diff mbox series

[5/9] libtracefs: Add API tracefs_list_dup()

Message ID 20210810204818.880714-6-rostedt@goodmis.org
State New
Headers show
Series libtracefs: APIs to read a trace event hist file | expand

Commit Message

Steven Rostedt Aug. 10, 2021, 8:48 p.m. UTC 
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

Add an API tracefs_list_dup() that will duplicate an existing list.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/tracefs.h   |  1 +
 src/tracefs-utils.c | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+)
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Patch

diff --git a/include/tracefs.h b/include/tracefs.h
index f1e4ffa0d65f..6fb66c44afc7 100644
--- a/include/tracefs.h
+++ b/include/tracefs.h
@@ -67,6 +67,7 @@  void tracefs_list_free(char **list);
 char **tracefs_list_add(char **list, const char *string);
 int tracefs_list_size(char **list);
 int tracefs_list_pop(char **list);
+char **tracefs_list_dup(char **list);
 
 /**
  * tracefs_trace_on_get_fd - Get a file descriptor of "tracing_on" in given instance
diff --git a/src/tracefs-utils.c b/src/tracefs-utils.c
index 63bb413298fe..8c92d6c54ab1 100644
--- a/src/tracefs-utils.c
+++ b/src/tracefs-utils.c
@@ -489,3 +489,29 @@  int tracefs_list_size(char **list)
 	list--;
 	return (int)*(unsigned long *)list;
 }
+
+/**
+ * tracefs_list_dup - create a duplicate list
+ * @list: The list to duplicate
+ *
+ * Allocates a new list that can be modified and freed separately.
+ *
+ * Returns a new allocated list that must be freed with
+ * tracefs_list_free(), or NULL on error.
+ */
+char **tracefs_list_dup(char **list)
+{
+	char **new = NULL;
+	char **tmp;
+	int i;
+
+	for (i = 0; list[i]; i++) {
+		tmp = tracefs_list_add(new, list[i]);
+		if (!tmp) {
+			free(new);
+			return NULL;
+		}
+		new = tmp;
+	}
+	return new;
+}