Add string helpers (actually needed up previous checkin)

string/_info.c

+#include <stdio.h>
+#include <string.h>
+#include "config.h"
+
+/**
+ * string - string helper routines
+ *
+ * This is a grab bag of modules for string comparisons, designed to enhance
+ * the standard string.h.
+ *
+ * Example:
+ *	#include "ccan/string.h"
+ *
+ *	int main(int argc, char *argv[])
+ *	{
+ *		if (argv[1] && streq(argv[1], "--verbose"))
+ *			printf("verbose set\n");
+ *		if (argv[1] && strstarts(argv[1], "--"))
+ *			printf("Some option set\n");
+ *		if (argv[1] && strends(argv[1], "cow-powers"))
+ *			printf("Magic option set\n");
+ *		return 0;
+ *	}
+ */
+int main(int argc, char *argv[])
+{
+	if (argc != 2)
+		return 1;
+
+	if (strcmp(argv[1], "depends") == 0)
+		/* Nothing. */
+		return 0;
+
+	return 1;
+}

string/string.h

+#ifndef CCAN_STRING_H
+#define CCAN_STRING_H
+#include <string.h>
+#include <stdbool.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(str, ""))
+ *		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(str, "foo"))
+ *		printf("String %s begins with 'foo'!\n", str);
+ */
+#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(str, "foo"))
+ *		printf("String %s end with 'foo'!\n", str);
+ */
+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);
+}
+#endif /* CCAN_STRING_H */

string/test/run.c

+#include <stdlib.h>
+#include <stdio.h>
+#include "string/string.h"
+#include "tap.h"
+
+/* FIXME: ccanize */
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
+
+static char *substrings[] = { "far", "bar", "baz", "b", "ba", "z", "ar" };
+
+static char *strdup_rev(const char *s)
+{
+	char *ret = strdup(s);
+	unsigned int i;
+
+	for (i = 0; i < strlen(s); i++)
+		ret[i] = s[strlen(s) - i - 1];
+	return ret;
+}
+
+int main(int argc, char *argv[])
+{
+	unsigned int i, j, n;
+	char *strings[ARRAY_SIZE(substrings) * ARRAY_SIZE(substrings)];
+
+	n = 0;
+	for (i = 0; i < ARRAY_SIZE(substrings); i++) {
+		for (j = 0; j < ARRAY_SIZE(substrings); j++) {
+			strings[n] = malloc(strlen(substrings[i])
+					    + strlen(substrings[j]) + 1);
+			sprintf(strings[n++], "%s%s",
+				substrings[i], substrings[j]);
+		}
+	}
+
+	plan_tests(n * n * 5);
+	for (i = 0; i < n; i++) {
+		for (j = 0; j < n; j++) {
+			unsigned int k, identical = 0;
+			char *reva, *revb;
+
+			/* Find first difference. */
+			for (k = 0; strings[i][k]==strings[j][k]; k++) {
+				if (k == strlen(strings[i])) {
+					identical = 1;
+					break;
+				}
+			}
+
+			if (identical) 
+				ok1(streq(strings[i], strings[j]));
+			else
+				ok1(!streq(strings[i], strings[j]));
+
+			/* Postfix test should be equivalent to prefix
+			 * test on reversed string. */
+			reva = strdup_rev(strings[i]);
+			revb = strdup_rev(strings[j]);
+
+			if (!strings[i][k]) {
+				ok1(strstarts(strings[j], strings[i]));
+				ok1(strends(revb, reva));
+			} else {
+				ok1(!strstarts(strings[j], strings[i]));
+				ok1(!strends(revb, reva));
+			}
+			if (!strings[j][k]) {
+				ok1(strstarts(strings[i], strings[j]));
+				ok1(strends(reva, revb));
+			} else {
+				ok1(!strstarts(strings[i], strings[j]));
+				ok1(!strends(reva, revb));
+			}
+		}
+	}
+	return exit_status();
+}