memchr(3) - Linux manual page (original) (raw)
memchr(3) Library Functions Manual memchr(3)
NAME top
memchr, memrchr, rawmemchr - scan memory for a characterLIBRARY top
Standard C library (_libc_, _-lc_)SYNOPSIS top
**#include <string.h>**
**void *memchr(const void** _s_**[.**_n_**], int** _c_**, size_t** _n_**);**
**void *memrchr(const void** _s_**[.**_n_**], int** _c_**, size_t** _n_**);**
**[[deprecated]] void *rawmemchr(const void ***_s_**, int** _c_**);**Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
**memrchr**(), **rawmemchr**():
_GNU_SOURCEDESCRIPTION top
The **memchr**() function scans the initial _n_ bytes of the memory area
pointed to by _s_ for the first instance of _c_. Both _c_ and the bytes
of the memory area pointed to by _s_ are interpreted as _unsigned_
_char_.
The **memrchr**() function is like the **memchr**() function, except that
it searches backward from the end of the _n_ bytes pointed to by _s_
instead of forward from the beginning.
The **rawmemchr**() function is similar to **memchr**(), but it assumes
(i.e., the programmer knows for certain) that an instance of _c_
lies somewhere in the memory area starting at the location pointed
to by _s_. If an instance of _c_ is not found, the behavior is
undefined. Use either [strlen(3)](../man3/strlen.3.html) or [memchr(3)](../man3/memchr.3.html) instead.RETURN VALUE top
The **memchr**() and **memrchr**() functions return a pointer to the
matching byte or NULL if the character does not occur in the given
memory area.
The **rawmemchr**() function returns a pointer to the matching byte.ATTRIBUTES top
For an explanation of the terms used in this section, see
[attributes(7)](../man7/attributes.7.html).
┌──────────────────────────────────────┬───────────────┬─────────┐
│ **Interface** │ **Attribute** │ **Value** │
├──────────────────────────────────────┼───────────────┼─────────┤
│ **memchr**(), **memrchr**(), **rawmemchr**() │ Thread safety │ MT-Safe │
└──────────────────────────────────────┴───────────────┴─────────┘STANDARDS top
**memchr**()
C11, POSIX.1-2008.
**memrchr**()
**rawmemchr**()
GNU.HISTORY top
**memchr**()
POSIX.1-2001, C89, SVr4, 4.3BSD.
**memrchr**()
glibc 2.2.
**rawmemchr**()
glibc 2.1.SEE ALSO top
[bstring(3)](../man3/bstring.3.html), [ffs(3)](../man3/ffs.3.html), [memmem(3)](../man3/memmem.3.html), [strchr(3)](../man3/strchr.3.html), [strpbrk(3)](../man3/strpbrk.3.html), [strrchr(3)](../man3/strrchr.3.html),
[strsep(3)](../man3/strsep.3.html), [strspn(3)](../man3/strspn.3.html), [strstr(3)](../man3/strstr.3.html), [wmemchr(3)](../man3/wmemchr.3.html)COLOPHON top
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man-pages@man7.orgLinux man-pages 6.10 2024-07-23 memchr(3)
Pages that refer to this page:bstring(3), ffs(3), memchr(3), strchr(3), strpbrk(3), strsep(3), strspn(3), strstr(3), strtok(3), wmemchr(3), signal-safety(7)