Blog. Infrastructure: Windows, Linux, Unix, Bash
BASH COMMANDS Needs to know
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CORE BASH COMMANDS
All commands in one place help developers to do routine work faster.
| Key/Command | Description |
|---|---|
| cd | Return to Home directory |
| cd [folder] |
Change directory e.g.
|
| cd / | Root of drive |
| cd - | Previous directory |
| ls | Short listing |
| ls -l | Long listing |
| ls -ap | -a Listing incl. hidden files -p. The"\" at the and for folders |
| ls -lh | Long listing with Human readable file sizes |
| ls -R | Entire content of folder recursively |
| sudo [command] | Run command with the security privileges of the superuser (Super User DO) |
| open [file] | Opens a file ( as if you double clicked it ) |
| top | Displays active processes. Press q to quit |
| nano [file] | Opens the file using the nano editor |
| vim [file] | vi [file] | Opens the file using the vim editor |
| clear | Clear screen |
| reset | Resets the terminal display |
CHAINING COMMANDS
| Key/Command | Description |
|---|---|
| [command-a]; [command-b] | Run command A and then B, regardless of success of A |
| [command-a] && [command-b] | Run command B if A succeeded |
| [command-a] | |
| [command-a] & | Run command A in background |
PIPING COMMANDS
| Key/Command | Description |
|---|---|
| [command-a] | [command-b] |
Run command A and then pass the result to command B e.g Example: ps -ef | grep java |
COMMAND HISTORY
| Key/Command | Description |
|---|---|
| history n | Shows the stuff typed – add a number to limit the last n items |
| Ctrl + r | Interactively search through previously typed commands |
| ![value] | Execute the last command typed that starts with ‘value’ |
| !! | Execute the last command typed |
FILE MANAGEMENT
| Key/Command | Description |
|---|---|
| touch [file] | Create new file |
| pwd | Full path to working directory |
| . | Current folder, e.g. ls . |
| .. | Parent/enclosing directory, e.g. ls .. |
ls -l .. |
Long listing of parent directory |
cd ../../ |
Move 2 levels up |
| cat | Concatenate to screen |
| rm [file] | Remove a file, e.g. rm data.tmp |
| rm -i [file] | Remove with confirmation |
| rm -r [dir] | Remove a directory and contents |
| rm -f [file] | Force removal without confirmation |
| cp [file] [newfile] | Copy file to file |
| cp [file] [dir] | Copy file to directory |
| mv [file] [new filename] | Move/Rename, e.g. mv file1.ad /tmp |
| pbcopy < [file] | Copies file contents to clipboard |
| pbpaste | Paste clipboard contents |
| pbpaste > [file] | Past clipboard contents into file, pbpaste > paste-test.txt |
DIRECTORY MANAGEMENT
| Key/Command | Description |
|---|---|
| mkdir [dir] | Create new directory |
| mkdir -p [dir]/[dir] | Create nested directories |
| rmdir [dir] | Remove directory ( only operates on empty directories ) |
| rm -R [dir] | Remove directory and contents |
| [command] | [command] | Allows to combine multiple commands that generate output, e.g. cat data.txt | pbcopy |
| less | Output content delivered in screensize chunks |
| [command] > [file] | Push output to file, keep in mind it will get overwritten |
| [command] >> [file] | Append output to existing file |
| [command] < [file] | Tell command to read content from a file |
SEARCH
| Key/Command | Description |
|---|---|
| find [dir] -name [search_pattern] |
Search for files, e.g. sudo find . -print | grep -i '.*[.]xml' |
| grep [search_pattern] [file] | Search for all lines that contain the pattern, e.g. grep "Tom" file.txt |
| grep -r [search_pattern] [file] |
Recursively search for all lines that do not contain the pattern grep -lr "text to find" * grep this_word this_file.txt |
| grep -v [search_pattern] [file] | Search for all lines that do NOT contain the pattern |
HELP
| Key/Command | Description |
|---|---|
| [command] -h | Offers help |
| [command] —help | Offers help |
| info [command] | Offers help |
| man [command] | Show the help manual for [command] |
| whatis [command] | Gives a one-line description of [command] |
| apropos [search-pattern] | Searches for command with keywords in description |
OTHER
| Key/Command | Description |
|---|---|
| sed replace word / string syntax |
Replace sed -i 's/old-word/new-word/g' *.txt Delete lines containing '#' comment character: initial=( `cat "$startfile" | sed -e '/#/d' | tr -d '\n' |\ # Delete lines containing '#' comment character. sed -e 's/\./\. /g' -e 's/_/_ /g'` ) # Excerpted from life.sh script |
| sleep 60s | Wait 60 sec |
| container_id=$(sudo docker ps -a -q -f="name=devstack") | Use variable in the bash script |
|
sudo yum install -y python-pip sudo pip install pyyaml |
Install something: Install python pip |
| yum install telnet | Install telnet |
| netstat -anp tcp | grep 3000 |
Check who does use the port |