Format options help into indented paragraphs

argparse/argparse.c

@@ -368,7 +368,30 @@ argparse_usage(struct argparse *self)
             fputc('\n', stdout);
             pad = usage_opts_width;
         }
-        fprintf(stdout, "%*s%s\n", pad + 2, "", options->help);
+        if (options->help != NULL && strlen(options->help) > 0) {
+            char *str = strdup(options->help);
+            char *token = strtok(str, " ");
+            fprintf(stdout, "%*s%s ", pad + 2, "", token);
+            int count = strlen(token);
+            int dangling = 1;
+            while ((token = strtok(NULL, " ")) != NULL) {
+                if (count == 0) {
+                    fprintf(stdout, "%*s", (int)pos + pad + 2, "");
+                    dangling = 1;
+                }
+                printf("%s ", token);
+                count += strlen(token);
+                if (count > 30) {
+                    count = 0;
+                    fprintf(stdout, "\n");
+                    dangling = 0;
+                }
+            }
+            if (dangling) fprintf(stdout, "\n"); 
+        } else {
+            fprintf(stdout, "\n");
+        }
+        
     }
 
     // print epilog

examples/main.c

@@ -198,7 +198,7 @@ int main(int argc, char *argv[]) {
                   "Pin runners using processor affinity.", NULL, 0, 0),
       OPT_BOOLEAN('d', "dry-run", &dry_run, 
                   "Dry run. Read the parameter file, allocates memory but "
-                  "does not read the particles from ICs.\t\nExits before the "
+                  "does not read the particles from ICs. Exits before the "
                   "start of time integration. Checks the validity of "
                   "parameters and IC files as well as memory limits.",
                   NULL, 0, 0),