add pledge(2) to midiplay(1)

[Ricardo Mestre]

Hi,

This adds pledge to midiplay, it only needs stdio rpath if reading
files, otherwise (playing the sample or from stdin) only stdio is
needed.

OK?

Index: midiplay.c
===================================================================
RCS file: /cvs/src/usr.bin/midiplay/midiplay.c,v
retrieving revision 1.19
diff -u -p -u -r1.19 midiplay.c
--- midiplay.c  24 Apr 2017 06:45:56 -0000      1.19
+++ midiplay.c  20 Jul 2018 08:08:27 -0000
@@ -446,7 +446,7 @@ main(int argc, char **argv)
        }
        argc -= optind;
        argv += optind;
-    
+
        hdl = mio_open(file, MIO_OUT, 0);
        if (hdl == NULL)
                errx(1, "failed to open MIDI output");
@@ -463,11 +463,22 @@ main(int argc, char **argv)
        if (setitimer(ITIMER_REAL, &it, NULL) < 0)
                err(1, "setitimer");
 
-       if (example)
+       if (example) {
+               if (pledge("stdio", NULL) == -1)
+                       err(1, "pledge");
+
                playdata(sample, sizeof sample, "<Gubben Noa>");
-       else if (argc == 0)
+       }
+       else if (argc == 0) {
+               if (pledge("stdio", NULL) == -1)
+                       err(1, "pledge");
+
                playfile(stdin, "<stdin>");
-       else
+       }
+       else {
+               if (pledge("stdio rpath", NULL) == -1)
+                       err(1, "pledge");
+
                while (argc--) {
                        f = fopen(*argv, "r");
                        if (f == NULL)
@@ -478,6 +489,7 @@ main(int argc, char **argv)
                        }
                        argv++;
                }
+       }
 
        exit(0);
 }