NAME
memchr — find byte
in memory
SYNOPSIS
#include
<string.h>
void *memchr(const void *s, int c, size_t n);
DESCRIPTION
[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2024 defers to the ISO C standard.
The memchr () function shall locate
the first occurrence of
c (converted to an
unsigned char) in the initial
n bytes (each
interpreted as unsigned char) pointed to by
s.
The implementation shall behave as if it reads the bytes sequentially and stops as soon as a matching byte is found.
[CX] The memchr ()
function shall not change the setting of errno on valid
input.
RETURN VALUE
The memchr () function shall return a
pointer to the located byte, or a null pointer if the byte is not found.
ERRORS
No errors are defined.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
XBD <string.h>
CHANGE HISTORY
First released in Issue 1. Derived from Issue 1 of the SVID.
Issue 7
POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0374 [110] is applied.
Issue 8
Austin Group Defect 448 is applied, adding a requirement that
memchr () does not change the setting of
errno on valid input.
Austin Group Defect 1302 is applied, aligning this function with the ISO/IEC 9899:2018 standard.