[monitoring-plugins] Add option to override output for check in lib ...

[GitHub]

    Module: monitoring-plugins
    Branch: master
    Commit: 9980e788509af3203725cdcd15f517ad1ed503fb
    Author: Lorenz Kästle <12514511+RincewindsHat at users.noreply.github.com>
 Committer: GitHub <noreply at github.com>
      Date: Mon Apr  6 12:17:43 2026 +0200
       URL: https://www.monitoring-plugins.org/repositories/monitoring-plugins/commit/?id=9980e788

Add option to override output for check in lib for check_by_ssh (#2230)

The new output functionality was discussed in the context of
check_by_ssh, where it mostly adds more stuff which was seen as
not inherently usefull as a succesful check_by_ssh check
might as well be transparent.

---

 lib/output.c           |  7 +++++++
 lib/output.h           |  4 ++++
 plugins/check_by_ssh.c | 17 +++++++++++++++--
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/lib/output.c b/lib/output.c
index bfd43195..54d505d9 100644
--- a/lib/output.c
+++ b/lib/output.c
@@ -61,6 +61,8 @@ static inline char *fmt_subcheck_perfdata(mp_subcheck check) {
 mp_check mp_check_init(void) {
 	mp_check check = {
 		.evaluation_function = &mp_eval_check_default,
+		.default_output_override = NULL,
+		.default_output_override_content = NULL,
 	};
 	return check;
 }
@@ -283,6 +285,11 @@ char *mp_fmt_output(mp_check check) {
 
 	switch (output_format) {
 	case MP_FORMAT_MULTI_LINE: {
+		if (check.default_output_override != NULL) {
+			result = check.default_output_override(check.default_output_override_content);
+			break;
+		}
+
 		if (check.summary == NULL) {
 			check.summary = get_subcheck_summary(check);
 		}
diff --git a/lib/output.h b/lib/output.h
index c63c8e3f..f5011268 100644
--- a/lib/output.h
+++ b/lib/output.h
@@ -70,6 +70,10 @@ struct mp_check {
 
 	// the evaluation_functions computes the state of check
 	mp_state_enum (*evaluation_function)(mp_check);
+
+	// override for the default output format
+	char *(*default_output_override)(void *);
+	void *default_output_override_content;
 };
 
 mp_check mp_check_init(void);
diff --git a/plugins/check_by_ssh.c b/plugins/check_by_ssh.c
index 7ffa0ded..4d0c8e7d 100644
--- a/plugins/check_by_ssh.c
+++ b/plugins/check_by_ssh.c
@@ -41,6 +41,8 @@ const char *email = "devel at monitoring-plugins.org";
 #	define NP_MAXARGS 1024
 #endif
 
+char *check_by_ssh_output_override(void *remote_output) { return ((char *)remote_output); }
+
 typedef struct {
 	int errorcode;
 	check_by_ssh_config config;
@@ -155,10 +157,21 @@ int main(int argc, char **argv) {
 		xasprintf(&sc_active_check.output, "command stdout:");
 
 		if (child_result.out.lines > skip_stdout) {
+
+			char *remote_command_output = NULL;
 			for (size_t i = skip_stdout; i < child_result.out.lines; i++) {
-				xasprintf(&sc_active_check.output, "%s\n%s", sc_active_check.output,
-						  child_result.out.line[i]);
+				if (i == skip_stdout) {
+					// first iteration
+					xasprintf(&remote_command_output, "%s", child_result.out.line[i]);
+				} else {
+					xasprintf(&remote_command_output, "%s\n%s", remote_command_output,
+							  child_result.out.line[i]);
+				}
 			}
+
+			sc_active_check.output = remote_command_output;
+			overall.default_output_override_content = remote_command_output;
+			overall.default_output_override = check_by_ssh_output_override;
 		} else {
 			xasprintf(&sc_active_check.output, "remote command '%s' returned status %d",
 					  config.remotecmd, child_result.cmd_error_code);