Rob Landley writes:

Run this test, against both busybox and a non-busybox version of "tee".

while true; do i=$[$i+1]; echo "hello $i"; sleep 1; done | ./busybox tee

Now run the busybox one again with the following small patch applied:

diff --git a/coreutils/tee.c b/coreutils/tee.c
index bb28966..25c1087 100644 (file)
--- a/coreutils/tee.c
+++ b/coreutils/tee.c
@@ -78,7 +78,7 @@ int tee_main(int argc, char **argv)
        *p = NULL;                              /* Store the sentinal value. */
 
 #ifdef CONFIG_FEATURE_TEE_USE_BLOCK_IO
-       while ((c = fread(buf, 1, BUFSIZ, stdin)) != 0) {
+       while ((c = read(0, buf, BUFSIZ)) != 0) {
                for (p=files ; *p ; p++) {
                        fwrite(buf, 1, c, *p);
                }