RSILVERMAN@eagle.wesleyan.edu (Richard Silverman) (06/06/89)
I am trying to use sdb under System V. I would like to patch the value of
a global variable. I have compiled & linked the image with the -g option.
I get the following:
% sdb -w imagefile
No core image
*:variable!1
No process and/or file
* ...
If I oblige it by starting a process running the image, then the command
works, but of course it only sets the variable in memory; I want to patch
the image file. The manual says that "if a process is running, all addresses
refer to memory; otherwise, they are file offsets" (or something like that).
What's more puzzling is that I made it work once! But I haven't the foggiest
notion what did it, and it doesn't work now. Can anyone enlighten me? Thanks,
Richard Silverman
arpa: rsilverman@eagle.wesleyan.edu Computing Center
bitnet: rsilverman@wesleyan Wesleyan University
CIS: [72727,453] Middletown, CT 06457RSILVERMAN@eagle.wesleyan.edu (Richard Silverman) (06/07/89)
(message to Bob Nicholls; I could not send this directly)
Bob,
Many thanks for clearing that up for me! Of course, the mystifying
"only time it worked" was when I had changed it by hand -- by initializing
it in the source and recompiling. I am not patching because I don't have
the source; it's just a quick way of setting the debug flag in a yacc-produced
parser without having to recompile it or alter the code to have a command-line
switch. Thanks again,
Richard Silverman
arpa: rsilverman@eagle.wesleyan.edu Computing Center
bitnet: rsilverman@wesleyan Wesleyan University
CIS: [72727,453] Middletown, CT 06457emuleomo@yes.rutgers.edu (Emuleomo) (06/09/89)
This may not be a strict followup to the sdb patch problem, but I am interested in knowing if there are any good _debuggers_ out there for SysV? I have used one called "dbx" and it blows "sdb" AWAY! Please try sending me mail on any nice ones you have come across. Also, can any debugger out there debug a CHILD process that is forked and execed? ThanX --Emuleomo O.O. (Email ==> emuleomo@yes.rutgers.edu)