Hi All,
Please find in attachment a new patch that replace a fix for a bug :
"echo -n | xargs -I% echo %" would SEG
Commit:
https://git.busybox.net/busybox/commit/findutils/xargs.c?id=6d777b75ed322ea5ef0d1674ddfee1b5713cb04f
Currently available solution fixes SEGV issue, but the execution of
'xargs -I' behavior is different than the xargs from (GNU findutils).
Please see the example:
~$ cat ~/tmp/xargs-test
--- start file xargs-test ---
line number 2
line number 4
--- end file xargs-test ---
* output from xargs (GNU findutils) 4.7.0:
~$ cat ~/tmp/xargs-test | /usr/bin/xargs -I % echo %
line number 2
line number 4
~$
* output xargs from BusyBox v1.30.1 (Ubuntu 1:1.30.1-4ubuntu6.1)
multi-call binary):
~$ cat ~/tmp/xargs-test | busybox xargs -I % echo %echo %
~$
I thing that xargs from GNY findutils is expected. The patch:
0001-busybox-xargs-I-ignore-empty-lines.patch
remove the changes within the commit
6d777b75ed322ea5ef0d1674ddfee1b5713cb04f and introduce new behavior -
empty lines are ignored.
Regards,
Franciszek
--
Franciszek Koltuniuk
w: consult.red <https://consult.red>
e: franciszek.koltun...@consult.red
>From e8038435e4c63af1b696f0f5ef60e5b16cf0000e Mon Sep 17 00:00:00 2001
From: Franciszek Koltuniuk <franciszek.koltun...@consult.red>
Date: Tue, 22 Sep 2020 15:18:48 +0200
Subject: [PATCH] busybox `xargs -I` - ignore empty lines
Make 'xargs -I' behaviur like GNU findutils - ignore empty lines and replace the fix for the SEGV bug:
commit: 6d777b75ed322ea5ef0d1674ddfee1b5713cb04f
$ echo -n | xargs -I % echo %
Segmentation fault
---
findutils/xargs.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/findutils/xargs.c b/findutils/xargs.c
index ff04bfe7c..fd6abe1ee 100644
--- a/findutils/xargs.c
+++ b/findutils/xargs.c
@@ -106,6 +106,7 @@ struct globals {
char **argv;
const char *repl_str;
char eol_ch;
+ char eof;
#endif
const char *eof_str;
int idx;
@@ -128,6 +129,7 @@ struct globals {
setup_common_bufsiz(); \
IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.repl_str = "{}";) \
IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.eol_ch = '\n';) \
+ IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.eof = 0;) \
/* Even zero values are set because we are NOEXEC applet */ \
G.eof_str = NULL; \
G.idx = 0; \
@@ -467,8 +469,10 @@ static char* FAST_FUNC process_stdin_with_replace(int n_max_chars, int n_max_arg
while (1) {
int c = getchar();
if (c == EOF || c == G.eol_ch) {
- if (p == buf)
+ if (p == buf) {
+ G.eof = (c == EOF); /* check for EOF */
goto ret; /* empty line */
+ }
c = '\0';
}
*p++ = c;
@@ -697,9 +701,6 @@ int xargs_main(int argc UNUSED_PARAM, char **argv)
G.args = NULL;
G.argv = argv;
read_args = process_stdin_with_replace;
- /* Make -I imply -r. GNU findutils seems to do the same: */
- /* (otherwise "echo -n | xargs -I% echo %" would SEGV) */
- opt |= OPT_NO_EMPTY;
} else
#endif
{
@@ -726,6 +727,14 @@ int xargs_main(int argc UNUSED_PARAM, char **argv)
if (!G.args[initial_idx]) { /* not even one ARG was added? */
if (*rem != '\0')
bb_simple_error_msg_and_die("argument line too long");
+#if ENABLE_FEATURE_XARGS_SUPPORT_REPL_STR
+ if (opt & (OPT_REPLSTR | OPT_REPLSTR1)) {
+ if(G.eof)
+ break; /* exit on EOF */
+ else
+ continue; /* ignore empty line - otherwise "echo -n | xargs -I% echo %" would SEGV */
+ }
+#endif
if (opt & OPT_NO_EMPTY)
break;
}
--
2.25.1
_______________________________________________
busybox mailing list
busybox@busybox.net
http://lists.busybox.net/mailman/listinfo/busybox
