[groff] 62/80: [grn]: Align with modern groff conventions.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 7ba2e6df809b42ecf8be325aa018f271f0d0a3fe
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Fri Nov 29 00:49:41 2024 -0600

    [grn]: Align with modern groff conventions.
    
    * src/preproc/grn/main.cpp (usage): If asked for `--help`, summarize
      command purpose in message.
    
      (main): Use standard symbol `EXIT_SUCCESS` instead of `0` literal.
      Recast wording of diagnostic message.
---
 ChangeLog                |  9 +++++++++
 src/preproc/grn/main.cpp | 14 +++++++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 3c41a87ff..9a082f793 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2024-11-29  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       [grn]: Align with modern groff conventions.
+
+       * src/preproc/grn/main.cpp (usage): If asked for `--help`,
+       summarize command purpose in message.
+       (main): Use standard symbol `EXIT_SUCCESS` instead of `0`
+       literal.  Recast wording of diagnostic message.
+
 2024-11-29  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        [grn]: Fix command-line option handling.
diff --git a/src/preproc/grn/main.cpp b/src/preproc/grn/main.cpp
index d05b50dac..93fb6cd7b 100644
--- a/src/preproc/grn/main.cpp
+++ b/src/preproc/grn/main.cpp
@@ -83,9 +83,9 @@
 #include <ctype.h> // isdigit(), isupper(), tolower()
 #include <errno.h>
 #include <locale.h> // setlocale()
-#include <stdio.h> // FILE, fclose(), fgets(), fopen(), stderr, stdin,
-                  // stdout
-#include <stdlib.h> // free(), malloc()
+#include <stdio.h> // FILE, fclose(), fgets(), fopen(), fprintf(),
+                  // fputs(), printf(), stderr, stdin, stdout
+#include <stdlib.h> // exit(), EXIT_SUCCESS, free(), malloc()
 #include <string.h> // strchr(), strcmp(), strcpy(), strerror(),
                    // strlen()
 
@@ -273,6 +273,10 @@ usage(FILE *stream)
          "usage: %s {-v | --version}\n"
          "usage: %s --help\n",
          program_name, program_name, program_name);
+  if (stdout == stream)
+    fputs("\n"
+"Preprocess troff(1) input to incorporate gremlin image files.  See\n"
+"the grn(1) manual page.\n", stream);
 }
 
 
@@ -357,7 +361,7 @@ main(int argc,
        if (strcmp(*argv,"--version")==0) {
       case 'v':
          printf("GNU grn (groff) version %s\n", Version_string);
-         exit(0);
+         exit(EXIT_SUCCESS);
          break;
        }
        if (strcmp(*argv,"--help")==0) {
@@ -368,7 +372,7 @@ main(int argc,
        }
        // fallthrough
       default:
-       error("unknown switch: %1", c);
+       error("unrecognized command-line option '%1'", c);
        usage(stderr);
        exit(2);
       }