From: Yury Norov <yury.norov@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
"David S . Miller" <davem@davemloft.net>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Amritha Nambiar <amritha.nambiar@intel.com>,
Willem de Bruijn <willemb@google.com>,
Kees Cook <keescook@chromium.org>,
Matthew Wilcox <willy@infradead.org>,
"Tobin C . Harding" <tobin@kernel.org>,
Will Deacon <will.deacon@arm.com>,
Miklos Szeredi <mszeredi@redhat.com>,
Vineet Gupta <vineet.gupta1@synopsys.com>,
Chris Wilson <chris@chris-wilson.co.uk>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
linux-kernel@vger.kernel.org
Cc: Yury Norov <yury.norov@gmail.com>, Jens Axboe <axboe@kernel.dk>,
Steffen Klassert <steffen.klassert@secunet.com>
Subject: [PATCH 1/7] lib/string: add strnchrnul()
Date: Sun, 8 Sep 2019 20:30:15 -0700 [thread overview]
Message-ID: <20190909033021.11600-2-yury.norov@gmail.com> (raw)
In-Reply-To: <20190909033021.11600-1-yury.norov@gmail.com>
New function works like strchrnul() with a length limited strings.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
include/linux/string.h | 1 +
lib/string.c | 17 +++++++++++++++++
2 files changed, 18 insertions(+)
diff --git a/include/linux/string.h b/include/linux/string.h
index 3cf684db4bc6b..cf8f47efeb051 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -107,6 +107,7 @@ extern char * strchr(const char *,int);
#ifndef __HAVE_ARCH_STRCHRNUL
extern char * strchrnul(const char *,int);
#endif
+extern char * strnchrnul(const char *, size_t, int);
#ifndef __HAVE_ARCH_STRNCHR
extern char * strnchr(const char *, size_t, int);
#endif
diff --git a/lib/string.c b/lib/string.c
index cd7a10c192109..75b10363e61f0 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -434,6 +434,23 @@ char *strchrnul(const char *s, int c)
EXPORT_SYMBOL(strchrnul);
#endif
+/**
+ * strnchrnul - Find and return a character in a length limited string,
+ * or end of string
+ * @s: The string to be searched
+ * @count: The number of characters to be searched
+ * @c: The character to search for
+ *
+ * Returns pointer to the first occurrence of 'c' in s. If c is not found,
+ * then return a pointer to the last character of the string.
+ */
+char *strnchrnul(const char *s, size_t count, int c)
+{
+ while (count-- && *s && *s != (char)c)
+ s++;
+ return (char *)s;
+}
+
#ifndef __HAVE_ARCH_STRRCHR
/**
* strrchr - Find the last occurrence of a character in a string
--
2.20.1
next prev parent reply other threads:[~2019-09-09 3:33 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-09 3:30 [PATCH v4 0/7] lib: rework bitmap_parse Yury Norov
2019-09-09 3:30 ` Yury Norov [this message]
2019-09-09 3:30 ` [PATCH 2/7] bitops: more BITS_TO_* macros Yury Norov
2019-09-09 3:30 ` [PATCH 3/7] lib: add test for bitmap_parse() Yury Norov
2019-09-09 3:30 ` [PATCH 4/7] lib: make bitmap_parse_user a wrapper on bitmap_parse Yury Norov
2019-09-09 3:30 ` [PATCH 5/7] lib: rework bitmap_parse() Yury Norov
2019-09-09 10:06 ` Andy Shevchenko
2019-09-09 3:30 ` [PATCH 6/7] lib: new testcases for bitmap_parse{_user} Yury Norov
2019-09-09 3:30 ` [PATCH 7/7] cpumask: don't calculate length of the input string Yury Norov
-- strict thread matches above, loose matches on Subject: below --
2020-01-02 4:30 [PATCH v5 0/7] lib: rework bitmap_parse Yury Norov
2020-01-02 4:30 ` [PATCH 1/7] lib/string: add strnchrnul() Yury Norov
2019-07-21 21:27 [PATCH v3 0/7] lib: rework bitmap_parse Yury Norov
2019-07-21 21:27 ` [PATCH 1/7] lib/string: add strnchrnul() Yury Norov
2019-05-01 1:06 [PATCH 0/7] lib: rework bitmap_parse Yury Norov
2019-05-01 1:06 ` [PATCH 1/7] lib/string: add strnchrnul() Yury Norov
2019-05-08 8:47 ` Andy Shevchenko
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