From: Florian Forster <octo@leeloo.lan.home.verplant.org>
Date: Sat, 20 Dec 2008 15:54:32 +0000 (+0100)
Subject: src/utils_subst.[ch]: Implement `subst_string'.
X-Git-Tag: collectd-4.6.0~122
X-Git-Url: https://git.octo.it/?p=collectd.git;a=commitdiff_plain;h=088d5c6d5a5ea3457cd6a4eafff40f5c780c3692

src/utils_subst.[ch]: Implement `subst_string'.

Works like `subst', but instead of specifying start and end offsets you
specify `needle', the string that is to be replaced. If `needle' is found
in `string' (using strstr(3)), the offset is calculated and `subst' is
called with the determined parameters.
---

diff --git a/src/utils_subst.c b/src/utils_subst.c
index 05dc8441..3c9fe5a2 100644
--- a/src/utils_subst.c
+++ b/src/utils_subst.c
@@ -78,5 +78,66 @@ char *asubst (const char *string, int off1, int off2, const char *replacement)
 	return ret;
 } /* asubst */
 
+char *subst_string (char *buf, size_t buflen, const char *string,
+		const char *needle, const char *replacement)
+{
+	char *temp;
+	size_t needle_len;
+	size_t i;
+
+	if ((buf == NULL) || (string == NULL)
+			|| (needle == NULL) || (replacement == NULL))
+		return (NULL);
+
+	temp = (char *) malloc (buflen);
+	if (temp == NULL)
+	{
+		ERROR ("subst_string: malloc failed.");
+		return (NULL);
+	}
+
+	needle_len = strlen (needle);
+	strncpy (buf, string, buflen);
+
+	/* Limit the loop to prevent endless loops. */
+	for (i = 0; i < buflen; i++)
+	{
+		char *begin_ptr;
+		size_t begin;
+
+		/* Find `needle' in `buf'. */
+		begin_ptr = strstr (buf, needle);
+		if (begin_ptr == NULL)
+			break;
+
+		/* Calculate the start offset. */
+		begin = begin_ptr - buf;
+
+		/* Substitute the region using `subst'. The result is stored in
+		 * `temp'. */
+		begin_ptr = subst (temp, buflen, buf,
+				begin, begin + needle_len,
+				replacement);
+		if (begin_ptr == NULL)
+		{
+			WARNING ("subst_string: subst failed.");
+			break;
+		}
+
+		/* Copy the new string in `temp' to `buf' for the next round. */
+		strncpy (buf, temp, buflen);
+	}
+
+	if (i >= 100)
+	{
+		WARNING ("subst_string: Loop exited after %zu iterations: "
+				"string = %s; needle = %s; replacement = %s;",
+				i, string, needle, replacement);
+	}
+
+	sfree (temp);
+	return (buf);
+} /* char *subst_string */
+
 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */
 
diff --git a/src/utils_subst.h b/src/utils_subst.h
index bba33af4..4387b85d 100644
--- a/src/utils_subst.h
+++ b/src/utils_subst.h
@@ -75,6 +75,25 @@ char *subst (char *buf, size_t buflen, const char *string, int off1, int off2,
  */
 char *asubst (const char *string, int off1, int off2, const char *replacement);
 
+/*
+ * subst_string:
+ *
+ * Works like `subst', but instead of specifying start and end offsets you
+ * specify `needle', the string that is to be replaced. If `needle' is found
+ * in `string' (using strstr(3)), the offset is calculated and `subst' is
+ * called with the determined parameters.
+ *
+ * If the substring is not found, no error will be indicated and
+ * `subst_string' works mostly like `strncpy'.
+ *
+ * If the substring appears multiple times, all appearances will be replaced.
+ * If the substring has been found `buflen' times, an endless loop is assumed
+ * and the loop is broken. A warning is printed and the function returns
+ * success.
+ */
+char *subst_string (char *buf, size_t buflen, const char *string,
+		const char *needle, const char *replacement);
+
 #endif /* UTILS_SUBST_H */
 
 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */