diff --git a/run-command.c b/run-command.c
index 0b432cc..65ecbe3 100644
--- a/run-command.c
+++ b/run-command.c
@@ -833,3 +833,19 @@
 
 	return ret;
 }
+
+int capture_command(struct child_process *cmd, struct strbuf *buf, size_t hint)
+{
+	cmd->out = -1;
+	if (start_command(cmd) < 0)
+		return -1;
+
+	if (strbuf_read(buf, cmd->out, hint) < 0) {
+		close(cmd->out);
+		finish_command(cmd); /* throw away exit code */
+		return -1;
+	}
+
+	close(cmd->out);
+	return finish_command(cmd);
+}
diff --git a/run-command.h b/run-command.h
index d6868dc..263b966 100644
--- a/run-command.h
+++ b/run-command.h
@@ -71,6 +71,19 @@
  */
 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
 
+/**
+ * Execute the given command, capturing its stdout in the given strbuf.
+ * Returns -1 if starting the command fails or reading fails, and otherwise
+ * returns the exit code of the command. The output collected in the
+ * buffer is kept even if the command returns a non-zero exit. The hint field
+ * gives a starting size for the strbuf allocation.
+ *
+ * The fields of "cmd" should be set up as they would for a normal run_command
+ * invocation. But note that there is no need to set cmd->out; the function
+ * sets it up for the caller.
+ */
+int capture_command(struct child_process *cmd, struct strbuf *buf, size_t hint);
+
 /*
  * The purpose of the following functions is to feed a pipe by running
  * a function asynchronously and providing output that the caller reads.