[hackers] [sbase] dd: Consider block count in inner read loop || Michael Forney

From: <git_AT_suckless.org>
Date: Thu, 13 Apr 2023 05:50:48 +0200 (CEST)

commit fb16e7c6ad0e8d27cba8ee6279f71f88c7f95fd7
Author: Michael Forney <mforney_AT_mforney.org>
AuthorDate: Wed Apr 12 20:13:51 2023 -0700
Commit: Michael Forney <mforney_AT_mforney.org>
CommitDate: Wed Apr 12 20:47:34 2023 -0700

    dd: Consider block count in inner read loop
    
    When ibs is smaller than obs, checking the block count in the outer
    loop is not sufficient; we need to break out of the inner read loop
    once we've read the specified number of blocks.
    
    Thanks to phoebos for reporting this issue.

diff --git a/dd.c b/dd.c
index 350843b..36eb409 100644
--- a/dd.c
+++ b/dd.c
_AT_@ -173,8 +173,12 @@ main(int argc, char *argv[])
                         eprintf("lseek:");
                 /* XXX: handle non-seekable files */
         }
- while (!eof && (count == -1 || ifull + ipart < count)) {
+ while (!eof) {
                 while (ipos - opos < obs) {
+ if (ifull + ipart == count) {
+ eof = 1;
+ break;
+ }
                         ret = read(ifd, buf + ipos, ibs);
                         if (ret == 0) {
                                 eof = 1;
Received on Thu Apr 13 2023 - 05:50:48 CEST