Question 1

What does chmod mean?

Accepted Answer

chmod stands for 'change mode' — the Unix command for changing file and directory permissions. Permissions control which users (owner, group, others) can read, write, or execute a file. The command accepts permissions in octal notation (e.g., chmod 755) or symbolic notation (e.g., chmod u+x).

Question 2

What does chmod 755 mean?

Accepted Answer

chmod 755 sets permissions to rwxr-xr-x: the owner can read, write, and execute (7 = 4+2+1); group and others can read and execute but not write (5 = 4+1). This is the standard permission for public directories and executables on a web server. chmod 644 (rw-r--r--) is standard for regular files.

Question 3

What is the difference between octal and symbolic chmod?

Accepted Answer

Octal chmod (e.g., chmod 755) sets all three permission sets at once using a 3-digit number where each digit is the sum of read (4), write (2), and execute (1). Symbolic chmod (e.g., chmod u+x, chmod go-w) modifies specific bits without affecting others. Use octal to set exact permissions; use symbolic to add or remove individual bits.

Question 4

What chmod permissions should web server files have?

Accepted Answer

Standard web server permissions: directories should be 755 (rwxr-xr-x) so the server can traverse them; static files (HTML, CSS, JS, images) should be 644 (rw-r--r--); secret files like .env should be 600 (rw-------) so only the owner can read them. Never use 777 on a production server.

أدوات مجانية لمطوري الويب

حاسبة chmod

الأذونات

الترميز الثماني

الترميز الرمزي

الإعدادات المسبقة الشائعة

أمر chmod

الملخص

كيف تعمل حاسبة chmod

ما الذي تفعله الأداة

حالات استخدام شائعة للمطورين

شرح تنسيق الأذونات

المزالق الشائعة والحالات الطرفية

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