[RFC PATCH V2 1/2] mkfs.f2fs: add helper strtrim() to trim string's space

[Sheng Yong <shengyong1@huawei.com>]

Add a helper function strtrim() to trim space both at the beginning and end
of a string.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
---
 include/f2fs_fs.h |  1 +
 lib/libf2fs.c     | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h
index 359deec..e85b2d0 100644
--- a/include/f2fs_fs.h
+++ b/include/f2fs_fs.h
@@ -768,6 +768,7 @@ enum {
 
 extern void ASCIIToUNICODE(u_int16_t *, u_int8_t *);
 extern int log_base_2(u_int32_t);
+extern void strtrim(char **str);
 extern unsigned int addrs_per_inode(struct f2fs_inode *);
 
 extern int get_bits_in_byte(unsigned char n);
diff --git a/lib/libf2fs.c b/lib/libf2fs.c
index 83d1296..e901289 100644
--- a/lib/libf2fs.c
+++ b/lib/libf2fs.c
@@ -48,6 +48,30 @@ int log_base_2(u_int32_t num)
 	return ret;
 }
 
+void strtrim(char **str)
+{
+	int len = strlen(*str);
+	char *head = *str;
+	char *tail = *str + len - 1;
+
+	while (head != tail) {
+		if (*head == ' ')
+			head++;
+		else {
+			*str = head;
+			break;
+		}
+	}
+
+	while (tail != head) {
+		if (*tail == ' ') {
+			*tail = '\0';
+			tail--;
+		} else
+			break;
+	}
+}
+
 /*
  * f2fs bit operations
  */
-- 
1.9.1


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