diff --git a/floatimg.h b/floatimg.h
index fce4fa0..91ba78d 100644
--- a/floatimg.h
+++ b/floatimg.h
@@ -4,7 +4,7 @@
  *	http://la.buvette.org/photos/cumul
  */
 
-#define		FIMG_VERSION	170
+#define		FIMG_VERSION	171
 
 /*
  *	in memory descriptor
@@ -22,7 +22,7 @@ typedef struct {
 	} FloatImg;
 
 /*
- *	fimg file header
+ *	fimg file header (short version)
  */
 typedef struct {
 	char		magic[8];
diff --git a/lib/README.md b/lib/README.md
new file mode 100644
index 0000000..e69de29
diff --git a/lib/fimg-pnm.c b/lib/fimg-pnm.c
index 58af3e2..2d248e6 100644
--- a/lib/fimg-pnm.c
+++ b/lib/fimg-pnm.c
@@ -232,7 +232,7 @@ if (NULL==(fp=fopen(fname, "w"))) {
 	return -2;
 	}
 
-fprintf(fp, "P2\n%d\n%d\n65535\n\n", psrc->width, psrc->height);
+fprintf(fp, "P2\n%d %d\n65535\n\n", psrc->width, psrc->height);
 area = psrc->width * psrc->height;
 maxval = fimg_get_plane_maxvalue(psrc, plane);
 fk = maxval / 65535.0;
@@ -250,7 +250,7 @@ for (idx=0; idx<area; idx++) {
 
 fclose(fp);
 
-return -1;
+return 0;
 }
 /* ---------------------------------------------------------------- */
 /* 	nouveau 10 fevrier 2022 */
diff --git a/lib/t.c b/lib/t.c
index 8c510af..0190060 100644
--- a/lib/t.c
+++ b/lib/t.c
@@ -28,8 +28,20 @@ if (foo) {
 	return -6;
 	}
 foo = fimg_save_plane_as_pgm(&image, "red.pgm", 'r');
+if (foo) {
+	fprintf(stderr, "err save red %d\n", foo);
+	return -6;
+	}
 foo = fimg_save_plane_as_pgm(&image, "green.pgm", 'g');
+if (foo) {
+	fprintf(stderr, "err save green %d\n", foo);
+	return -6;
+	}
 foo = fimg_save_plane_as_pgm(&image, "blue.pgm", 'b');
+if (foo) {
+	fprintf(stderr, "err save blue %d\n", foo);
+	return -6;
+	}
 
 return 0;
 }