String constants

A string constant is a sequence ofzero or morecharacters enclosed in double quotation marks. A string constant can be of any length, and they can have any of the possible 8-bit ASCII characters.These string constants can be stored in variables or appear literally as string constants, such as "River" or " ".

For example, if we want to print those records from cars.dat that contain the maruti string in the first field, we have to enclose the maruti string in double quotes while performing the match as follows:

$ awk '$1 == "maruti" {print}' cars.dat

The output of the execution of the preceding code is as follows:

maruti          swift       2007        50000       5
maruti          dezire      2009        3100        6
maruti          swift       2009        4100        5
maruti          esteem      1997        98000       1

• Null string: The string that contains no character is known as a null string, such as "".
• Substring: The contiguous sequence of zero or more characters within...