midicat(1): set ifile/ofile to "stdin"/"stdout" if it is an en-dash ("-")

This makes error messages a little bit more intuitive.  Instead of, e.g.:

midicat: -: No space left on device

you get:

midicat: stdout: No space left on device

Link: https://marc.info/?l=openbsd-tech&m=166982129428027&w=2
ok millert@ kn@ ratchov@

diff --git a/usr.bin/midicat/midicat.c b/usr.bin/midicat/midicat.c
index 21bb05a..7c40dd7 100644 (file)
--- a/usr.bin/midicat/midicat.c
+++ b/usr.bin/midicat/midicat.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: midicat.c,v 1.5 2022/12/02 22:21:35 cheloha Exp $     */
+/*     $OpenBSD: midicat.c,v 1.6 2022/12/02 22:29:59 cheloha Exp $     */
 /*
  * Copyright (c) 2015 Alexandre Ratchov <alex@caoua.org>
  *
@@ -92,9 +92,10 @@ main(int argc, char **argv)
 
        /* open input or output file (if any) */
        if (ifile) {
-               if (strcmp(ifile, "-") == 0)
+               if (strcmp(ifile, "-") == 0) {
+                       ifile = "stdin";
                        ifd = STDIN_FILENO;
-               else {
+               } else {
                        ifd = open(ifile, O_RDONLY);
                        if (ifd == -1) {
                                perror(ifile);
@@ -102,9 +103,10 @@ main(int argc, char **argv)
                        }
                }
        } else if (ofile) {
-               if (strcmp(ofile, "-") == 0)
+               if (strcmp(ofile, "-") == 0) {
+                       ofile = "stdout";
                        ofd = STDOUT_FILENO;
-               else {
+               } else {
                        ofd = open(ofile, O_WRONLY | O_CREAT | O_TRUNC, 0666);
                        if (ofd == -1) {
                                perror(ofile);