This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding Linux
manual page for details of Linux behavior), or the interface may not be
implemented on Linux.
memchr — find byte in memory
void *memchr(const void *s, int c, size_t n);
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.1‐2017 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.
Implementations shall behave as if they read the memory byte by
byte from the beginning of the bytes pointed to by s and stop at the
first occurrence of c (if it is found in the initial n
The memchr() function shall return a pointer to the located byte, or a
null pointer if the byte is not found.
No errors are defined.
The following sections are informative.
The Base Definitions volume of POSIX.1‐2017,
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1-2017, Standard for Information Technology -- Portable Operating
System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018
Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html .
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