Update Linux

sudo apt dist-upgrade -y

Running Shell Script

./script_name.sh
# OR
sh script_name.sh
# OR
bash ./script_path.sh

File Level Commands

# cat
## reads the contents of a file in console
cat filename.txt

## override the contents of another file
### if the destination file does not exist, then the command will create the file
cat source.txt > destination.txt

## concatenate multiple files to one
cat source1.txt source2.txt > destination.txt

# grep
grep "search_string" filename

cat file_name.txt | grep “keyword”

`grep`

By default, the grep command outputs entire lines that contain the match.

returns the lines of the text file which contain the matching search string.

A line in a text file is a sequence of characters followed by a line break.

Search

Command line utility for searching plain-text data sets for lines that match a regex

grep

Rename OR Move (`mv`)

Rename

Change file's old_file_name to new_file_name in current directory

Also works for directory names
- You should use gmv when you are inside of a git repository or Git will lose track of the changes (especially in directory with submodules)

mv old_file_name new_file_name

Move

When moving a directory, mv command also works

mv dir_name new_location/dir_name

Name with Spaces

Escape out the spaces with the \ escape character before the special character

# Moving "Learning Python Programming - Working Files"
mv Learning\ Python\ Programming\ -\ Working\ Files

Copy

Copy the contents of a file or the output of a command to the system clipboard

# copying the contents of a file
pbcopy < file.txt

# copying the output of a command
ls -l | pbcopy

Dot Command

Every directory in Unix-like OS contains (as a minimum), an object represented by a single dot and another represented by a double dot.

Single dot (.) represents the directory itself and the double dot (..) refers to its parent directory.

These dots are created in every directory.

`.find`

e.g. find and list all .DS_Store in current folder recursively

find . -name ".DS_Store"

Delete all files that are recursively matching from current directory.

-type f is a tag to filter only for files, excluding directories

find . -name ".DS_Store" -type f -delete

`$home`

Represents user's home directory regardless of where it is being called from.

Home can be different per OS (e.g. Mac and Linux have different home directories)

$home is same as ~.

`std`

`top`

top

Shows a dynamic, real-time view of running processes and kernel-managed tasks in Linux.

`chmod`

Sets the permissions of files and directories.

chmod u=rwx,g=rx,o=r myfile

the user can read, write, and execute it
members of your group can read and execute it
others may only read it

Filesystem level operations

# ls
ls # list contents of current directory

ls -a # list all contents in default ls-style

ls -la # in vertical list style
la

# touch
touch file_name.extension_name # create a new file

# cp
## The cp command allows you to duplicate files or directories from one part of the file system to another

cp source_file_name target_file_name

# rm
rm file_name # remove a file
rm -r directory_name # remove a directory recursively
rm -rf directory_name # forcefully remove a directory recursively

# zip

## zips the destination path recursively to a single `.zip` file.
zip [options] [file_name.zip] [files_names]

# recursively zip files in path to a single file `output.zip`
zip -r output.zip ./path-to-source

Commands