utils-std

commit: 388be371d91938897924756e705fbaaf959b6361
parent 81e55d1675082f9f25146e95c018753f0aa34358
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date:   Mon,  1 Apr 2024 20:38:15 +0200

cmd/cat: Write a clearer splice loop for fd_copy

- No more extra loop done with goto
- No more body-less while with a large function call as conditional
- Chain of if+default on errno changed to switch(errno)

Diffstat:
M
cmd/cat.c
39
++++++++++++++++++++-------------------

1 file changed, 20 insertions(+), 19 deletions(-)
diff --git a/cmd/cat.c b/cmd/cat.c
@@ -45,29 +45,30 @@ concat(int fd, const char *fdname)
 static int
 fd_copy(int fd, const char *fdname)
 {
-	ssize_t c = 0;
+	while(1)
+	{
+		assert(errno == 0);
+		ssize_t ret =
+		    splice(fd, NULL, 1, NULL, SIZE_MAX, SPLICE_F_MOVE | SPLICE_F_NONBLOCK | SPLICE_F_MORE);
 
-again:
-	assert(errno == 0);
-	while((c = splice(
-	           fd, NULL, 1, NULL, SIZE_MAX, SPLICE_F_MOVE | SPLICE_F_NONBLOCK | SPLICE_F_MORE)) > 0)
-		;
+		if(ret == 0) break;
 
-	if(c < 0)
-	{
-		if(errno == EINVAL)
+		if(ret < 0)
 		{
-			errno = 0;
-			return concat(fd, fdname);
-		}
-		if(errno == EAGAIN)
-		{
-			errno = 0;
-			goto again;
+			switch(errno)
+			{
+			case EINVAL:
+				errno = 0;
+				return concat(fd, fdname);
+			case EAGAIN:
+				errno = 0;
+				continue;
+			default:
+				fprintf(stderr, "cat: Error copying ‘%s’: %s\n", fdname, strerror(errno));
+				errno = 0;
+				return 1;
+			}
 		}
-		fprintf(stderr, "cat: Error copying ‘%s’: %s\n", fdname, strerror(errno));
-		errno = 0;
-		return 1;
 	}
 
 	return 0;