What is the purpose of the IFS in shell commands?

IFS is a built-in variable in Shell, which specifies the delimiter used to separate fields. It controls how Shell parses command arguments and input data.

In Shell, when commands or scripts need to process data with multiple fields, IFS can be used to split the input data into multiple fields, and then process each field. By default, IFS is set to a string containing spaces, tabs, and newline characters, so Shell will split the input data based on these characters.

One option is to change the separator by modifying the value of IFS. For example, you can set IFS to a comma and then use the comma to separate the fields of input data. The following command can be used to modify the value of IFS:

IFS=,

# 示例：将逗号分割的字符串赋值给数组
data="apple,banana,grape"
array=($data)

In addition to using IFS in commands, IFS can also be used in shell scripts to process file contents, command outputs, and more. By modifying the value of IFS, different types of data can be handled flexibly.