memchr

Locate byte in byte string

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Contents

Interface
Description
Return Values
See Also
Standards
Page Comments

Interface

#include <string.h>void  memchr (const void *b, int c, size_t len)

Description

The memchr function locates the first occurrence of c (converted to an unsigned char) in string b.

Example:

Example - Locate byte in byte string

Workings

#include <stdio.h>
#include <string.h>
int main()
{
  // define a table of values
  unsigned char values[10] = {0, 2, 4, 6, 8, 1, 3, 5, 7, 9};
  // look for the value 3 and display search result
  unsigned char *pos = (unsigned char *)memchr(values, 3, 10);
  if (pos)
    printf("Value 3 found at position %d.\n", pos - values);
  else
    printf("Value 3 not found.\n");
  return 0;
}

Solution

Output:

Value 3 found at position 6.

Return Values

The memchr function returns a pointer to the byte located, or NULL if no such byte exists within len bytes.

Standards

The memchr function conforms to ISO/IEC 9899:1990 ("ISO C90").