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The memchr () function in C

The function void * memchr (const void * str, int c, size_t n) looks for the first occurrence of the character c (an unsigned char) in the first n bytes of the string pointed to by parameter str.

Declaring the function memchr () in C

Below is the declaration for memchr () in C:

 void * memchr ( const void * str , int c , size_t n )

Parameters

str - This is the pointer to the memory block where the search is performed.

c - This is the value to be transmitted in the form of an int, but the function performs a byte search using the unsigned char conversion of this value.

n - This is the number of bytes to be analyzed.

Returns the value

This function returns a pointer to the connected byte or NULL if the character does not appear in the given memory area.

For example

The following program C illustrates the usage of memchr () in C:

 #include #include int main () { char * pch ; char str [] = "Hoc C co ban va nang cao tai QTM" ; pch = ( char *) memchr ( str , 'v' , strlen ( str )); if ( pch != NULL ) printf ( "Tim thay 'v' tai vi tri %d.n" , pch - str + 1 ); else printf ( "Khong tim thay ky tu 'v'.n" ); return 0 ; }

Compiling and running the above C program will result:

The memchr () function in C Picture 1

According to Tutorialspoint

Last lesson: string.h in C

Next lesson: Function memcmp () in C

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