>/dev/null | strings -n 8 # Read BIOS

Linux

# cat /proc/cpuinfo # CPU model
# cat /proc/meminfo # Hardware memory
#grep MemTotal /proc/meminfo # Display the physical memory
# watch -n1 'cat /proc/interrupts' # Watch changeable interrupts continuously
# free -m # Used and free memory (-m for MB)
# cat /proc/devices # Configured devices
# lspci -tv # Show PCI devices
# lsusb -tv # Show USB devices
#lshal # Show a list of all devices with their properties
# dmidecode # Show DMI/SMBIOS: hw info from the BIOS

FreeBSD

# sysctl hw.model # CPU model
# sysctl hw # Gives a lot of hardware information
# sysctl vm # Memory usage
# dmesg | grep "real mem" #Hardware memory
# sysctl -a | grep mem # Kernel memory settings and info
# sysctl dev # Configured devices
# pciconf -l -cv # Show PCI devices
# usbdevs -v # Show USB devices
# atacontrol list # Show ATA devices
# camcontrol devlist -v # Show SCSI devices

Load, statistics andmessages

The following commands are useful to find out what is going on on the system.
# top # display and update the top cpu processes
# mpstat 1 # display processors related statistics
# vmstat 2 # display virtual memory statistics
# iostat 2 # display I/O statistics (2 s intervals)
#systat -vmstat 1 # BSD summary of system statistics (1 s intervals)
# systat -tcp 1 # BSD tcp connections (try also -ip)
# systat -netstat 1 # BSD active network connections
# systat -ifstat 1 # BSD network traffic through active interfaces
# systat -iostat 1 # BSD CPU and and disk throughput
# tail -n...