C String Functions

C programming provides several inbuilt functions for string to make our programming crystal clear because several lines of coding will be reduced to a word by using standard inbuilt string functions. The definitions for all inbuilt functions in c are written in #include<string.h> library.

Complete String Funtions In C

Return Type	Function Call	Purpose
char *	strcat(str1,str2)	To concatenate or join str2 with str1.
char *	strncat(str1,str2,n)	Concatenate at most n characters of string str2 to string str1, terminate with '\0' and returns str1.
char *	strchr(st,ch)	To find the first occurrence of a character ch in a string st.
char *	strrchr(st,ch)	To find the last occurrence of a character ch in a string st.
char *	strcpy(str2,str1)	To copy a string from str1 to str2.
char *	strncpy(str1,str2,n)	Concatenate at most n characters of string str2 to string str1, terminate with '\0' and return str1.
size_t	strlen(str1)	Returns length of a string str1.
char *	strstr(str1,str2)	Returns a string str2 if it is present in string str1. If not retruns NULL
char *	strpbrk(str1,str2)	To print the string str1 from the first occurrence of any one of the given individual character in str2.
char *	strerror	Return "No error" if a file is found else throw a error message.
char *	strlwr(str)	To convert upper case letters in a string str to lower case letters.
char *	strupr(str)	To convert lower case letters in a string str to upper case letters.
char *	strdup(str)	To duplicate a string str.
char *	strtok(str, chr)	To replace a symbol char with '\n'(new line) in a string str.
int	strcmp(str1,str2)	Compare str1 and str2 and return -1 if str1<str2, 0 if str1 == str2 or +1 if str1>str2.
int	stricmp(str1,str2)	Same as strcmp(str1, str2) but stricmp(str1, str2) is case insensitive.
int	strncmp(str1,str2,n)	Compare at most n characters of string str1 to string str2 and return -1 if str1<str2, 0 if str1==str2 or +1 if str1>str2.
int	strnicmp(str1,str2,str3)	Same as strncmp(str1,str2,n) but strnicmp(str1,str2,str3) is case insensitive
int	strspn(str1,str2)	Return length of prefix of str1 consisting of characters in str2.
int	strcspn(str1,str2)	Return length of perfix of str1 consisting of characters not in str2.
char *	strrev(str1)	To reverse the source string str1.
char *	strset(str1,char)	To replace a string str1 with specified character char.
char *	strnset(str1,char,n)	To replace a string str1 with specified character char up to specified length n.
char *	strswab(str1)	Swapping adjacent characters in a string str1 consecutively.
void *	memcpy(str1,str2,n)	Copy n characters from str2 to str1 and return str1.
void *	memmove(str1,str2,n)	Copy n characters from str2 to str1 , and return str1. It works even if the object overlap.
int	memcmp(str1,str2,n)	Compares the first n characters of str1 with str2 and returns as with strcmp.
void *	memchr(str1,chr,n)	Return a string str1 from a character chr if a character chr present in a string str1 within a length n else return null.
void *	memset(str1,chr,n)	Place character chr into first n characters of a string str1 and return str1.