The bash printf command is a tool used for creating formatted output. Here are some examples of some of the most useful printf format specifiers:

1. %s - used to print a string. For example:

   name="John"
   printf "Hello, %s!\n" $name
   

   Output: Hello, John!

2. %d - used to print an integer. For example:

   x=5
   printf "%d\n" $x
   

   Output: 5

3. %f - used to print a floating-point number. For example:

   x=3.14159
   printf "%.2f\n" $x
   

   Output: 3.14

4. %x - used to print an integer in hexadecimal format. For example:

   x=255
   printf "%x\n" $x
   

   Output: ff

5. %o - used to print an integer in octal format. For example:

   x=255
   printf "%o\n" $x
   

   Output: 377

6. %c - used to print a single character. For example:

   x='A'
   printf "%c\n" $x
   

   Output: A

7. %b - used to print an integer in binary format. For example:

   x=5
   printf "%b\n" $x
   

   Output: 101

8. %e - used to print a floating-point number in scientific notation. For example:

   x=3.14159
   printf "%e\n" $x
   

   Output: 3.141590e+00

Reference:

1. printf man page
2. Bash printf - How to Print a Variable in Bash