Add a strtobool function matching semantics of existing in kernel equivalents

This is a rename of the usr_strtobool proposal, which was a renamed, relocated and fixed version of previous kstrtobool RFC Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Add a strtobool function matching semantics of existing in kernel equivalents
This is a rename of the usr_strtobool proposal, which was a renamed, relocated and fixed version of previous kstrtobool RFC Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Jonathan Cameron · Rusty Russell
1 parent 6845756b29
Showing 2 changed files with 30 additions and 0 deletions Side-by-side Diff
include/linux/string.h
lib/string.c
@@ -123,6 +123,7 @@
 extern void argv_free(char **argv);
  
 extern bool sysfs_streq(const char *s1, const char *s2);
+extern int strtobool(const char *s, bool *res);
  
 #ifdef CONFIG_BINARY_PRINTF
 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
@@ -535,6 +535,35 @@
 }
 EXPORT_SYMBOL(sysfs_streq);
  
+/**
+ * strtobool - convert common user inputs into boolean values
+ * @s: input string
+ * @res: result
+ *
+ * This routine returns 0 iff the first character is one of 'Yy1Nn0'.
+ * Otherwise it will return -EINVAL.  Value pointed to by res is
+ * updated upon finding a match.
+ */
+int strtobool(const char *s, bool *res)
+{
+	switch (s[0]) {
+	case 'y':
+	case 'Y':
+	case '1':
+		*res = true;
+		break;
+	case 'n':
+	case 'N':
+	case '0':
+		*res = false;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(strtobool);
+
 #ifndef __HAVE_ARCH_MEMSET
 /**
  * memset - Fill a region of memory with the given value
...	...	@@ -123,6 +123,7 @@
123	123	extern void argv_free(char **argv);
124	124
125	125	extern bool sysfs_streq(const char s1, const char s2);
	126	+extern int strtobool(const char s, bool res);
126	127
127	128	#ifdef CONFIG_BINARY_PRINTF
128	129	int vbin_printf(u32 bin_buf, size_t size, const char fmt, va_list args);
...	...	@@ -535,6 +535,35 @@
535	535	}
536	536	EXPORT_SYMBOL(sysfs_streq);
537	537
	538	+/**
	539	+ * strtobool - convert common user inputs into boolean values
	540	+ * @s: input string
	541	+ * @res: result
	542	+ *
	543	+ * This routine returns 0 iff the first character is one of 'Yy1Nn0'.
	544	+ * Otherwise it will return -EINVAL. Value pointed to by res is
	545	+ * updated upon finding a match.
	546	+ */
	547	+int strtobool(const char s, bool res)
	548	+{
	549	+ switch (s[0]) {
	550	+ case 'y':
	551	+ case 'Y':
	552	+ case '1':
	553	+ *res = true;
	554	+ break;
	555	+ case 'n':
	556	+ case 'N':
	557	+ case '0':
	558	+ *res = false;
	559	+ break;
	560	+ default:
	561	+ return -EINVAL;
	562	+ }
	563	+ return 0;
	564	+}
	565	+EXPORT_SYMBOL(strtobool);
	566	+
538	567	#ifndef __HAVE_ARCH_MEMSET
539	568	/**
540	569	* memset - Fill a region of memory with the given value