rgblink: improve file open error messages

src/link/mapfile.c

@@ -1,7 +1,9 @@
 #include <err.h>
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sysexits.h>
 
 #include "asmotor.h"
 
@@ -19,8 +21,9 @@ SetMapfileName(char *name)
 {
 	mf = fopen(name, "w");
 
-	if (!mf)
-		errx(5, "Unable to open mapfile for writing");
+	if (mf == NULL)
+		errx(EX_CANTCREAT, "Cannot open mapfile '%s' : %s", name,
+		    strerror(errno));
 }
 
 void 
@@ -28,8 +31,9 @@ SetSymfileName(char *name)
 {
 	sf = fopen(name, "w");
 
-	if (!sf)
-		errx(5, "Unable to open symfile for writing");
+	if (sf == NULL)
+		errx(EX_CANTCREAT, "Cannot open symfile '%' : %s", name,
+		    strerror(errno));
 
 	fprintf(sf, ";File generated by xLink v" LINK_VERSION "\n\n");
 }

src/link/object.c

@@ -4,9 +4,11 @@
  */
 
 #include <err.h>
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sysexits.h>
 
 #include "link/mylink.h"
 #include "link/main.h"
@@ -443,9 +445,9 @@ obj_Readfile(char *tzObjectfile)
 		oReadLib = 0;
 
 	pObjfile = fopen(tzObjectfile, "rb");
-	if (!pObjfile) {
-		errx(5, "Unable to open '%s'", tzObjectfile);
-	}
+	if (pObjfile == NULL)
+		errx(EX_NOINPUT, "Unable to open object '%s' : %s",
+		    tzObjectfile, strerror(errno));
 	obj_ReadOpenFile(pObjfile, tzObjectfile);
 	fclose(pObjfile);
 
@@ -493,6 +495,9 @@ lib_Readfile(char *tzLibfile)
 	oReadLib = 1;
 
 	pObjfile = fopen(tzLibfile, "rb");
+	if (pObjfile == NULL)
+		errx(EX_NOINPUT, "Unable to open object '%s' : %s",
+		    tzObjectfile, strerror(errno));
 	if (!pObjfile) {
 		errx(5, "Unable to open '%s'", tzLibfile);
 	}