1 files changed, 120 insertions, 0 deletions
diff --git a/ccan/str/str.h b/ccan/str/str.h
new file mode 100644
index 00000000..89668c68
--- /dev/null
+++ b/ccan/str/str.h
@@ -0,0 +1,120 @@
+/* CC0 (Public domain) - see LICENSE file for details */
+#ifndef CCAN_STR_H
+#define CCAN_STR_H
+#include "config.h"
+#include <string.h>
+#include <stdbool.h>
+#include <limits.h>
+#include <ctype.h>
+
+/**
+ * streq - Are two strings equal?
+ * @a: first string
+ * @b: first string
+ *
+ * This macro is arguably more readable than "!strcmp(a, b)".
+ *
+ * Example:
+ *	if (streq(somestring, ""))
+ *		printf("String is empty!\n");
+ */
+#define streq(a,b) (strcmp((a),(b)) == 0)
+
+/**
+ * strstarts - Does this string start with this prefix?
+ * @str: string to test
+ * @prefix: prefix to look for at start of str
+ *
+ * Example:
+ *	if (strstarts(somestring, "foo"))
+ *		printf("String %s begins with 'foo'!\n", somestring);
+ */
+#define strstarts(str,prefix) (strncmp((str),(prefix),strlen(prefix)) == 0)
+
+/**
+ * strends - Does this string end with this postfix?
+ * @str: string to test
+ * @postfix: postfix to look for at end of str
+ *
+ * Example:
+ *	if (strends(somestring, "foo"))
+ *		printf("String %s end with 'foo'!\n", somestring);
+ */
+static inline bool strends(const char *str, const char *postfix)
+{
+	if (strlen(str) < strlen(postfix))
+		return false;
+
+	return streq(str + strlen(str) - strlen(postfix), postfix);
+}
+
+/**
+ * stringify - Turn expression into a string literal
+ * @expr: any C expression
+ *
+ * Example:
+ *	#define PRINT_COND_IF_FALSE(cond) \
+ *		((cond) || printf("%s is false!", stringify(cond)))
+ */
+#define stringify(expr)		stringify_1(expr)
+/* Double-indirection required to stringify expansions */
+#define stringify_1(expr)	#expr
+
+/**
+ * strcount - Count number of (non-overlapping) occurrences of a substring.
+ * @haystack: a C string
+ * @needle: a substring
+ *
+ * Example:
+ *      assert(strcount("aaa aaa", "a") == 6);
+ *      assert(strcount("aaa aaa", "ab") == 0);
+ *      assert(strcount("aaa aaa", "aa") == 2);
+ */
+size_t strcount(const char *haystack, const char *needle);
+
+/**
+ * STR_MAX_CHARS - Maximum possible size of numeric string for this type.
+ * @type_or_expr: a pointer or integer type or expression.
+ *
+ * This provides enough space for a nul-terminated string which represents the
+ * largest possible value for the type or expression.
+ *
+ * Note: The implementation adds extra space so hex values or negative
+ * values will fit (eg. sprintf(... "%p"). )
+ *
+ * Example:
+ *	char str[STR_MAX_CHARS(int)];
+ *
+ *	sprintf(str, "%i", 7);
+ */
+#define STR_MAX_CHARS(type_or_expr)				\
+	((sizeof(type_or_expr) * CHAR_BIT + 8) / 9 * 3 + 2	\
+	 + STR_MAX_CHARS_TCHECK_(type_or_expr))
+
+#if HAVE_TYPEOF
+/* Only a simple type can have 0 assigned, so test that. */
+#define STR_MAX_CHARS_TCHECK_(type_or_expr)		\
+	({ typeof(type_or_expr) x = 0; (void)x; 0; })
+#else
+#define STR_MAX_CHARS_TCHECK_(type_or_expr) 0
+#endif
+
+/* These checks force things out of line, hence they are under DEBUG. */
+#ifdef CCAN_STR_DEBUG
+#if HAVE_TYPEOF
+/* With GNU magic, we can make const-respecting standard string functions. */
+#undef strstr
+#undef strchr
+#undef strrchr
+
+/* + 0 is needed to decay array into pointer. */
+#define strstr(haystack, needle)					\
+	((typeof((haystack) + 0))str_strstr((haystack), (needle)))
+#define strchr(haystack, c)					\
+	((typeof((haystack) + 0))str_strchr((haystack), (c)))
+#define strrchr(haystack, c)					\
+	((typeof((haystack) + 0))str_strrchr((haystack), (c)))
+#endif
+#endif /* CCAN_STR_DEBUG */
+
+#endif /* CCAN_STR_H */