Learn Python in Tamil | பைதான் மொழியைக் கற்றுக்கொள்ளுங்கள் – Python programming language introduction | பைத்தான் அறிமுகம்
கணினி, மொபைல், இயந்திரங்கள் மின்னணு சாதனங்கள், அது எந்த மனிதனின் மொழியையும் புரிந்து கொள்ளவில்லை. அது என்ன புரிந்துகொள்கிறது? இது இயந்திர மொழியைப் புரிந்து கொள்ள முடியும் (இது 0 மற்றும் 1 இன் தவிர வேறு ஒன்றும் இல்லை – binary code)
High level & Low level மொழிகள்
High level மொழிகள்- எளிய ஆங்கில வாக்கியம் இயந்திரத்திற்கு வழிமுறைகளை வழங்க பயன்படுத்தப்படுகிறது. Low level மொழிகளின் எடுத்துக்காட்டு #Java, #Python மற்றும் பல Low level 0 மற்றும் 1 கள் செயல் அல்லது வழிமுறைகளைச் செய்ய இயந்திரத்தில் ஊட்டப்படுகின்றன. (Assembly மொழி மற்றும் Machine மொழிகள்)
High level to low level or machine language “Interpreter” பயன்படுத்தப்படுகிறது. எளிய ஆங்கிலத்தை 0 மற்றும் 1 க்கு மாற்ற டெவலப்பர்கள் அல்லது புரோகிராமர்களால் இந்த interpreter எழுதினார்.
பைதான் “குடியோ வான் ரோஸம்” என்பவரால் உருவாக்கப்பட்டது மற்றும் 1991 ஆம் ஆண்டில் வெளியிடப்பட்டது. வலை வடிவமைப்பு, மென்பொருள் மேம்பாடு, கணினி ஸ்கிரிப்டிங், கணிதம் மற்றும் பல இடங்களில் பைதான் பயன்படுத்தப்படுகிறது.
Computer, mobile, machines are electronic devices, it does not understand any human’s language.
Then what does computer’s understands?
Computer’s can understand only machine language, which is nothing but 0’s and 1’s – Binary code
High level or Low level programming languages
High level – It’s simple English sentence which are used for providing instructions to the machines.
Example: #Java, #Python are some of High level programming languages.
Low level – Direct 0’s and 1’s are feed into the machine to perform the action or instructions. (Assembly language and machine languages)
Interpreter
It is used for converting the High level to Low level or machine, Interpreter’s were also written by developers or programmers, to convert the simple English sentence to 0’s and 1’s.
Gudio van Rossum has created Python and released in the year 1991. It is also used in Web designing, Software development, System scripting, Mathematics and many more places.
Options : (Below are frequently used options with grep command) -i Ignores case -n Print the line number -c Count of matched pattern (Will not print the search line, rather it just prints the count) -r Will search folders for matching text. -v non-matched lines are printed
Try for yourself:
1) Search for any string and print count hint: use -c 2) Search entire folder for match pattern with , (This is special symbol) hint: “\,” 3) Search string by ignoring the case and also search for multiple string in a file hint: use -v and in search string you need to split using | for multiple search string.
Here we’re going to talk all about Permissions (CHOWN) in Unix?
When it comes to access for reading,writing or executing files in unix we need to play around with the permissions! So today we are going to talk all about ownership and permissions (chown).
Ownership and Permissions are important thing in unix, when it comes to files and folders access.
Changing ownership for files and folders using CHOWN
Command Usage:
chown user:group filename (Changing ownership for user and group)
chown :group filename (Only to the group)
chown user filename (Only the user)
chown user:group foldername -R (For folders and sub directory use -R)
Note: -R to apply the changes to the sub directories and files within the folder.
owner – User who created the file or folder group – User belong to the group (groups example: admin, author, sysadmin, root, local, itadmin) – varies from system to system
Try for yourself: 1) Change both owner and group from root to user1 or user1 to root hint: chown root:root file1.txt 2) Try to change for folder and its sub content (incl. sub directories) chown root:aryanz_co_in folder1 -R
Here we’re going to talk all about Permissions in Unix terminal?
When it comes to reading, writing or executing files in unix we need to play around with the permissions! So today we are going to talk all about permissions in unix terminal (chmod).
Permissions are important thing in unix, when it comes to files and folders access.
How to change directory permissions in Linux
To change directory permissions in Linux, use the following:
chmod +rwx filename to add permissions.
chmod -rwx directoryname to remove permissions.
chmod +x filename to allow executable permissions.
chmod -wx filename to take out write and executable permissions.
Note that “r” is for read, “w” is for write, and “x” is for execute.
This only changes the permissions for the owner of the file.
How to Change Permissions in Numeric Code in Linux – Watch it in below video
You may need to know how to change permissions in numeric code in Linux, so to do this you use numbers instead of “r”, “w”, or “x”.
0 = No Permission
1 = Execute
2 = Write
4 = Read
Basically, you add up the numbers depending on the level of permission you want to give.
Permission numbers are:
0 = —
1 = –x
2 = -w-
3 = -wx
4 = r-
5 = r-x
6 = rw-
7 = rwx
For example:
chmod 777 foldername will give read, write, and execute permissions for everyone.
chmod 700 foldername will give read, write, and execute permissions for the user only.
chmod 327 foldername will give write and execute (3) permission for the user, w (2) for the group, and read, write, and execute for the users.
How to Change Directory Permissions in Linux for the Group Owners and Others
The command for changing directory permissions for group owners is similar, but add a “g” for group or “o” for users and “u” for owners:
To change directory permissions for everyone, use “u” for owners, “g” for group, “o” for users, and “ugo” or “a” (for all).
chmod ugo+rwx foldername to give read, write, and execute to everyone.
chmod a=r foldername to give only read permission for everyone.
As you can see, there are several options when it comes to permissions. You have the capability to dictate usability among users. While it may be easier to just give all permission to everyone, it may end up biting you in the end. So choose wisely.
