> For the complete documentation index, see [llms.txt](https://dev-patel-1.gitbook.io/notes/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dev-patel-1.gitbook.io/notes/back-end/bash.md). # Bash ## Core Commands | Key/Command | Description | | --------------- | ------------------------------------------------------------------------- | | cd \[folder] | Change directory e.g. `cd Documents` | | cd | Home directory | | cd \~ | Home directory | | cd / | Root of drive | | cd - | Previous directory | | ls | Short listing (just names) | | ls -l | Long listing (names + extra info) | | ls -a | Listing incl. hidden files | | 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] | Opens the file using the vim editor | | clear | Clears the 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-b] | Run command B if A failed | | \[command-a] & | Run command A in background | ## 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’ | | !\[value]:p | Print to the console the last command typed that starts with ‘value’ | | !! | Execute the last command typed | | !!:p | Print to the console the last command typed | ## File Management | Key/Command | Description | | -------------------------- | -------------------------------------------------------------- | | touch \[file] | Create a 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] | Paste clipboard contents into file, `pbpaste > paste-test.txt` | ## Directory (Folder) 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 | | less \[file] | Output file 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. `find /Users -name "file.txt"` | | grep \[search\_pattern] \[file] | Search for all lines that contain the pattern, e.g. `grep "Tom" file.txt` | | grep -r \[search\_pattern] \[dir] | Recursively search in all files in specified directory for all lines that contain the pattern | | grep -v \[search\_pattern] \[file] | Search for all lines that do NOT contain the pattern | | grep -i \[search\_pattern] \[file] | Search for all lines that contain the case-insensitive pattern | | mdfind \[search\_pattern] | Spotlight search for files (names, content, other metadata), e.g. `mdfind skateboard` | | mdfind -onlyin \[dir] -name \[pattern] | Spotlight search for files named like pattern in the given directory | ## Shortcuts | Key/Command | Description | | --------------- | --------------------------------------------------------------------------------------- | | Ctrl + A | Go to the beginning of the line you are currently typing on. | | Ctrl + E | Go to the end of the line you are currently typing on. | | Ctrl + L | Clears the Screen | | Cmd + K | Clears the Screen | | Ctrl + U | Cut everything backwards to beginning of line | | Ctrl + K | Cut everything forward to end of line | | Ctrl + W | Cut one word backwards using white space as delimiter | | Ctrl + Y | Paste whatever was cut by the last cut command | | Ctrl + H | Same as backspace | | Ctrl + C | Kill whatever you are running. Also clears everything on current line | | Ctrl + D | Exit the current shell when no process is running, or send EOF to a the running process | | Ctrl + Z | Puts whatever you are running into a suspended background process. fg restores it | | Ctrl + \_ | Undo the last command. (Underscore. So it's actually Ctrl + Shift + minus) | | Ctrl + T | Swap the last two characters before the cursor | | Ctrl + F | Move cursor one character forward | | Ctrl + B | Move cursor one character backward | | Option + → | Move cursor one word forward | | Option + ← | Move cursor one word backward | | Esc + T | Swap the last two words before the cursor | | Esc + Backspace | Cut one word backwards using none alphabetic characters as delimiters | | Tab | Auto-complete files and folder names | ## 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 | Misc: * ***awk*** - basically a general-purpose scripting language designed mostly used for printing. * ***sed*** - 'stream editor' used for file operations like searching, find and replace, insertion or deletion. * ***lsof*** - 'list open files' gives the info to find out the files which are opened by which process. * ***curl*** - used for transferring data from/to a server designed to work without user interaction * ***wget*** - used for downloading files from the web * provides a number of options allowing you to download multiple files, resume downloads, limit the bandwidth, recursive downloads, download in the background, mirror a website, and much more * ***tail*** - print the last N number of data of the file; by default it prints the last 10 lines. * ***head*** - print the first N number of data of the file; by default it prints the first 10 lines. * ***ssh*** - 'secure shell' protocol used to securely connect to a remote server/system * transfers the data in encrypted form between host and client. SSH runs at TCP/IP port 22 * ***kill*** - used to terminate processes manually; sends a signal to a process which terminates the process