os.WriteFile()

Writing into Files

WriteFile writes data to the named file, creating it if necessary. If the file does not exist, WriteFile creates it with permissions perm (before umask); otherwise WriteFile truncates it before writing, without changing permissions. Since WriteFile requires multiple system calls to complete, a failure mid-operation can leave the file in a partially written state.

Paramteres: file, []byte and permission.

Example usage:

os.WriteFile("balance.txt", []byte(balanceText), 0644)

Don't forget to create a new variable with Sprintf to later convert your variable into a []byte.

More information about the given 0644 permission:

The "0644" is a representation of file permissions in octal notation, commonly used in Unix and Unix-like operating systems. Let's break it down:

1. The leading "0" indicates that this is an octal number.

2. The remaining three digits (644) represent permissions for three different categories of users:

   • The first digit (6): Owner permissions

   • The second digit (4): Group permissions

   • The third digit (4): Others (everyone else) permissions

3. Each digit is the sum of the following values:

   • 4: Read permission

   • 2: Write permission

   • 1: Execute permission

So, 0644 translates to:

• Owner (6): Read (4) + Write (2) = 6

• Group (4): Read (4)

• Others (4): Read (4)

In symbolic notation, this would be written as "-rw-r--r--", where:

• The first "-" represents the file type (in this case, a regular file)

• "rw-" represents owner permissions (read and write)

• "r--" represents group permissions (read only)

• "r--" represents others permissions (read only)

This permission set is common for regular files that should be readable by everyone but only writable by the owner.