linux-kernel - [RFC PATCH 17/30] lib/string.c: strsep_no

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Message-ID: <20220830214919.53220-18-surenb@google.com>
Date:   Tue, 30 Aug 2022 14:49:06 -0700
From:   Suren Baghdasaryan <surenb@...gle.com>
To:     akpm@...ux-foundation.org
Cc:     kent.overstreet@...ux.dev, mhocko@...e.com, vbabka@...e.cz,
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Subject: [RFC PATCH 17/30] lib/string.c: strsep_no_empty()

From: Kent Overstreet <kent.overstreet@...ux.dev>

This adds a new helper which is like strsep, except that it skips empty
tokens.

Signed-off-by: Kent Overstreet <kent.overstreet@...ux.dev>
---
 include/linux/string.h |  1 +
 lib/string.c           | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/include/linux/string.h b/include/linux/string.h
index 61ec7e4f6311..b950ac9cfa56 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -96,6 +96,7 @@ extern char * strpbrk(const char *,const char *);
 #ifndef __HAVE_ARCH_STRSEP
 extern char * strsep(char **,const char *);
 #endif
+extern char *strsep_no_empty(char **, const char *);
 #ifndef __HAVE_ARCH_STRSPN
 extern __kernel_size_t strspn(const char *,const char *);
 #endif
diff --git a/lib/string.c b/lib/string.c
index 6f334420f687..6939f5b751f2 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -596,6 +596,25 @@ char *strsep(char **s, const char *ct)
 EXPORT_SYMBOL(strsep);
 #endif
 
+/**
+ * strsep_no_empt - Split a string into tokens, but don't return empty tokens
+ * @s: The string to be searched
+ * @ct: The characters to search for
+ *
+ * strsep() updates @s to point after the token, ready for the next call.
+ */
+char *strsep_no_empty(char **s, const char *ct)
+{
+	char *ret;
+
+	do {
+		ret = strsep(s, ct);
+	} while (ret && !*ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(strsep_no_empty);
+
 #ifndef __HAVE_ARCH_MEMSET
 /**
  * memset - Fill a region of memory with the given value
-- 
2.37.2.672.g94769d06f0-goog