In Bash scripting, file permissions are managed using chmod command. It changes the access permissions of file system objects. The syntax is ‘chmod [options] mode file’. Mode defines who can do what to a file. It’s represented by three characters: user(u), group(g) and others(o). Each character has read(r), write(w) and execute(x) permissions. Numeric values 4, 2, and 1 represent these respectively. For example, ‘chmod u=rwx,g=rx,o=r myfile’ gives full permissions to user, read and execute to group, and only read to others. Alternatively, numeric representation like ‘chmod 754 myfile’ can be used where 7 (rwx for user), 5 (rx for group) and 4 (r for others) are set. To recursively change permissions of files in a directory, use ‘-R’ option.
