nc -d -l does not return data (only empty strings)
Bug #1656785 reported by
Stefan Bader
This bug affects 1 person
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| netcat-openbsd (Debian) |
Won't Fix
|
Unknown
|
|||
| netcat-openbsd (Ubuntu) |
Fix Released
|
Undecided
|
Unassigned | ||
Bug Description
The Zesty (17.04) version of nc (1.130-1ubuntu1) no longer returns the received data when using the '-d' (do not listen on stdin) flag together with the '-l' (listen on socket) flag. This used to work in previous releases (1.105-7ubuntu1 Trusty-Yakkety). In fact, in the previous version, the '-d' flag seems to be required to make the data transfer more reliable in scripts.
Testcase: Attached script passes on older versions, fails with the current version of nc.
Revision history for this message
| Stefan Bader (smb) wrote | #1 |
| Changed in netcat-openbsd (Debian): | |
| status: | Unknown → New |
Revision history for this message
| Stefan Bader (smb) wrote | #2 |
Revision history for this message
| Stefan Bader (smb) wrote | #3 |
| tags: | added: patch |
| Changed in netcat-openbsd (Debian): | |
| status: | New → Fix Released |
| Changed in netcat-openbsd (Debian): | |
| status: | Fix Released → New |
| Changed in netcat-openbsd (Debian): | |
| status: | New → Won't Fix |
Revision history for this message
| Aron Xu (happyaron) wrote | #4 |
| Changed in netcat-openbsd (Ubuntu): | |
| status: | New → Fix Released |
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Added to the Debian bug report. Basically the output problem is related to a Debian add-on patch to introduce the -q# option (delayed exit) which has been incorrectly adapted to the new code.
However while testing a possible solution I found that upstream changed the default behaviour of nc to not shutdown the net socket when the local input stream closes. Now this requires using -N to get this back.