C – string.h library functions

All C inbuilt functions which are declared in string.h header file are given below. The source code for string.h header file is also given below for your reference.

List of inbuilt C functions in string.h file:

S.no	string functions	Description
1	strcat(str1, str2)	Concatenates str2 at the end of str1.
2	strcpy(str1, str2)	Copies str2 into str1
3	strlen(strl)	gives the length of str1.
4	strcmp(str1, str2)	Returns 0 if str1 is same as str2. Returns <0 if strl < str2. Returns >0 if str1 > str2.
5	strchr(str1,char)	Returns pointer to first occurrence of char in str1.
6	strstr(str1, str2)	Returns pointer to first occurrence of str2 in str1.
7	strcmpi(str1,str2)	Same as strcmp() function. But, this function negotiates case.  “A” and “a” are treated as same.
8	strdup()	duplicates the string
9	strlwr()	converts string to lowercase
10	strncat()	appends a portion of string to another
11	strncpy()	copies given number of characters of one string to another
12	strrchr()	last occurrence of given character in a string is found
13	strrev()	reverses the given string
14	strset()	sets all character in a string to given character
15	strupr()	converts string to uppercase
16	strtok()	tokenizing given string using delimiter
17	memset()	It is used to initialize a specified number of bytes to null or any other value in the buffer
18	memcpy()	It is used to copy a specified number of bytes from one memory to another
19	memmove()	It is used to copy a specified number of bytes from one memory to another or to overlap on same memory.
20	memcmp()	It is used to compare specified number of characters from two buffers
21	memicmp()	It is used to compare specified number of characters from two buffers  regardless of the case of the characters
22	memchr()	It is used to locate the first occurrence of the character in the specified string