Couple related things:
- Use err(3) everywhere.
For many of these errors we are not currently printing the errno
string. Is there any reason not to do so? The errno string is
useful.
- Set ifile/ofile to "stdin"/"stdout" if the user passes in
"-" to make the err(3) message a little more obvious.
- Add a usage() function.
ok?
Index: midicat.c
===================================================================
RCS file: /cvs/src/usr.bin/midicat/midicat.c,v
retrieving revision 1.4
diff -u -p -r1.4 midicat.c
--- midicat.c 30 Nov 2022 14:56:45 -0000 1.4
+++ midicat.c 30 Nov 2022 15:13:01 -0000
@@ -22,8 +22,7 @@
#include <unistd.h>
#include <string.h>
-char usagestr[] = "usage: midicat [-d] [-i in-file] [-o out-file] "
- "[-q in-port] [-q out-port]\n";
+void usage(void);
int
main(int argc, char **argv)
@@ -50,10 +49,8 @@ main(int argc, char **argv)
port0 = optarg;
else if (port1 == NULL)
port1 = optarg;
- else {
- fputs("too many -q options\n", stderr);
- return 1;
- }
+ else
+ errx(1, "too many -q options");
break;
case 'i':
ifile = optarg;
@@ -62,32 +59,25 @@ main(int argc, char **argv)
ofile = optarg;
break;
default:
- goto bad_usage;
+ usage();
}
}
argc -= optind;
argv += optind;
- if (argc != 0) {
- bad_usage:
- fputs(usagestr, stderr);
- return 1;
- }
+ if (argc != 0)
+ usage();
/* we don't support more than one data flow */
- if (ifile != NULL && ofile != NULL) {
- fputs("-i and -o are exclusive\n", stderr);
- return 1;
- }
+ if (ifile != NULL && ofile != NULL)
+ errx(1, "-i and -o are exclusive");
/* second port makes sense only for port-to-port transfers */
- if (port1 != NULL && !(ifile == NULL && ofile == NULL)) {
- fputs("too many -q options\n", stderr);
- return 1;
- }
+ if (port1 != NULL && !(ifile == NULL && ofile == NULL))
+ errx(1, "too many -q options");
/* if there're neither files nor ports, then we've nothing to do */
if (port0 == NULL && ifile == NULL && ofile == NULL)
- goto bad_usage;
+ usage();
/* if no port specified, use default one */
if (port0 == NULL)
@@ -95,24 +85,22 @@ 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);
- return 1;
- }
+ if (ifd == -1)
+ err(1, "%s", ifile);
}
} 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);
- return 1;
- }
+ if (ofd == -1)
+ err(1, "%s", ofile);
}
}
@@ -126,20 +114,16 @@ main(int argc, char **argv)
else
mode = MIO_IN;
ih = mio_open(port0, mode, 0);
- if (ih == NULL) {
- fprintf(stderr, "%s: couldn't open port\n", port0);
- return 1;
- }
+ if (ih == NULL)
+ err(1, "%s: couldn't open port", port0);
/* open second port, output only */
if (port1 == NULL)
oh = ih;
else {
oh = mio_open(port1, MIO_OUT, 0);
- if (oh == NULL) {
- fprintf(stderr, "%s: couldn't open port\n", port1);
- exit(1);
- }
+ if (oh == NULL)
+ err(1, "%s: couldn't open port", port1);
}
if (pledge("stdio", NULL) == -1)
@@ -152,26 +136,26 @@ main(int argc, char **argv)
if (len == 0)
break;
if (len == -1) {
- perror("stdin");
+ warn("%s", ifile);
break;
}
} else {
len = mio_read(ih, buf, sizeof(buf));
if (len == 0) {
- fprintf(stderr, "%s: disconnected\n", port0);
+ warn("%s: disconnected", port0);
break;
}
}
if (ofile != NULL) {
n = write(ofd, buf, len);
if (n != len) {
- fprintf(stderr, "%s: short write\n", ofile);
+ warn("%s: short write", ofile);
break;
}
} else {
n = mio_write(oh, buf, len);
if (n != len) {
- fprintf(stderr, "%s: disconnected\n", port1);
+ warn("%s: disconnected", port1);
break;
}
}
@@ -194,4 +178,12 @@ main(int argc, char **argv)
if (ofile)
close(ofd);
return 0;
+}
+
+void
+usage(void)
+{
+ fprintf(stderr, "usage: midicat [-d] [-i in-file] [-o out-file] "
+ "[-q in-port] [-q out-port]\n");
+ exit(1);
}
