Audit tee(1)

1) "duplicate" implies that you can only specify two outputs,
   "multiply" is a better word describing the functionality.
2) fix other wording in the manpage
3) fix usage()
4) reorder local variables
5) fix sizeof() style
6) we need argv later, don't increment argv and rather iterate
   over argc.
7) Improve error messages, print the filename which the write
   failed to instead of printing the buffer itself (how much
   sense does that make, printing 1024 Bytes of garbage?).
   Also, give the name of the function which failed.

README

@@ -73,7 +73,7 @@ The following tools are implemented ('*' == finished, '#' == UTF-8 support,
 =*  sync            non-posix                    none
 =*  tail            yes                          none
 =*  tar             non-posix                    none
-=*  tee             yes                          none
+=*| tee             yes                          none
 =*  test            yes                          none
 =   time            yes                          none
 =*  touch           yes                          none

tee.1

@@ -1,16 +1,16 @@
-.Dd January 23, 2015
+.Dd March 4, 2015
 .Dt TEE 1
 .Os sbase
 .Sh NAME
 .Nm tee
-.Nd duplicate stdin
+.Nd multiply stdin
 .Sh SYNOPSIS
 .Nm
 .Op Fl ai
 .Op Ar file ...
 .Sh DESCRIPTION
 .Nm
-writes from stdin to stdout and each
+reads from stdin and writes to stdout and each
 .Ar file .
 .Sh OPTIONS
 .Bl -tag -width Ds

tee.c

@@ -7,17 +7,16 @@
 static void
 usage(void)
 {
-	eprintf("usage: %s [-ai] [file...]\n", argv0);
+	eprintf("usage: %s [-ai] [file ...]\n", argv0);
 }
 
 int
 main(int argc, char *argv[])
 {
+	FILE **fps = NULL;
+	size_t i, n, nfps;
 	int aflag = 0, iflag = 0;
 	char buf[BUFSIZ];
-	int i, nfps;
-	size_t n;
-	FILE **fps = NULL;
 
 	ARGBEGIN {
 	case 'a':
@@ -33,21 +32,22 @@ main(int argc, char *argv[])
 	if (iflag && signal(SIGINT, SIG_IGN) == SIG_ERR)
 		eprintf("signal:");
 	nfps = argc + 1;
-	fps = ecalloc(nfps, sizeof *fps);
+	fps = ecalloc(nfps, sizeof(*fps));
 
-	for (i = 0; argc > 0; argc--, argv++, i++)
-		if (!(fps[i] = fopen(*argv, aflag ? "a" : "w")))
-			eprintf("fopen %s:", *argv);
+	for (i = 0; i < argc; i++)
+		if (!(fps[i] = fopen(argv[i], aflag ? "a" : "w")))
+			eprintf("fopen %s:", argv[i]);
 	fps[i] = stdout;
 
-	while ((n = fread(buf, 1, sizeof buf, stdin)) > 0) {
+	while ((n = fread(buf, 1, sizeof(buf), stdin))) {
 		for (i = 0; i < nfps; i++) {
-			if (fwrite(buf, 1, n, fps[i]) != n)
-				eprintf("%s: write error:", buf);
+			if (fwrite(buf, 1, n, fps[i]) == n)
+				continue;
+			eprintf("fwrite %s:", (i != argc) ? argv[i] : "<stdout>");
 		}
 	}
 	if (ferror(stdin))
-		eprintf("<stdin>: read error:");
+		eprintf("fread <stdin>:");
 
 	return 0;
 }