Job control problem (Ctrl-z)

q14526 · 12-12-2006, 03:21 PM

I ahve a Linux PPC box with WindRiver kernel 2.6.10. The problem is if I am doing vi a file, when I am in command mode (not insert mode) I suppose to be able to suspend to the shell with Ctrl-z like any other Linux boxes(command :suspend also does not work). But I cannot on this box. Could somebody please tell me why and how to fix it or where to look at. This is for my work, embedded application. I have searched this forum for hours, went through all posts (search words: "job control" and Ctrl-z) one by one but did not found it. The issue is not just with vi, the issue is some how the process just ignore SIGSTOP or something like that but it is easiest to show with vi, it could be the same with cat command or any other commands. Thank you very much in advance. Please help me.

i_grok · 12-12-2006, 04:31 PM

It may have to do with what shell you are using. Try this:

Code:

chsh /bin/bash
vi MYFILE

See if CTRL-Z works now.

q14526 · 12-13-2006, 08:42 AM

Hi i_grok,
Thank for reply. My system has only BASH shell. It does not has chsh command either. Because it is embedded system I guess they strip everything out. If I enter bash -version, it show:
GNU bash, version 3.00.0(1)-release (powerpc-wrs-linux-gnu)
Could it has bug in "powerpc-wrs-linux-gnu" version? How can I prove that?
Please let me know if you have any other ideas. Thanks.

i_grok · 12-13-2006, 11:44 PM

Ok. Try to find out if CTRL-z works at all - does it work with commands other than vi? Try this:

Code:

cat
CTRL-z

If even that doesn't work then we know for sure bash is doing something weird. Does CTRL-/ work? How about CTRL-c?

q14526 · 12-15-2006, 09:27 AM

Hi i_grok,

Yes, the problem of ctrl-z is the same with cat. Ctrl-c and Ctrl-/ are OK.
However, I found out that if I replace the /bin/bash with "bash" from FC4 then Ctrl-z is OK. My guess is this "bash" was compiled with a cross compliler and therefore the option --enable-job-control (and may be other options as well) was disable since they can not tell if the system (can be either ppc or x86)would support job control. But I still can find that in the Makefile or configure, I am still searching if indeed that is the reason (The tool chain come pre-build).

Thank you very much for your help.