| /bin | Essential command binaries (programs) are stored here (bash, ls, mount,tar, etc.) |
| /boot | Static files of the boot loader. |
| /dev | Device files. In Linux, hardware devices are acceessd just like other files, and they are kept under this directory. |
| /etc | Host-specific system configuration files. |
| /home | Location of users' personal home directories (e.g. /home/susan). |
| /lib | Essential shared libraries and kernel modules. |
| /Proc | Process information pseudo-filesystem. An interface to kernel data structures. |
| /root | The root (superuser) home directory. |
| /sbin | Essential system binaries (fdisk, fsck, init, etc). |
| /tmp | Temporary files. All users have permission to place temporary files here. |
| /usr | The base directory for most shareable, read-only data (programs, libraries,documentation, and much more). |
| /var | Variable data: mail and printer spools, log files, lock files, etc. |
Basic Commands For Navigation
| ESX Command | DOS/Windows Command | Description |
| pwd | cd | “Print Working Directory”. Shows the current location in the directory tree. |
| cd | cd,chdir | “Change Directory”. When typed all by itself, it returns you to your home directory. |
| cd directory | cd directory | Change into the specified directory name. Example: cd /usr/src/linux |
| cd ~ | . | “~” is an alias for your home directory. It can be used as a shortcut to your “home”, or other directories relative to your home. |
| cd.. | cd.. | Move up one directory. For example, if you are in /home/vic and you type “cd ..”, you will end up in /home. |
| cd - | . | Return to previous directory. An easy way to get back to your previous location! |
| Is | Dir /w | List all files in the current directory, in column format. |
| Is directory | Dir directory | List the files in the specified directory. Example: ls /var/log |
Special Characters
| Character | Description |
| \ | Escape character. If you want to reference a special character, you must “escape” it with a backslash first. Example: touch /tmp/filename\* |
| / | Directory separator, used to separate a string of directory names. Example: /usr/src/linux |
| . | Current directory. Can also “hide” files when it is the first character in a filename. |
| .. | Parent Directory |
| ~ | User's Home Directory |
| * | Represents 0 or more characters in a filename, or by itself, all files in a directory. Example: pic*2002 can represent the files pic2002, picJanuary2002, etc. |
| ? | Represents a single character in a filename. Example: hello?.txt can represent hello1.txt, helloz.txt, but not hello22.txt |
| [] | Can be used to represent a range of values, e.g. [0-9], [A-Z], etc. Example: hello[0-2].txt represents the names hello0.txt,hello1.txt, and hello2.txt |
| | | “Pipe”. Redirect the output of one command into another command. Example: ls | more |
| > | Redirect output of a command into a new file. If the file already exists, over-write it. Example: ls > myfiles.txt |
| >> | Redirect the output of a command onto the end of an existing file. Example: echo .Mary 555-1234. >> phonenumbers.txt |
| < | Redirect a file as input to a program. Example: more < phonenumbers.txt |
| ; | Command separator. Allows you to execute multiple commands on a single line.Example: cd /var/log ; less messages |
| && | Command separator as above, but only runs the second command if the first one finished without errors. Example: cd /var/logs && less messages |
| & | Execute a command in the background, and immediately get your shell back. Example: find / -name core > /tmp/corefiles.txt & |
Working with Files and Directories
| ESX Command | DOS/Windows Command | Description |
| Cat | type | Display the contents of a text file on the screen. For example: cat mp3files.txt |
| Head | - | Display the first few lines of a text file. Example: head /etc/services |
| Tail | - | Display the last few lines of a text file. Example: tail /etc/services |
| tail-f | - | Display the last few lines of a text file, and then output appended data as the file grows (very useful for following log files!). Example: tail -f /var/log/messages |
| Cp | Copy | Copies a file from one location to another. Example: cp mp3files.txt /tmp |
| mv | Move,ren,rename | Moves a file to a new location, or renames it. For example: mv mp3files.txt /tmp |
| rm | Del | Delete a file. Example: rm /tmp/mp3files.txt |
| mkdir | md | Make Directory. Example: mkdir /tmp/myfiles/ |
| rmdir | rd,Rmdir | Remove Directory. Example: rmdir /tmp/myfiles/ |
Find/Search things
| Linux Command | Description |
| Which | Shows the full path of Shell Commands found in your path.For example,if u want to know exactly where the "grep Command is located on the file system,you cantype "Which grep".The Output should be something like /bin/grep. |
| where is | Locates the Program,Source code,and manual page for a command(if all information is available).For example, to find out where "1s" and its main page are, type "Whereis 1s".The output will look something like: 1s:/bin//1s/usr/share/man/man1/1s.1.gz |
| locate | A quick way to search for files anywhere on the file system.For example,you can find all files and directories that contain the name "mozilla"by typing: locate mozilla |
| find | A very powerful command,but sometimes tricky to use.It can be used to search for files matching certain patterns as well as many other types of searche.A simple example is: find . -name \*mp3 This example starts searching in the current directory"." and all sub directories looking for files with"mp3"at the end od their names |
Informational Commands
| Linux Command | Description |
| ps | Links currently running process(programs). |
| w | Show who is logged on and what they are doing. |
| id | Print your User-id's and Group id's. |
| df | Report File system disk space usage("DiskFree" is how I remember it) |
| du | Disk Usage in a Particular Directory."du -s" provides a summary for current directory. |
| top | Displays CPU Processes in a full screen GUI.A great way to see the activity on your computer in real time.Type "Q" to quit. |
| free | Displays amount of free and used memory in the system. |
| cat/proc/cpuinfo | Displays information about your CPU. |
| cat/proc/meminfo | Displays lots of information about current memory Usage |
| uname -a | Prints system information to the screen(Kernel version,machine type,etc.,). |
Other Utilities
| Linux Command | Description |
| Clear | Clear the Screen |
| echo | Display text on the screen.Mostly useful when writing shell scripts.For example: echo"Hello World" |
| more | Display a file, or program output onpage at a time.Examples: more mp3files.txt ls -la | more. |
| less | An improved replacement for "more" command".Allows you to scroll backwards as well as forwards. |
| grep | Search for a pattern in a file or program output.For example to find out which TCP network is used by the "NFS" service,You can do this: grep "nfs" /etc/services This looks for any line that contains the string "nfs" in the file "/etc/services" and displays only those lines. |
| lpr | Print a file or program output.Examples: lpr mp3files.txt - Prints the mp3files.txt files. ls -la | lpr -Prints the output of the "ls -la" command. |
| sort | Sort a file or Program Output.Examples: sort mp3files.txt. |
| su | "Switch user".Allows you to switch to another user account temporarily.The default account to switch to is the root/superuser account.Examples: su -Switch to root account. su- -Switch to root and log in with root's environment. su larry-Switch to larry's account. |
