What is the usage of C language string functions?

In the C language, there are many string functions available for handling strings, some common string functions include:

1. strlen(): used to get the length of a string, returning the number of characters in the string.
2. strcmp() is used to compare two strings to see if they are equal. It returns 0 if they are equal, and a non-zero value if they are not equal.
3. strcpy(): Copy one string to another string.
4. strcat() appends one string to the end of another.
5. strncpy() is used to copy a portion of one string to another string.
6. strstr(): Search for the first occurrence of a string within another string and return a pointer to that position.
7. strchr() is a function that searches for the first occurrence of a specified character in a string and returns a pointer to the position of that character.
8. strtok() is used to divide a string into multiple sub-strings and returns a pointer to each sub-string.

The above are just some common string functions, there are many other functions available for use. These functions can help us operate and manipulate strings more conveniently.