From 2fa1ce2f554b4f0c492b8b2b268870bb5511f053 Mon Sep 17 00:00:00 2001
From: Thomas Bernard <miniupnp@free.fr>
Date: Sat, 7 Mar 2020 16:28:27 +0100
Subject: [PATCH] tiffset: print usage on stdout when -h is used

also use EXIT_FAILURE / EXIT_SUCCESS
see #17
---
 tools/tiffset.c | 43 ++++++++++++++++++++++++++++---------------
 1 file changed, 28 insertions(+), 15 deletions(-)

diff --git a/tools/tiffset.c b/tools/tiffset.c
index 3725aa61..75cf45c0 100644
--- a/tools/tiffset.c
+++ b/tools/tiffset.c
@@ -39,7 +39,14 @@
 # include "libport.h"
 #endif
 
-static char* usageMsg[] = {
+#ifndef EXIT_SUCCESS
+#define EXIT_SUCCESS 0
+#endif
+#ifndef EXIT_FAILURE
+#define EXIT_FAILURE 1
+#endif
+
+static const char* usageMsg[] = {
 "usage: tiffset [options] filename",
 "where options are:",
 " -s <tagname> [count] <value>...   set the tag value",
@@ -47,16 +54,20 @@ static char* usageMsg[] = {
 " -d <dirno> set the directory",
 " -sd <diroff> set the subdirectory",
 " -sf <tagname> <filename>  read the tag value from file (for ASCII tags only)",
+" -h  this help screen",
 NULL
 };
 
 static void
-usage(void)
+usage(int code)
 {
 	int i;
+	FILE * out = (code == EXIT_SUCCESS) ? stdout : stderr;
+
+	fprintf(out, "%s\n\n", TIFFGetVersion());
 	for (i = 0; usageMsg[i]; i++)
-		fprintf(stderr, "%s\n", usageMsg[i]);
-	exit(-1);
+		fprintf(out, "%s\n", usageMsg[i]);
+	exit(code);
 }
 
 static const TIFFField *
@@ -84,11 +95,11 @@ main(int argc, char* argv[])
     int  arg_index;
 
     if (argc < 2)
-        usage();
+        usage(EXIT_FAILURE);
 
     tiff = TIFFOpen(argv[argc-1], "r+");
     if (tiff == NULL)
-        return 2;
+        return EXIT_FAILURE;
 
     for( arg_index = 1; arg_index < argc-1; arg_index++ ) {
 	if (strcmp(argv[arg_index],"-d") == 0 && arg_index < argc-2) {
@@ -96,7 +107,7 @@ main(int argc, char* argv[])
 	    if( TIFFSetDirectory(tiff, atoi(argv[arg_index]) ) != 1 )
             {
                fprintf( stderr, "Failed to set directory=%s\n", argv[arg_index] );
-               return 6;
+               return EXIT_FAILURE;
             }
 	    arg_index++;
 	}
@@ -105,7 +116,7 @@ main(int argc, char* argv[])
 	    if( TIFFSetSubDirectory(tiff, atoi(argv[arg_index]) ) != 1 )
             {
                fprintf( stderr, "Failed to set sub directory=%s\n", argv[arg_index] );
-               return 7;
+               return EXIT_FAILURE;
             }
 	    arg_index++;
 	}
@@ -117,7 +128,7 @@ main(int argc, char* argv[])
             tagname = argv[arg_index];
             fip = GetField(tiff, tagname);
             if (!fip)
-                return 3;
+               return EXIT_FAILURE;
 
             if (TIFFUnsetField(tiff, TIFFFieldTag(fip)) != 1)
             {
@@ -155,7 +166,7 @@ main(int argc, char* argv[])
                              "Number of tag values is not enough. "
                              "Expected %d values for %s tag, got %d\n",
                              wc, TIFFFieldName(fip), argc - arg_index);
-                    return 4;
+                    return EXIT_FAILURE;
                 }
                     
                 if (wc > 1 || TIFFFieldWriteCount(fip) == TIFF_VARIABLE) {
@@ -204,7 +215,7 @@ main(int argc, char* argv[])
                         if (!array) {
                                 fprintf(stderr, "No space for %s tag\n",
                                         tagname);
-                                return 4;
+                                return EXIT_FAILURE;
                         }
 
                         switch (TIFFFieldDataType(fip)) {
@@ -327,13 +338,13 @@ main(int argc, char* argv[])
             fip = GetField(tiff, argv[arg_index]);
 
             if (!fip)
-                return 3;
+                return EXIT_FAILURE;
 
             if (TIFFFieldDataType(fip) != TIFF_ASCII) {
                 fprintf( stderr,
                          "Only ASCII tags can be set from file. "
                          "%s is not ASCII tag.\n", TIFFFieldName(fip) );
-                return 5;
+                return EXIT_FAILURE;
             }
 
             arg_index++;
@@ -367,16 +378,18 @@ main(int argc, char* argv[])
 
             _TIFFfree( text );
             arg_index++;
+        } else if (strcmp(argv[arg_index],"-h") == 0 || strcmp(argv[arg_index],"--help") == 0) {
+            usage(EXIT_SUCCESS);
         } else {
             fprintf(stderr, "Unrecognised option: %s\n",
                     argv[arg_index]);
-            usage();
+            usage(EXIT_FAILURE);
         }
     }
 
     TIFFRewriteDirectory(tiff);
     TIFFClose(tiff);
-    return 0;
+    return EXIT_SUCCESS;
 }
 
 /* vim: set ts=8 sts=8 sw=8 noet: */