[monitoring-plugins] Make multiline output look better

[Lorenz Kästle]

 Module: monitoring-plugins
 Branch: master
 Commit: bb4ce15997a3023c5c4f2bb434b37699797272da
 Author: Lorenz Kästle <12514511+rincewinds...@users.noreply.github.com>
   Date: Sun Jul  6 22:47:01 2025 +0200
    URL: 
https://www.monitoring-plugins.org/repositories/monitoring-plugins/commit/?id=bb4ce159

Make multiline output look better

---

 lib/output.c | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/lib/output.c b/lib/output.c
index 61fbf832..fbde490e 100644
--- a/lib/output.c
+++ b/lib/output.c
@@ -332,7 +332,37 @@ static inline char *fmt_subcheck_output(mp_output_format 
output_format, mp_subch
        mp_subcheck_list *subchecks = NULL;
 
        switch (output_format) {
-       case MP_FORMAT_MULTI_LINE:
+       case MP_FORMAT_MULTI_LINE: {
+               char *tmp_string = NULL;
+               if ((tmp_string = strchr(check.output, '\n')) != NULL) {
+                       // This is a multiline string, put the correct 
indentation in before proceeding
+                       char *intermediate_string = "";
+                       bool have_residual_chars = false;
+
+                       while (tmp_string != NULL) {
+                               *tmp_string = '\0';
+                               xasprintf(&intermediate_string, "%s%s\n%s", 
intermediate_string,check.output, generate_indentation_string(indentation+1)); 
// one more indentation to make it look better
+
+                               if (*(tmp_string + 1) != '\0') {
+                                       check.output = tmp_string + 1;
+                                       have_residual_chars = true;
+                               } else {
+                                       // Null after the \n, so this is the end
+                                       have_residual_chars = false;
+                                       break;
+                               }
+
+                               tmp_string = strchr(check.output, '\n');
+                       }
+
+                       // add the rest (if any)
+                       if (have_residual_chars) {
+                               char *tmp = check.output;
+                               xasprintf(&check.output, "%s\n%s%s", 
intermediate_string, generate_indentation_string(indentation+1), tmp);
+                       } else {
+                               check.output = intermediate_string;
+                       }
+               }
                asprintf(&result, "%s\\_[%s] - %s", 
generate_indentation_string(indentation), 
state_text(mp_compute_subcheck_state(check)),
                                 check.output);
 
@@ -343,6 +373,7 @@ static inline char *fmt_subcheck_output(mp_output_format 
output_format, mp_subch
                        subchecks = subchecks->next;
                }
                return result;
+       }
        default:
                die(STATE_UNKNOWN, "Invalid format");
        }