C strcmp Function Guide

The strcmp function is used to compare if two strings are the same, its functions include:

1. Compare the sizes of two strings by comparing the characters in each string one by one in alphabetical order, and return the result of the comparison.
2. Check if two strings are equal. Return 0 if they are, otherwise return a non-zero value.
3. You can specify the length of the comparison, such as comparing only the first n characters of the string.
4. It can be used to sort an array of strings by passing a comparison function pointer to the qsort function.
5. You can compare case-insensitive strings by using a custom comparison function.

In conclusion, the strcmp function is mainly used for comparing strings to determine their relative order or equality.